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Sample records for endemic bornean frog

  1. Pure Ultrasonic Communication in an Endemic Bornean Frog

    PubMed Central

    Arch, Victoria S.; Grafe, T. Ulmar; Gridi-Papp, Marcos; Narins, Peter M.

    2009-01-01

    Huia cavitympanum, an endemic Bornean frog, is the first amphibian species known to emit exclusively ultrasonic (i.e., >20 kHz) vocal signals. To test the hypothesis that these frogs use purely ultrasonic vocalizations for intraspecific communication, we performed playback experiments with male frogs in their natural calling sites. We found that the frogs respond with increased calling to broadcasts of conspecific calls containing only ultrasound. The field study was complemented by electrophysiological recordings from the auditory midbrain and by laser Doppler vibrometer measurements of the tympanic membrane's response to acoustic stimulation. These measurements revealed that the frog's auditory system is broadly tuned over high frequencies, with peak sensitivity occurring within the ultrasonic frequency range. Our results demonstrate that H. cavitympanum is the first non-mammalian vertebrate described to communicate with purely ultrasonic acoustic signals. These data suggest that further examination of the similarities and differences in the high-frequency/ultrasonic communication systems of H. cavitympanum and Odorrana tormota, an unrelated frog species that produces and detects ultrasound but does not emit exclusively ultrasonic calls, will afford new insights into the mechanisms underlying vertebrate high-frequency communication. PMID:19401782

  2. Unusually high genetic diversity in the Bornean Limnonectes kuhlii-like fanged frogs (Anura: Dicroglossidae).

    PubMed

    Matsui, Masafumi; Kuraishi, Norihiro; Eto, Koshiro; Hamidy, Amir; Nishikawa, Kanto; Shimada, Tomohiko; Yambun, Paul; Vairappan, Charles Santhanaraju; Hossman, Mohamad Yazid Bin

    2016-09-01

    A fanged frog Limnonectes kuhlii was once thought to be wide-ranging in Southeast Asia, but is now confined to its type locality Java through recent phylogenetic studies, which clarified heterospecific status of non-Javanese populations, and monophyly of Bornean populations. However, large genetic differences among Bornean populations suggest occurrence of cryptic species, which we test using dense geographic sampling. We estimated the phylogenetic relationships among samples of Bornean populations together with their putative relatives from the continental Southeast Asia, using 2517bp sequences of the 12S rRNA, tRNA(val), and 16S rRNA of mitochondrial DNA, and 2367bp sequences of the NCX1, POMC, and RAG1 of nuclear genes. In the mtDNA trees, Bornean L. kuhlii-like frogs formed a monophyletic group split into 18 species lineages including L. hikidai, with the deepest phylogenetic split separating L. cintalubang from the remaining species. Almost all of these lineages co-occur geographically, and two to three lineages were found syntopically in each locality. Co-occurrence of more than one lineage may be maintained by differential morphology and microhabitat selection. These syntopic lineages should be regarded as distinct species. Our results clearly indicate that taxonomic revision is urgent to clarify many evolutionary problems of Bornean L. kuhlii-like frogs. PMID:27374495

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

    PubMed

    Retallick, Richard W R; McCallum, Hamish; Speare, Rick

    2004-11-01

    The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985-1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis. PMID:15502873

  4. Endemic Infection of the Amphibian Chytrid Fungus in a Frog Community Post-Decline

    PubMed Central

    2004-01-01

    The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985–1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985–1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis. PMID:15502873

  5. Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

    PubMed

    Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

    2015-01-01

    We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes. PMID:26250010

  6. Genetic diversity and differentiation of the Ryukyu endemic frog Babina holsti as revealed by mitochondrial DNA.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Nakata, Katsushi

    2014-02-01

    We surveyed the genetic diversity and genetic differentiation of an endangered frog, Babina holsti, endemic to Okinawajima and Tokashikijima Islands of the Ryukyus, to elucidate its divergence history and obtain basic data for its conservation. Genetic differentiation between the two island lineages is moderate (3.1% p-distance in the cyt b gene). This result suggests that the two island lineages have been isolated between the late Pliocene and the middle Pleistocene and have never migrated between the current northern part of Okinawajima and Tokashikijima Islands, which were once connected in the late Pleistocene glacial age. On Okinawajima Island, the southernmost sample was constituted by a unique haplotype, without considerable genetic distance from haplotypes detected from northern samples. This unique haplotype composition in the southernmost sample would have resulted from the restricted gene flow between the southernmost population and the other populations in Okinawajima Island. Furthermore, the absence of genetic diversity within the southernmost sample indicates that this population has recently experienced population size reduction, possibly by predation pressure from an introduced mongoose, which is more abundant in the southern part than in the northern part of the island. Lower genetic diversity in the Tokashikijima sample implies a small effective population size for mitochondrial DNA (mtDNA) in B. holsti on the island. Immediate conservation measures should be taken for the populations from the southernmost range in Okinawajima and Tokashikijima. PMID:24521314

  7. Phylogeny of the island archipelago frog genus Sanguirana: Another endemic Philippine radiation that diversified 'Out-of-Palawan'.

    PubMed

    Brown, Rafe M; Su, Yong-Chao; Barger, Brenna; Siler, Cameron D; Sanguila, Marites B; Diesmos, Arvin C; Blackburn, David C

    2016-01-01

    Recent higher-level frog phylogenetic analyses have included a few members of the endemic Philippine frog genus Sanguirana. Although the monophyly of the group has never been disputed, the recent phylogenetically-supported inclusion of the Palawan Wood Frog (Sanguirana sanguinea) in this clade was highly unexpected. In addition, species boundaries and relationships remain unclear and new species continue to be discovered. We estimate the phylogeny for this endemic Philippine genus using two mitochondrial gene regions and six nuclear loci and complete sampling for all known species. We use a time-calibrated Bayesian estimate of phylogeny and model-testing approach to biogeographic inference to infer ancestral areas and probable means of diversification. These analyses identify Sanguirana as an additional clade for which the 'Out-of-Palawan' biogeographic scenario is unambiguously preferred. This study lends additional support to recent work suggesting that a substantial portion of Philippine vertebrate megadiversity originated via colonization of the archipelago from the Palawan microcontinent, with subsequent invasion of oceanic islands (e.g., range expansion over Huxley's Modification of Wallace's Line), numerous instances of overwater dispersal, and geographic radiation across the archipelago. PMID:26477738

  8. Vocal Behavior of the Elusive Purple Frog of India (Nasikabatrachus sahyadrensis), a Fossorial Species Endemic to the Western Ghats

    PubMed Central

    Thomas, Ashish; Suyesh, Robin; Biju, S. D.; Bee, Mark A.

    2014-01-01

    Quantitative descriptions of animal vocalizations can inform an understanding of their evolutionary functions, the mechanisms for their production and perception, and their potential utility in taxonomy, population monitoring, and conservation. The goal of this study was to provide the first acoustical and statistical analysis of the advertisement calls of Nasikabatrachus sahyadrensis. Commonly known as the Indian purple frog, N. sahyadrensis is an endangered species endemic to the Western Ghats of India. As the only known species in its family (Nasikabatrachidae), it has ancient evolutionary ties to frogs restricted to the Seychelles archipelago (Sooglossidae). The role of vocalizations in the behavior of this unique species poses interesting questions, as the animal is fossorial and potentially earless and it breeds explosively above the soil for only about two weeks a year. In this study, we quantified 19 acoustic properties of 208 calls recorded from 10 males. Vocalizations were organized into distinct call groups typically composed of two to six short (59 ms), pulsatile calls, each consisting of about five to seven pulses produced at a rate of about 106 pulses/s. The frequency content of the call consisted of a single dominant peak between 1200–1300 Hz and there was no frequency modulation. The patterns of variation within and among individuals were typical of those seen in other frogs. Few of the properties we measured were related to temperature, body size, or condition, though there was little variation in temperature. Field observations and recordings of captive individuals indicated that males engaged in both antiphonal calling and call overlap with nearby calling neighbors. We discuss our findings in relation to previous work on vocal behavior in other fossorial frogs and in sooglossid frogs. PMID:24516517

  9. Vocal behavior of the elusive purple frog of India (Nasikabatrachus sahyadrensis), a fossorial species endemic to the Western Ghats.

    PubMed

    Thomas, Ashish; Suyesh, Robin; Biju, S D; Bee, Mark A

    2014-01-01

    Quantitative descriptions of animal vocalizations can inform an understanding of their evolutionary functions, the mechanisms for their production and perception, and their potential utility in taxonomy, population monitoring, and conservation. The goal of this study was to provide the first acoustical and statistical analysis of the advertisement calls of Nasikabatrachus sahyadrensis. Commonly known as the Indian purple frog, N. sahyadrensis is an endangered species endemic to the Western Ghats of India. As the only known species in its family (Nasikabatrachidae), it has ancient evolutionary ties to frogs restricted to the Seychelles archipelago (Sooglossidae). The role of vocalizations in the behavior of this unique species poses interesting questions, as the animal is fossorial and potentially earless and it breeds explosively above the soil for only about two weeks a year. In this study, we quantified 19 acoustic properties of 208 calls recorded from 10 males. Vocalizations were organized into distinct call groups typically composed of two to six short (59 ms), pulsatile calls, each consisting of about five to seven pulses produced at a rate of about 106 pulses/s. The frequency content of the call consisted of a single dominant peak between 1200-1300 Hz and there was no frequency modulation. The patterns of variation within and among individuals were typical of those seen in other frogs. Few of the properties we measured were related to temperature, body size, or condition, though there was little variation in temperature. Field observations and recordings of captive individuals indicated that males engaged in both antiphonal calling and call overlap with nearby calling neighbors. We discuss our findings in relation to previous work on vocal behavior in other fossorial frogs and in sooglossid frogs. PMID:24516517

  10. Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest

    PubMed Central

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2015-01-01

    The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands. PMID:25920672

  11. Ancient tepui summits harbor young rather than old lineages of endemic frogs.

    PubMed

    Salerno, Patricia E; Ron, Santiago R; Señaris, J Celsa; Rojas-Runjaic, Fernando J M; Noonan, Brice P; Cannatella, David C

    2012-10-01

    The flattop mountains (tepuis) of South America are ancient remnants of the Precambrian Guiana Shield plateau. The tepui summits, isolated by their surrounding cliffs that can be up to 1000 m tall, are thought of as "islands in the sky," harboring relict flora and fauna that underwent vicariant speciation due to plateau fragmentation. High endemicity atop tepui summits support the idea of an ancient "Lost World" biota. However, recent work suggests that dispersal between lowlands and summits has occurred long after tepui formation indicating that tepui summits may not be as isolated from the lowlands as researchers have long suggested. Neither view of the origin of the tepui biota (i.e., ancient vicariance vs. recent dispersal) has strong empirical support owing to a lack of studies. We test diversification hypotheses of the Guiana Shield highlands by estimating divergence times of an endemic group of treefrogs, Tepuihyla. We find that diversification of this group does not support an ancient origin for this taxon; instead, divergence times among the highland species are 2-5 Ma. Our data indicate that most highland speciation occurred during the Pliocene. Thus, this unparalleled landscape known as "The Lost World" is inhabited, in part, not by Early Tertiary relicts but neoendemics. PMID:23025594

  12. Effects of Pleistocene glaciations and rivers on the population structure of Bornean orangutans (Pongo pygmaeus)

    PubMed Central

    Arora, Natasha; Nater, Alexander; van Schaik, Carel P.; Willems, Erik P.; van Noordwijk, Maria A.; Goossens, Benoit; Morf, Nadja; Bastian, Meredith; Knott, Cheryl; Morrogh-Bernard, Helen; Kuze, Noko; Kanamori, Tomoko; Pamungkas, Joko; Perwitasari-Farajallah, Dyah; Verschoor, Ernst; Warren, Kristin; Krützen, Michael

    2010-01-01

    Sundaland, a tropical hotspot of biodiversity comprising Borneo and Sumatra among other islands, the Malay Peninsula, and a shallow sea, has been subject to dramatic environmental processes. Thus, it presents an ideal opportunity to investigate the role of environmental mechanisms in shaping species distribution and diversity. We investigated the population structure and underlying mechanisms of an insular endemic, the Bornean orangutan (Pongo pygmaeus). Phylogenetic reconstructions based on mtDNA sequences from 211 wild orangutans covering the entire range of the species indicate an unexpectedly recent common ancestor of Bornean orangutans 176 ka (95% highest posterior density, 72–322 ka), pointing to a Pleistocene refugium. High mtDNA differentiation among populations and rare haplotype sharing is consistent with a pattern of strong female philopatry. This is corroborated by isolation by distance tests, which show a significant correlation between mtDNA divergence and distance and a strong effect of rivers as barriers for female movement. Both frequency-based and Bayesian clustering analyses using as many as 25 nuclear microsatellite loci revealed a significant separation among all populations, as well as a small degree of male-mediated gene flow. This study highlights the unique effects of environmental and biological features on the evolutionary history of Bornean orangutans, a highly endangered species particularly vulnerable to future climate and anthropogenic change as an insular endemic. PMID:21098261

  13. Sylvatic transmission of arboviruses among Bornean orangutans.

    PubMed

    Wolfe, N D; Kilbourn, A M; Karesh, W B; Rahman, H A; Bosi, E J; Cropp, B C; Andau, M; Spielman, A; Gubler, D J

    2001-01-01

    Wild populations of nonhuman primates live in regions of sylvatic arbovirus transmission. To assess the status of arbovirus transmission in Bornean forests and the susceptibility of wild orangutans to arboviral infection, blood samples of wild orangutans, semi-captive orangutans, and humans were examined. Samples were tested by plaque reduction neutralization test for antibodies to viruses representing three families (Flaviviridae, Alphaviridae, and Bunyaviridae), including dengue-2, Japanese encephalitis, Zika, Langat, Tembusu, Sindbis, Chikungunya, and Batai viruses. Both wild and semi-captive orangutan groups as well as local human populations showed serologic evidence of arbovirus infection. The presence of neutralizing antibodies among wild orangutans strongly suggests the existence of sylvatic cycles for dengue, Japanese encephalitis, and sindbis viruses in North Borneo. The present study demonstrates that orangutans are susceptible to arboviralinfections in the wild, although the impact of arboviral infections on this endangered ape remain unknown. PMID:11463123

  14. Complete mitochondrial genome of the Greek marsh frog Pelophylax cretensis (Anura, Ranidae).

    PubMed

    Hofman, Sebastian; Pabijan, Maciej; Osikowski, Artur; Szymura, Jacek M

    2016-05-01

    We sequenced the complete mitochondrial genome of the Greek marsh frog Pelophylax cretensis, a water frog species endemic to the island of Crete. The genome sequence was 17,829 bp in size, and the gene order and contents were identical to those of previously reported mitochondrial genomes of other water frog species. This is the first complete mitogenome (i.e. including control region) described for western Palaearctic water frogs. PMID:25329260

  15. Fantastic Frogs!

    ERIC Educational Resources Information Center

    Scott, Kym

    2002-01-01

    Number rhymes can be used in many exciting and different ways to support the early learning goals for mathematics. The rhyme "five little speckled frogs" provides the theme for this display, which was set up in Lewisham's professional development center. It provides a range of ideas which would help develop young children's mathematical learning…

  16. Mitochondrial DNA sequence analyses in Bornean sucker fishes (Balitoridae: Teleostei: Gastromyzontinae).

    PubMed

    Sulaiman, Zohrah Haji; Hui, Tan Heok; Lim, Kelvin K P; Ng, Peter K L

    2006-03-01

    Phylogenetic relationships among Bornean sucker fishes (Teleostei: Balitoridae: Gastromyzontinae) were investigated by comparing cytochrome b gene sequences from eight species. The results were in general agreement with previous morphology-based studies. It was found that the genera Gastromyzon and Neogastromyzon are both monophyletic and that the Chinese homalopterid Crossostoma lacustre (Homalopterinae) is not related to the Bornean species. This molecular-level study of cytochrome b gene variation in Bornean gastromyzontins will undoubtedly help to shed light on the molecular systematics of this unique freshwater fish. PMID:21395984

  17. Three new cembranoids from the Bornean soft coral Nephthea sp.

    PubMed

    Ishii, Takahiro; Kamada, Takashi; Vairappan, Charles S

    2016-05-01

    Three new cembranoid diterpenes, 10-hydroxy-nephthenol acetate (1), 7,8-epoxy-10-hydroxy-nephthenol acetate (2), and 6-acetoxy-7,8-epoxy-10-hydroxy-nephthenol acetate (3), along with a known compound, 6-acetoxy-7,8-epoxy-nephthenol acetate (4), were isolated from the Bornean soft coral Nephthea sp. Antibacterial and anticancer activities were exhibited by compounds 1 and 2 against Staphylococcus aureus (ATCC 6538)/Escherichia coli (ATCC 13311) and Hela/MCF-7, respectively. PMID:26983053

  18. Complete mitochondrial genomes of the tooth of a poached Bornean banteng (Bos javanicus lowi; Cetartiodactyla, Bovidae).

    PubMed

    Ishige, Taichiro; Gakuhari, Takashi; Hanzawa, Kei; Kono, Tomohiro; Sunjoto, Indra; Sukor, Jum Rafiah Abdul; Ahmad, Abdul Hamid; Matsubayashi, Hisashi

    2016-07-01

    Here we report the complete mitochondrial genome of the Bornean banteng Bos javanicus lowi (Cetartiodactyla, Bovidae), which was determined using next-generation sequencing. The mitochondrial genome is 16,344 bp in length containing 13 protein-coding genes, 21 tRNAs and 2 rRNAs. It shows the typical pattern of bovine mitochondrial arrangement. Phylogenetic tree analysis of complete mtDNA sequences showed that Bornean banteng is more closely related to gaur than to other banteng subspecies. Divergence dating indicated that Bornean banteng and gaur diverged from their common ancestor approximately 5.03 million years ago. These results suggest that Bornean banteng might be a distinct species in need of conservation. PMID:26075477

  19. Carbon accumulation and allocation in a primary Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, A.; Komatsu, H.; Kume, T.; Ohashi, M.; Nakagawa, M.; Otsuki, K.; Kumagai, T.

    2010-12-01

    To develop our knowledge of global carbon cycling, it is important to know all components of allocated carbon in tropical rainforests because of their enormous accumulation and elimination. Our goals in this study are to estimate carbon allocation (i.e. carbon flux to aboveground biomass increment, litterfall, aboveground plant respiration and belowground) and compare GPP based on biometric and flux measurement in a primary Bornean tropical rainforest. GPP estimated by biometric method (35.39 tCha-2yr-1) was similar to that measured by flux measurement (31.56 tCha-2yr-1). Mean annual aboveground biomass increment (2.77 tCha-2yr-1) was reasonable compared to former literatures in spite of larger aboveground biomass (272 tCha-2yr-1). Ratio of TBCF to GPP (0.55) was extremely high. These results suggested that considerable carbon is allocated to belowground, causing low productivity of aboveground biomass.

  20. Frog eat frog: exploring variables influencing anurophagy.

    PubMed

    Measey, G John; Vimercati, Giovanni; de Villiers, F André; Mokhatla, Mohlamatsane M; Davies, Sarah J; Edwards, Shelley; Altwegg, Res

    2015-01-01

    Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species. PMID:26336644

  1. Frog eat frog: exploring variables influencing anurophagy

    PubMed Central

    Vimercati, Giovanni; de Villiers, F. André; Mokhatla, Mohlamatsane M.; Davies, Sarah J.; Edwards, Shelley; Altwegg, Res

    2015-01-01

    Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species. PMID:26336644

  2. Meat-eating by a wild Bornean orang-utan (Pongo pygmaeus).

    PubMed

    Buckley, Benjamin J W; Dench, Rosalie J; Morrogh-Bernard, Helen C; Bustani, Unyil; Chivers, David J

    2015-10-01

    We present the first evidence for consumption of meat by a wild Bornean orang-utan (Pongo pygmaeus). Meat-eating has been reported in Sumatran orang-utans, specifically the hunting and consumption of slow lorises (Nycticebus coucang), but loris-hunting behaviour has not been observed in the Bornean species and meat of any species is essentially absent from their diet, with only two anecdotal reports of vertebrate meat consumption prior to this current finding in over 40 years of study. In August 2012 an unhabituated adult flanged male orang-utan was observed eating an adult horse-tailed squirrel (Sundasciurus hippurus) carcass in the Sabangau peat-swamp forest, Central Kalimantan. We suspect this to be a case of scavenging, never reported previously in a Bornean orang-utan. PMID:26298471

  3. Endocrinological correlates of male bimaturism in wild Bornean orangutans.

    PubMed

    Marty, Pascal R; van Noordwijk, Maria A; Heistermann, Michael; Willems, Erik P; Dunkel, Lynda P; Cadilek, Manuela; Agil, Muhammad; Weingrill, Tony

    2015-11-01

    Among primates, orangutans are unique in having pronounced male bimaturism leading to two fully adult morphs that differ in both physical appearance and behavior. While unflanged males have a female-like appearance, flanged males have the full suite of secondary sexual characteristics, including cheek flanges and a large throat sac. So far, hormonal correlates of arrested development in unflanged males and the expression of secondary sexual characteristics in flanged males have only been studied in zoo-housed individuals. In this study, we investigated fecal androgen and glucocorticoid metabolites as hormonal correlates of male bimaturism in 17 wild adult Bornean orangutans (Pongo pygmaeus) in Central Kalimantan, Indonesia. We predicted and found higher androgen levels in flanged males compared to unflanged males, probably due to ongoing strong competition among flanged males who meet too infrequently to establish a clear linear dominance hierarchy. Furthermore, we found no difference in fecal glucocorticoid metabolite concentrations between flanged and unflanged males, indicating that social stress is unlikely to explain arrested development in unflanged wild orangutans. The only actively developing male in our study showed significantly higher androgen levels during the period of development than later as a fully flanged male. This supports earlier findings from zoo studies that elevated androgen levels are associated with the development of secondary sexual characteristics. PMID:26235914

  4. Bornean orangutans on the brink of protein bankruptcy.

    PubMed

    Vogel, Erin R; Knott, Cheryl D; Crowley, Brooke E; Blakely, Melissa D; Larsen, Michael D; Dominy, Nathaniel J

    2012-06-23

    Protein is a limiting resource that is essential to the growth, maintenance and reproduction of tropical frugivores, yet few studies have examined how wild animals maintain protein balance. During chronic periods of fruit scarcity, Bornean orangutans (Pongo pygmaeus) often catabolize their own fat reserves despite unusually low metabolic requirements. Such energy deficits suggest a marginal existence, and raise the possibility that orangutans also endure periods of negative protein balance. To test this hypothesis, we conducted the first study of protein cycling in a wild primate. Our five year analysis of urinary metabolites revealed evidence of protein recycling when fruit was scarce. During these periods, orangutans consumed more leaves and bark, proteinaceous but tough foods that yielded a mean daily intake of 1.4 g protein kg(-1) metabolic mass. Such an amount is inadequate for humans and one-tenth the intake of mountain gorillas, but sufficient to avert, perhaps narrowly, a severe protein deficit. Our findings highlight the functional and adaptive value of traits that maximize protein assimilation during periods of ecological exigency. PMID:22171019

  5. Yet More Frogs

    ERIC Educational Resources Information Center

    Shutler, Paul M. E.

    2011-01-01

    Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical…

  6. Endemic Asian chytrid strain infection in threatened and endemic anurans of the Northern Western Ghats, India.

    PubMed

    Dahanukar, Neelesh; Krutha, Keerthi; Paingankar, Mandar S; Padhye, Anand D; Modak, Nikhil; Molur, Sanjay

    2013-01-01

    The Western Ghats of India harbors a rich diversity of amphibians with more than 77% species endemic to this region. At least 42% of the endemic species are threatened due to several anthropogenic stressors. However, information on amphibian diseases and their impacts on amphibian populations in this region are scarce. We report the occurrence of Batrachochytridium dendrobatidis (Bd), an epidermal aquatic fungal pathogen that causes chytridiomycosis in amphibians, from the Western Ghats. In the current study we detected the occurrence of a native Asian Bd strain from three endemic and threatened species of anurans, Bombay Night Frog Nyctibatrachus humayuni, Leith's Leaping Frog Indirana leithii and Bombay Bubble Nest Frog Raorchestes bombayensis, for the first time from the northern Western Ghats of India based on diagnostic nested PCR, quantitative PCR, DNA sequencing and histopathology. While, the Bd infected I. leithii and R. bombayensis did not show any external symptoms, N. humayuni showed lesions on the skin, browning of skin and sloughing. Sequencing of Bd 5.8S ribosomal RNA gene, and the ITS1 and ITS2 regions, revealed that the current Bd strain is related to a haplotype endemic to Asia. Our findings confirm the presence of Bd in northern Western Ghats and the affected amphibians may or may not show detectable clinical symptoms. We suggest that the significance of diseases as potential threat to amphibian populations of the Western Ghats needs to be highlighted from the conservation point of view. PMID:24147018

  7. Endemic Asian Chytrid Strain Infection in Threatened and Endemic Anurans of the Northern Western Ghats, India

    PubMed Central

    Dahanukar, Neelesh; Krutha, Keerthi; Paingankar, Mandar S.; Padhye, Anand D.; Modak, Nikhil; Molur, Sanjay

    2013-01-01

    The Western Ghats of India harbors a rich diversity of amphibians with more than 77% species endemic to this region. At least 42% of the endemic species are threatened due to several anthropogenic stressors. However, information on amphibian diseases and their impacts on amphibian populations in this region are scarce. We report the occurrence of Batrachochytridium dendrobatidis (Bd), an epidermal aquatic fungal pathogen that causes chytridiomycosis in amphibians, from the Western Ghats. In the current study we detected the occurrence of a native Asian Bd strain from three endemic and threatened species of anurans, Bombay Night Frog Nyctibatrachus humayuni, Leith's Leaping Frog Indirana leithii and Bombay Bubble Nest Frog Raorchestes bombayensis, for the first time from the northern Western Ghats of India based on diagnostic nested PCR, quantitative PCR, DNA sequencing and histopathology. While, the Bd infected I. leithii and R. bombayensis did not show any external symptoms, N. humayuni showed lesions on the skin, browning of skin and sloughing. Sequencing of Bd 5.8S ribosomal RNA gene, and the ITS1 and ITS2 regions, revealed that the current Bd strain is related to a haplotype endemic to Asia. Our findings confirm the presence of Bd in northern Western Ghats and the affected amphibians may or may not show detectable clinical symptoms. We suggest that the significance of diseases as potential threat to amphibian populations of the Western Ghats needs to be highlighted from the conservation point of view. PMID:24147018

  8. A Novel Reproductive Mode in Frogs: A New Species of Fanged Frog with Internal Fertilization and Birth of Tadpoles

    PubMed Central

    Iskandar, Djoko T.; Evans, Ben J.; McGuire, Jimmy A.

    2014-01-01

    We describe a new species of fanged frog (Limnonectes larvaepartus) that is unique among anurans in having both internal fertilization and birth of tadpoles. The new species is endemic to Sulawesi Island, Indonesia. This is the fourth valid species of Limnonectes described from Sulawesi despite that the radiation includes at least 15 species and possibly many more. Fewer than a dozen of the 6455 species of frogs in the world are known to have internal fertilization, and of these, all but the new species either deposit fertilized eggs or give birth to froglets. PMID:25551466

  9. First report of Lividin and Spinulosain peptides from the skin secretion of an Indian frog.

    PubMed

    Vineeth Kumar, Thundiparampil V; Gopal, Shyla; George, Sanil

    2016-03-01

    Here, we report two novel peptides identified from the skin secretion, having homologies to Lividin and Spinulosain, of an endemic frog, Hydrophylax bahuvistara, of Western Ghats. This is the first report of these peptides from Indian frogs and first identification of Lividin from the Hydrophylax genus. Both peptides exhibited weak antimicrobial activity but very low haemolytic activity. The problems of naming amphibian host defense peptides (HDPs) are also discussed. PMID:26960362

  10. Jan Swammerdam's frogs

    PubMed Central

    Sleigh, Charlotte

    2012-01-01

    Having discussed insect metamorphosis at length, Jan Swammerdam's Bybel der Natuure (1679/1737) reached its climax with a substantial description of the generation and muscular activity of frogs. This paper explores the rhetorical role of frogs in Swammerdam's ‘great work’, showing how they were the Archimedean point from which he aimed to reorder all of creation—from insects to humans—within one glorious, God-ordained natural history and philosophy. Swammerdam linked insects to frogs through a demonstration that all underwent epigenesis; and frogs were then linked to humans through a demonstration of their identical muscular activity. The success of Swammerdam's strategy required a theological reconstruction of the frog, traditionally an ungodly creature, such that trustworthy knowledge could be obtained from its body. Perhaps surprisingly, this act of theological cleansing is shown to be somewhat prefigured in the distinctly non-experimental natural history of Edward Topsell (1608). The paper also examines Swammerdam's interactions with the mystic Antoinette Bourignon, and his challenges in reconciling a spirituality of meletetics with a material epistemology in natural philosophy. Differences are revealed between the natural analogies given by Swammerdam in his published and unpublished writings, undermining to a certain extent the triumphal insect–frog–human rhetorical structure of the Bybel.

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

    PubMed

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

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity. PMID:26760304

  12. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi

    PubMed Central

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

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity. PMID:26760304

  13. Contribution of aboveground plant respiration to carbon cycling in a Bornean tropical rainforet

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Tanaka, Kenzo; Ichie, Tomoaki; Kume, Tomonori; Matsumoto, Kazuho; Ohashi, Mizue; Kumagai, Tomo'omi

    2014-05-01

    Bornean tropical rainforests have a different characteristic from Amazonian tropical rainforests, that is, larger aboveground biomass caused by higher stand density of large trees. Larger biomass may cause different carbon cycling and allocation pattern. However, there are fewer studies on carbon allocation and each component in Bornean tropical rainforests, especially for aboveground plant respiration, compared to Amazonian forests. In this study, we measured woody tissue respiration and leaf respiration, and estimated those in ecosystem scale in a Bornean tropical rainforest. Then, we examined carbon allocation using the data of soil respiration and aboveground net primary production obtained from our previous studies. Woody tissue respiration rate was positively correlated with diameter at breast height (dbh) and stem growth rate. Using the relationships and biomass data, we estimated woody tissue respiration in ecosystem scale though methods of scaling resulted in different estimates values (4.52 - 9.33 MgC ha-1 yr-1). Woody tissue respiration based on surface area (8.88 MgC ha-1 yr-1) was larger than those in Amazon because of large aboveground biomass (563.0 Mg ha-1). Leaf respiration rate was positively correlated with height. Using the relationship and leaf area density data at each 5-m height, leaf respiration in ecosystem scale was estimated (9.46 MgC ha-1 yr-1), which was similar to those in Amazon because of comparable LAI (5.8 m2 m-2). Gross primary production estimated from biometric measurements (44.81 MgC ha-1 yr-1) was much higher than those in Amazon, and more carbon was allocated to woody tissue respiration and total belowground carbon flux. Large tree with dbh > 60cm accounted for about half of aboveground biomass and aboveground biomass increment. Soil respiration was also related to position of large trees, resulting in high soil respiration rate in this study site. Photosynthesis ability of top canopy for large trees was high and leaves for

  14. It's a Frog's Life

    ERIC Educational Resources Information Center

    Coffey, Audrey L.; Sterling, Donna R.

    2003-01-01

    When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats. (Contains 1 resource.)

  15. Coming down from the trees: Is terrestrial activity in Bornean orangutans natural or disturbance driven?

    PubMed Central

    Ancrenaz, Marc; Sollmann, Rahel; Meijaard, Erik; Hearn, Andrew J.; Ross, Joanna; Samejima, Hiromitsu; Loken, Brent; Cheyne, Susan M.; Stark, Danica J.; Gardner, Penny C.; Goossens, Benoit; Mohamed, Azlan; Bohm, Torsten; Matsuda, Ikki; Nakabayasi, Miyabi; Lee, Shan Khee; Bernard, Henry; Brodie, Jedediah; Wich, Serge; Fredriksson, Gabriella; Hanya, Goro; Harrison, Mark E.; Kanamori, Tomoko; Kretzschmar, Petra; Macdonald, David W.; Riger, Peter; Spehar, Stephanie; Ambu, Laurentius N.; Wilting, Andreas

    2014-01-01

    The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated. PMID:24526001

  16. Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?

    PubMed

    Ancrenaz, Marc; Sollmann, Rahel; Meijaard, Erik; Hearn, Andrew J; Ross, Joanna; Samejima, Hiromitsu; Loken, Brent; Cheyne, Susan M; Stark, Danica J; Gardner, Penny C; Goossens, Benoit; Mohamed, Azlan; Bohm, Torsten; Matsuda, Ikki; Nakabayasi, Miyabi; Lee, Shan Khee; Bernard, Henry; Brodie, Jedediah; Wich, Serge; Fredriksson, Gabriella; Hanya, Goro; Harrison, Mark E; Kanamori, Tomoko; Kretzschmar, Petra; Macdonald, David W; Riger, Peter; Spehar, Stephanie; Ambu, Laurentius N; Wilting, Andreas

    2014-01-01

    The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated. PMID:24526001

  17. Ultrasonic communication in frogs.

    PubMed

    Feng, Albert S; Narins, Peter M; Xu, Chun-He; Lin, Wen-Yu; Yu, Zu-Lin; Qiu, Qiang; Xu, Zhi-Min; Shen, Jun-Xian

    2006-03-16

    Among vertebrates, only microchiropteran bats, cetaceans and some rodents are known to produce and detect ultrasounds (frequencies greater than 20 kHz) for the purpose of communication and/or echolocation, suggesting that this capacity might be restricted to mammals. Amphibians, reptiles and most birds generally have limited hearing capacity, with the ability to detect and produce sounds below approximately 12 kHz. Here we report evidence of ultrasonic communication in an amphibian, the concave-eared torrent frog (Amolops tormotus) from Huangshan Hot Springs, China. Males of A. tormotus produce diverse bird-like melodic calls with pronounced frequency modulations that often contain spectral energy in the ultrasonic range. To determine whether A. tormotus communicates using ultrasound to avoid masking by the wideband background noise of local fast-flowing streams, or whether the ultrasound is simply a by-product of the sound-production mechanism, we conducted acoustic playback experiments in the frogs' natural habitat. We found that the audible as well as the ultrasonic components of an A. tormotus call can evoke male vocal responses. Electrophysiological recordings from the auditory midbrain confirmed the ultrasonic hearing capacity of these frogs and that of a sympatric species facing similar environmental constraints. This extraordinary upward extension into the ultrasonic range of both the harmonic content of the advertisement calls and the frog's hearing sensitivity is likely to have co-evolved in response to the intense, predominantly low-frequency ambient noise from local streams. Because amphibians are a distinct evolutionary lineage from microchiropterans and cetaceans (which have evolved ultrasonic hearing to minimize congestion in the frequency bands used for sound communication and to increase hunting efficacy in darkness), ultrasonic perception in these animals represents a new example of independent evolution. PMID:16541072

  18. Teams Explore the Whole Frog

    ERIC Educational Resources Information Center

    Cessna, Clair E.

    1973-01-01

    Describes the content and organization of a laboratory session in which student teams work on the organs, tissues, and parasites of a pithed frog. The procedure maximizes participation by every student, makes possible the fullest use of each frog, and permits a rather broad study in a limited time. (JR)

  19. Mosquito repellents in frog skin

    PubMed Central

    Williams, C.R; Smith, B.P.C; Best, S.M; Tyler, M.J

    2006-01-01

    The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

  20. Home Range and Ranging Behaviour of Bornean Elephant (Elephas maximus borneensis) Females

    PubMed Central

    Alfred, Raymond; Ahmad, Abd Hamid; Payne, Junaidi; Williams, Christy; Ambu, Laurentius Nayan; How, Phua Mui; Goossens, Benoit

    2012-01-01

    Background Home range is defined as the extent and location of the area covered annually by a wild animal in its natural habitat. Studies of African and Indian elephants in landscapes of largely open habitats have indicated that the sizes of the home range are determined not only by the food supplies and seasonal changes, but also by numerous other factors including availability of water sources, habitat loss and the existence of man-made barriers. The home range size for the Bornean elephant had never been investigated before. Methodology/Principal Findings The first satellite tracking program to investigate the movement of wild Bornean elephants in Sabah was initiated in 2005. Five adult female elephants were immobilized and neck collars were fitted with tracking devices. The sizes of their home range and movement patterns were determined using location data gathered from a satellite tracking system and analyzed by using the Minimum Convex Polygon and Harmonic Mean methods. Home range size was estimated to be 250 to 400 km2 in a non-fragmented forest and 600 km2 in a fragmented forest. The ranging behavior was influenced by the size of the natural forest habitat and the availability of permanent water sources. The movement pattern was influenced by human disturbance and the need to move from one feeding site to another. Conclusions/Significance Home range and movement rate were influenced by the degree of habitat fragmentation. Once habitat was cleared or converted, the availability of food plants and water sources were reduced, forcing the elephants to travel to adjacent forest areas. Therefore movement rate in fragmented forest was higher than in the non-fragmented forest. Finally, in fragmented habitat human and elephant conflict occurrences were likely to be higher, due to increased movement bringing elephants into contact more often with humans. PMID:22347469

  1. A review of Bornean Micronectidae (Hemiptera, Heteroptera, Nepomorpha) with descriptions of two new species from Sabah, Malaysia1

    PubMed Central

    Chen, Ping-ping; Nieser, Nico; Lapidin, Johnny

    2015-01-01

    Abstract Previous research of Bornean Micronectidae Jaczewski, 1924 (pygmy water boatmen) is summarized based on the data from the literature and recent work. All the Bornean micronectids belong to the genus Micronecta Kirkaldy, 1897. Descriptions or redescriptions and a key to the eight species, which have so far been found in Borneo are presented, namely Micronecta decorata Lundblad, 1933, Micronecta ludibunda Breddin, 1905, Micronecta liewi sp. n., Micronecta lakimi sp. n., Micronecta lumutensis Chen, Nieser & Lansbury, 2008, Micronecta skutalis Nieser & Chen, 1999, Micronecta kymatista Nieser & Chen, 1999) and Micronecta quadristrigata Breddin, 1905. The synonyms are indicated under each species. To facilitate identification, illustrations and habitus photos are provided. The faunistic components of Micronectidae in Borneo are discussed from a zoogeographic point of view. PMID:25987878

  2. Why do orangutans leave the trees? Terrestrial behavior among wild Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan, Central Kalimantan.

    PubMed

    Ashbury, Alison M; Posa, Mary Rose C; Dunkel, Lynda P; Spillmann, Brigitte; Atmoko, S Suci Utami; van Schaik, Carel P; van Noordwijk, Maria A

    2015-11-01

    Orangutans (genus Pongo) are the largest arboreal mammals, but Bornean orangutans (P. pygmaeus spp.) also spend time on the ground. Here, we investigate ground use among orangutans using 32,000 hr of direct focal animal observations from a well-habituated wild population of Bornean orangutans (P. p. wurmbii) living in a closed-canopy swamp forest at Tuanan, Central Kalimantan, Indonesia. Ground use did not change with increasing observation time of well-habituated individuals, suggesting it was not an artifact of observer presence. Flanged males spent the most time on the ground (ca. 5% of active time), weaned immatures the least (around 1%). Females and immatures descended mainly to feed, especially on termites, whereas flanged males traveled more while on the ground. Flanged males may travel more inconspicuously, and perhaps also faster, when moving on the ground. In addition, orangutans engaged in ground-specific behavior, including drinking from and bathing in swamp pools. Supplementary records from 20 ground-level camera traps, totaling 3986 trap days, confirmed the observed age-sex biases in ground use at Tuanan. We conclude that ground use is a natural part of the Bornean orangutan behavioral repertoire, however it remains unclear to what extent food scarcity and canopy structure explain population differences in ground use. PMID:26317698

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

    PubMed

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

    2015-10-01

    The red-eyed tree frog (Agalychnis callidryas) is endemic to the rainforests of Central America. During the night, it hunts for insects in the treetops whereas at daytime, the frogs rest under leaves. In the present study we determined the relative visual sensitivity spectrum of this nocturnal frog species by ERG recordings in both the dark- and light-adapted state. In both the scotopic- and photopic-sensitivity curve, we found only minor individual variations among the tested individuals. The sensitivity maximum of the scotopic curve was determined at 500 nm, which matches the absorption properties of the RH1-visual pigment expressed in the red rods of frogs. The sensitivity maximum of the photopic curve was found at 545 nm which is close to the absorption maximum of the LWS pigment type expressed in most cones of the frog retina. The threshold curves determined by ERG recordings here reveal no unusual features in the sensitivity spectrum of the red-eyed tree frog that could be interpreted as adaptations for its strictly nocturnal life style. PMID:26184717

  4. Landscape resistance to frog movements

    USGS Publications Warehouse

    Mazerolle, M.J.; Desrochers, A.

    2005-01-01

    An animal's capacity to recolonize a patch depends on at least two components: its ability to detect the patch and its ability to reach it. However, the disruption of such processes by anthropic disturbances could explain low animal abundance patterns observed by many investigators in certain landscapes. Through field experiments, we compared the orientation and homing success of northern green frogs (Rana clamitans melanota Rafinesque, 1820) and northern leopard frogs (Rana pipiens Schreber, 1782) translocated across disturbed or undisturbed surfaces. We also monitored the path selected by individuals when presented with a choice between a short distance over a disturbed surface and a longer, undisturbed route. Finally, we measured the water loss and behaviour of frogs on substrates resulting from anthropogenic disturbances and a control. When presented with a choice, 72% of the frogs avoided disturbed surfaces. Although able to orient towards the pond of capture when translocated on disturbed surfaces, frogs had a lower probability of homing successfully to the pond than when translocated at a similar distance on an undisturbed surface. Frogs lost the most water on substrates associated with disturbance and in the absence of cover. Our data illustrate that anthropically disturbed areas devoid of cover, such as mined peatlands and agricultural fields, disrupt the ability of frogs to reach habitat patches and are likely explanations to their reduced abundance patterns in such environments. ?? 2005 NRC Canada.

  5. Leopard frog and wood frog reproduction in Colorado and Wyoming

    USGS Publications Warehouse

    Corn, Paul Stephen; Livo, Lauren J.

    1989-01-01

    Between 1978 and 1988, we recorded reproductive information from populations of ranid frogs in Colorado and Wyoming. Egg masses from five plains and montane populations of northern leopard frogs (Rana pipiens) contained 645-6272 eggs (x̄ = 3045, N = 68 egg masses). In two montane populations of wood frogs (Rana sylvatica) numbers of eggs per egg mass varied from 711-1248 (x̄ = 876, N = 15) and probably were equal to total clutch size. Mean hatching success was 90% in egg masses from one R. sylvatica population and ranged from 70% to 99% in R. pipiens egg masses. Rana pipiens egg masses from one location were assigned to three overlapping size distributions, which we believe reflects the underlying age structure of female frogs.

  6. Index of endemicity

    PubMed Central

    Swaroop, Satya

    1957-01-01

    The author discusses the difficulties involved in defining the term “endemicity”, and suggests a new approach to the problem—namely, the establishment of indices of endemicity, based on such data as are usually collected by national health administrations (mortality and morbidity rates, spleen-rates, case incidence in seaports, etc.). Examples are given of the calculation of the endemicity index for a number of diseases from different types of data obtained from various countries. An important advantage of the endemicity index is that it provides an easy means of studying the geographical pattern of endemic foci of disease. PMID:13479767

  7. Developmental aspects of the direct-developing frog Adelophryne maranguapensis.

    PubMed

    de Lima, Ana V P; Reis, Alice H; Amado, Nathália G; Cassiano-Lima, Daniel; Borges-Nojosa, Diva M; Oriá, Reinaldo B; Abreu, José G

    2016-05-01

    Direct development in amphibians is characterized by the loss of aquatic breeding. The anuran Adelophryne maranguapensis is one example of a species with direct development, and it is endemic to the state of Ceará, Brazil. Detailed morphological features of A. maranguapensis embryos and the stages of sequential development have not been described before. Here, we analyzed all available genetic sequence tags in A. maranguapensis (tyr exon 1, pomc and rag1) and compared them with sequences from other species of Adelophryne frogs. We describe the A. maranguapensis reproductive tract and embryonic body development, with a focus on the limbs, tail, ciliated cells of the skin, and the egg tooth, which were analyzed using scanning electron microscopy. Histological analyses revealed ovaries containing oocytes surrounded by follicular cells, displaying large nuclei with nucleoli inside. Early in development, the body is unpigmented, and the neural tube forms dorsally to the yolk vesicle, typical of a direct-developing frog embryo. The hindlimbs develop earlier than the forelimbs. Ciliated cells are abundant during the early stages of skin development and are less common during later stages. The egg tooth appears in the later stages and develops as a keratinized microridge structure. The developmental profile of A. maranguapensis presented here will contribute to our understanding of the direct-development model and may help preserve this endangered native Brazilian frog. genesis 54:257-271, 2016. © 2016 Wiley Periodicals, Inc. PMID:26953634

  8. A Comparison of V-Frog[C] to Physical Frog Dissection

    ERIC Educational Resources Information Center

    Lalley, James P.; Piotrowski, Phillip S.; Battaglia, Barbara; Brophy, Keith; Chugh, Kevin

    2010-01-01

    The purpose of the present study was to examine and compare the effectiveness of virtual frog dissection using V-Frog[C] and physical frog dissection on learning, retention, and affect. Subjects were secondary students enrolled in year-long life science classes in a suburban high school (N=102). Virtual dissections were done with V-Frog[C], a…

  9. To Be or Not to Be...a Frog: The Frog Prince and Shifting Paradigms.

    ERIC Educational Resources Information Center

    Crane, Lisa Marie

    1997-01-01

    Discusses three modern variations of the classic "Frog Prince" folk tale: "Pondlarker" (Fred Gwynne); "The Frog Prince Continued" (Jon Scieszka); and "The Prince of the Pond" (Donna Jo Napoli). Notes that these variants create a world in which frogs can have values, wisdom, and emotion, and in which frogs can influence the ways of humanity. (RS)

  10. The first endemic West African vertebrate family – a new anuran family highlighting the uniqueness of the Upper Guinean biodiversity hotspot

    PubMed Central

    2014-01-01

    Background Higher-level systematics in amphibians is relatively stable. However, recent phylogenetic studies of African torrent-frogs have uncovered high divergence in these phenotypically and ecologically similar frogs, in particular between West African torrent-frogs versus Central (Petropedetes) and East African (Arthroleptides and Ericabatrachus) lineages. Because of the considerable molecular divergence, and external morphology of the single West African torrent-frog species a new genus was erected (Odontobatrachus). In this study we aim to clarify the systematic position of West African torrent-frogs (Odontobatrachus). We determine the relationships of torrent-frogs using a multi-locus, nuclear and mitochondrial, dataset and include genera of all African and Asian ranoid families. Using micro-tomographic scanning we examine osteology and external morphological features of West African torrent-frogs to compare them with other ranoids. Results Our analyses reveal Petropedetidae (Arthroleptides, Ericabatrachus, Petropedetes) as the sister taxon of the Pyxicephalidae. The phylogenetic position of Odontobatrachus is clearly outside Petropedetidae, and not closely related to any other ranoid family. According to our time-tree estimation Odontobatrachus has been separated from other frog lineages since the Cretaceous (90.1 Ma; confidence interval: 84.2-97.1 Ma). Along with this molecular evidence, osteological and external diagnostic characters recognize West African torrent-frogs as distinct from other ranoids and provide strong support for the necessity of the recognition of a new family of frogs. This is the only endemic vertebrate family occurring in the Upper Guinea biodiversity hotspot. Conclusion Based on molecular and morphological distinctiveness, the West African torrent-frog Odontobatrachus natator is allocated to a newly described anuran family. The discovery of an endemic vertebrate family in West Africa highlights the Upper Guinean forests as an

  11. The Classroom Animal: The Leopard Frog.

    ERIC Educational Resources Information Center

    Science and Children, 1985

    1985-01-01

    Describes the natural history of the leopard frog and factors which make it appropriate for short-term study in the classroom. Information on the frog's habits, life cycle, housing, care, and health is included. (DH)

  12. Co-occurrence patterns of Bornean vertebrates suggest competitive exclusion is strongest among distantly related species.

    PubMed

    Beaudrot, Lydia; Struebig, Matthew J; Meijaard, Erik; van Balen, S; Husson, Simon; Marshall, Andrew J

    2013-11-01

    Assessing the importance of deterministic processes in structuring ecological communities is a central focus of community ecology. Typically, community ecologists study a single taxonomic group, which precludes detection of potentially important biotic interactions between distantly related species, and inherently assumes competition is strongest between closely related species. We examined distribution patterns of vertebrate species across the island of Borneo in Southeast Asia to assess the extent to which inter-specific competition may have shaped ecological communities on the island and whether the intensity of inter-specific competition in present-day communities varies as a function of evolutionary relatedness. We investigated the relative extent of competition within and between species of primates, birds, bats and squirrels using species presence-absence and attribute data compiled for 21 forested sites across Borneo. We calculated for each species pair the checkerboard unit value (CU), a statistic that is often interpreted as indicating the importance of interspecific competition. The percentage of species pairs with significant CUs was lowest in within-taxon comparisons. Moreover, for invertebrate-eating species the percentage of significantly checkerboarded species pairs was highest in comparisons between primates and other taxa, particularly birds and squirrels. Our results are consistent with the interpretation that competitive interactions between distantly related species may have shaped the distribution of species and thus the composition of Bornean vertebrate communities. This research highlights the importance of taking into account the broad mammalian and avian communities in which species occur for understanding the factors that structure biodiversity. PMID:23736548

  13. Estimate of fine root production including the impact of decomposed roots in a Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Khoon Koh, Lip; Kume, Tomonori; Makita, Naoki; Matsumoto, Kazuho; Ohashi, Mizue

    2016-04-01

    Considerable carbon is allocated belowground and used for respiration and production of roots. It is reported that approximately 40 % of GPP is allocated belowground in a Bornean tropical rainforest, which is much higher than those in Neotropical rainforests. This may be caused by high root production in this forest. Ingrowth core is a popular method for estimating fine root production, but recent study by Osawa et al. (2012) showed potential underestimates of this method because of the lack of consideration of the impact of decomposed roots. It is important to estimate fine root production with consideration for the decomposed roots, especially in tropics where decomposition rate is higher than other regions. Therefore, objective of this study is to estimate fine root production with consideration of decomposed roots using ingrowth cores and root litter-bag in the tropical rainforest. The study was conducted in Lambir Hills National Park in Borneo. Ingrowth cores and litter bags for fine roots were buried in March 2013. Eighteen ingrowth cores and 27 litter bags were collected in May, September 2013, March 2014 and March 2015, respectively. Fine root production was comparable to aboveground biomass increment and litterfall amount, and accounted only 10% of GPP in this study site, suggesting most of the carbon allocated to belowground might be used for other purposes. Fine root production was comparable to those in Neotropics. Decomposed roots accounted for 18% of fine root production. This result suggests that no consideration of decomposed fine roots may cause underestimate of fine root production.

  14. The influence of ambient noise on maternal behavior in a Bornean sun bear (Helarctos malayanus euryspilus).

    PubMed

    Owen, Megan A; Hall, Suzanne; Bryant, Lisa; Swaisgood, Ronald R

    2014-01-01

    Anthropogenic noise has become a pervasive feature of both marine and terrestrial habitats worldwide. While a comprehensive understanding of the biologically significant impacts of noise on wildlife is lacking, concerns regarding its influence persist. Noise is also a common feature in the zoological setting, and much can be learned regarding the species-typical response to ambient noise by studying animals in captivity. Here we correlate behavioral and vocal patterns in a Bornean sun bear (Helarctos malayanus euryspilus) mother and cub with ambient noise levels during the 6-month post-partum period. We hypothesized that loud ambient noise would be correlated with changes in behavior, and predicted that noise would be negatively correlated with maternal care behavior, potentially masking cub vocalizations or providing a distraction to the mother. Contrary to expectation, we found that the mother spent significantly more time attending to her cub (P=0.03) on loud days. We also found that she tended to spend less time feeding (P=0.08); however her time spent resting was not affected. The cub was approximately twice as vocal on loud days, although these results were not statistically significant (humming: P=0.10; squawks/cries: P=0.14). Taken together, these results suggest that the behavioral response to ambient noise may have potential energetic costs, and as a result efforts should be made to reduce ambient noise exposure during the post-partum period. PMID:24357100

  15. Spargana infection of frogs in Malaysia.

    PubMed

    Mastura, A B; Ambu, S; Hasnah, O; Rosli, R

    1996-03-01

    Frogs caught from two States (Selangor and Langkawi) in Malaysia were examined for spargana of Spirometra sp. Infected frogs usually show no marks of infection but some had swelling and bleeding at the infection site. The size and weight of the infected frogs did not correlate with the infection status. The infection status in relation to human health is discussed. PMID:9031400

  16. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches,...

  17. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches,...

  18. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches,...

  19. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches,...

  20. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches,...

  1. What's the Difference between Frogs and Toads?

    ERIC Educational Resources Information Center

    Brown, Herrick

    2004-01-01

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

  2. FROG: Time-series analysis

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair

    2014-06-01

    FROG performs time series analysis and display. It provides a simple user interface for astronomers wanting to do time-domain astrophysics but still offers the powerful features found in packages such as PERIOD (ascl:1406.005). FROG includes a number of tools for manipulation of time series. Among other things, the user can combine individual time series, detrend series (multiple methods) and perform basic arithmetic functions. The data can also be exported directly into the TOPCAT (ascl:1101.010) application for further manipulation if needed.

  3. Effective population size dynamics and the demographic collapse of Bornean orang-utans.

    PubMed

    Sharma, Reeta; Arora, Natasha; Goossens, Benoit; Nater, Alexander; Morf, Nadja; Salmona, Jordi; Bruford, Michael W; Van Schaik, Carel P; Krützen, Michael; Chikhi, Lounès

    2012-01-01

    Bornean orang-utans experienced a major demographic decline and local extirpations during the Pleistocene and Holocene due to climate change, the arrival of modern humans, of farmers and recent commercially-driven habitat loss and fragmentation. The recent loss of habitat and its dramatic fragmentation has affected the patterns of genetic variability and differentiation among the remaining populations and increased the extinction risk of the most isolated ones. However, the contribution of recent demographic events to such genetic patterns is still not fully clear. Indeed, it can be difficult to separate the effects of recent anthropogenic fragmentation from the genetic signature of prehistoric demographic events. Here, we investigated the genetic structure and population size dynamics of orang-utans from different sites. Altogether 126 individuals were analyzed and a full-likelihood Bayesian approach was applied. All sites exhibited clear signals of population decline. Population structure is known to generate spurious bottleneck signals and we found that it does indeed contribute to the signals observed. However, population structure alone does not easily explain the observed patterns. The dating of the population decline varied across sites but was always within the 200-2000 years period. This suggests that in some sites at least, orang-utan populations were affected by demographic events that started before the recent anthropogenic effects that occurred in Borneo. These results do not mean that the recent forest exploitation did not leave its genetic mark on orang-utans but suggests that the genetic pool of orang-utans is also impacted by more ancient events. While we cannot identify the main cause for this decline, our results suggests that the decline may be related to the arrival of the first farmers or climatic events, and that more theoretical work is needed to understand how multiple demographic events impact the genome of species and how we can assess

  4. EVALUATION OF DIAGNOSTIC ACCURACY OF THE COMPARATIVE TUBERCULIN SKIN TEST IN REHABILITANT BORNEAN ORANGUTANS (PONGO PYGMAEUS).

    PubMed

    Dench, Rosalie; Sulistyo, Fransiska; Fahroni, Agus; Philippa, Joost

    2015-12-01

    The tuberculin skin test (TST) has been the mainstay of tuberculosis (TB) testing in primates for decades, but its interpretation in orangutans (Pongo spp.) is challenging, because many animals react strongly, without evidence of infection with Mycobacterium tuberculosis complex. One explanation is cross-reactivity with environmental nontuberculous mycobacteria (NTM). The use of a comparative TST (CTST), comparing reactivity to avian (representing NTM) and bovine (representing tuberculous mycobacteria) tuberculins aids in distinguishing cross-reactivity due to sensitization by NTM from shared antigens. The specificity of the TST can be increased with the use of CTST. We considered three interpretations of the TST in rehabilitant Bornean orangutans ( Pongo pygmaeus ) using avian purified protein derivative (APPD; 25,000 IU/ml) and two concentrations of bovine purified protein derivative (BPPD; 100,000 and 32,500 IU/ml). The tests were evaluated for their ability to identify accurately seven orangutans previously diagnosed with and treated for TB from a group of presumed negative individuals (n = 288 and n = 161 for the two respective BPPD concentrations). BPPD at 32,500 IU/ml had poor diagnostic capacity, whereas BPPD at 100,000 IU/ml performed better. The BPPD-only interpretation had moderate sensitivity (57%) and poor specificity (40%) and accuracy (41%). The comparative interpretation at 72 hr had similar sensitivity (57%) but improved specificity (95%) and accuracy (94%). However, best results were obtained by a comparative interpretation incorporating the 48- and 72-hr scores, which had good sensitivity (86%), specificity (95%) and accuracy (95%). These data reinforce recommendations that a CTST be used in orangutans and support the use of APPD at 25,000 IU/ml and BPPD at 100,000 IU/ml. The highest score at each site from the 48- and 72-hr checks should be considered the result for that tuberculin. If the bovine result is greater than the avian result, the

  5. Effective Population Size Dynamics and the Demographic Collapse of Bornean Orang-Utans

    PubMed Central

    Goossens, Benoit; Nater, Alexander; Morf, Nadja; Salmona, Jordi; Bruford, Michael W.; Van Schaik, Carel P.; Krützen, Michael; Chikhi, Lounès

    2012-01-01

    Bornean orang-utans experienced a major demographic decline and local extirpations during the Pleistocene and Holocene due to climate change, the arrival of modern humans, of farmers and recent commercially-driven habitat loss and fragmentation. The recent loss of habitat and its dramatic fragmentation has affected the patterns of genetic variability and differentiation among the remaining populations and increased the extinction risk of the most isolated ones. However, the contribution of recent demographic events to such genetic patterns is still not fully clear. Indeed, it can be difficult to separate the effects of recent anthropogenic fragmentation from the genetic signature of prehistoric demographic events. Here, we investigated the genetic structure and population size dynamics of orang-utans from different sites. Altogether 126 individuals were analyzed and a full-likelihood Bayesian approach was applied. All sites exhibited clear signals of population decline. Population structure is known to generate spurious bottleneck signals and we found that it does indeed contribute to the signals observed. However, population structure alone does not easily explain the observed patterns. The dating of the population decline varied across sites but was always within the 200–2000 years period. This suggests that in some sites at least, orang-utan populations were affected by demographic events that started before the recent anthropogenic effects that occurred in Borneo. These results do not mean that the recent forest exploitation did not leave its genetic mark on orang-utans but suggests that the genetic pool of orang-utans is also impacted by more ancient events. While we cannot identify the main cause for this decline, our results suggests that the decline may be related to the arrival of the first farmers or climatic events, and that more theoretical work is needed to understand how multiple demographic events impact the genome of species and how we can assess

  6. Variation in developmental arrest among male orangutans: a comparison between a Sumatran and a Bornean population

    PubMed Central

    2013-01-01

    Introduction The presence of two sexually active male morphs with different reproductive tactics in a single species is rare among mammals. The most striking case of bimaturism among primates is exhibited by the orangutan (Pongo spp), in which one adult morph, the unflanged male, irreversibly develops into another one, the flanged form, but may remain arrested in the unflanged state for many years. However, it has been suggested that such arrest is less common among Bornean orangutans (Pongo pygmaeus) compared to Sumatrans (Pongo abelii). To investigate this possible inter-specific difference we compared both the number of developing males and the ratios of the two male morphs at two long-term study sites, Suaq Balimbing on Sumatra and Tuanan on Borneo. Results First, we observed a significantly greater number of flanged than unflanged males per month in the Tuanan study area, whereas the opposite pattern held at Suaq. Second, the same contrast held for the total number of identified individuals over the study, with more flanged than unflanged males at Tuanan and the opposite at Suaq. These differences were mainly due to transient males. For Tuanan, the identification results were confirmed by detailed genetic analyses. Finally, we recorded a higher proportion of unflanged males that became flanged during any given year at Tuanan than at Suaq. Conclusion These results show that developmental arrest is far more common at Suaq than at Tuanan. Preliminary comparisons suggest that this is a general contrast between the island taxa of orangutans and should help efforts to identify the function and proximate control of developmental arrest in orangutan males. PMID:23510027

  7. FROG - Fingerprinting Genomic Variation Ontology.

    PubMed

    Abinaya, E; Narang, Pankaj; Bhardwaj, Anshu

    2015-01-01

    Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies). FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog. PMID:26244889

  8. CARE AND FEEDING OF FROGS

    SciTech Connect

    Pan, Margaret; Chiang, Eugene

    2012-01-15

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

  9. Neglected and endemic zoonoses

    PubMed Central

    Maudlin, Ian; Eisler, Mark Charles; Welburn, Susan Christina

    2009-01-01

    Endemic zoonoses are found throughout the developing world, wherever people live in close proximity to their animals, affecting not only the health of poor people but often also their livelihoods through the health of their livestock. Unlike newly emerging zoonoses that attract the attention of the developed world, these endemic zoonoses are by comparison neglected. This is, in part, a consequence of under-reporting, resulting in underestimation of their global burden, which in turn artificially downgrades their importance in the eyes of administrators and funding agencies. The development of cheap and effective vaccines is no guarantee that these endemic diseases will be eliminated in the near future. However, simply increasing awareness about their causes and how they may be prevented—often with very simple technologies—could reduce the incidence of many endemic zoonoses. Sustainable control of zoonoses is reliant on surveillance, but, as with other public-sector animal health services, this is rarely implemented in the developing world, not least because of the lack of sufficiently cheap diagnostics. Public–private partnerships have already provided advocacy for human disease control and could be equally effective in addressing endemic zoonoses. PMID:19687045

  10. Ontogenetic Change of Signal Brightness in the Foot-Flagging Frog Species Staurois parvus and Staurois guttatus

    PubMed Central

    Stangel, Judith; Preininger, Doris; Sztatecsny, Marc; Hödl, Walter

    2015-01-01

    Adult individuals of several anuran species exhibit conspicuous visual displays during intraspecific communication. While signal properties in adults have been subject to an increasing number of studies, little is known about the variation of visual signals in juveniles and during ontogenetic changes. Foot-flagging signals of the Bornean frogs Staurois guttatus and S. parvus were observed in juveniles a few days after metamorphosis. We investigated color parameters of foot webbings and body coloration of individuals bred at the Vienna Zoo, and their relation to age and body size using spectrophotometry. Our results indicate that the brightness of foot webbings of S. guttatus and S. parvus increased with increasing age. Additionally, we compared the results with measurements of adult individuals from a population in Brunei and discuss possible differences related to diet and age as well as the habitat use of juveniles and adults. We suggest that the ontogenetic increase in foot-webbing brightness enhances visual conspicuousness and the signal-to-noise ratio of the visual signal with sexual maturity and potentially functions as cue to the age of the signaler. PMID:25983337

  11. Evidence for an intrinsic factor promoting landscape genetic divergence in Madagascan leaf-litter frogs

    PubMed Central

    Wollenberg Valero, Katharina C.

    2015-01-01

    The endemic Malagasy frog radiations are an ideal model system to study patterns and processes of speciation in amphibians. Large-scale diversity patterns of these frogs, together with other endemic animal radiations, led to the postulation of new and the application of known hypotheses of species diversification causing diversity patterns in this biodiversity hotspot. Both extrinsic and intrinsic factors have been studied in a comparative framework, with extrinsic factors usually being related to the physical environment (landscape, climate, river catchments, mountain chains), and intrinsic factors being clade-specific traits or constraints (reproduction, ecology, morphology, physiology). Despite some general patterns emerging from such large-scale comparative analyses, it became clear that the mechanism of diversification in Madagascar may vary among clades, and may be a multifactorial process. In this contribution, I test for intrinsic factors promoting population-level divergence within a clade of terrestrial, diurnal leaf-litter frogs (genus Gephyromantis) that has previously been shown to diversify according to extrinsic factors. Landscape genetic analyses of the microendemic species Gephyromantis enki and its widely distributed, larger sister species Gephyromantis boulengeri over a rugged landscape in the Ranomafana area shows that genetic variance of the smaller species cannot be explained by landscape resistance alone. Both topographic and riverine barriers are found to be important in generating this divergence. This case study yields additional evidence for the probable importance of body size in lineage diversification. PMID:26136766

  12. Susceptibility of the endangered frog Dendropsophus meridensis to the pathogenic fungus Batrachochytrium dendrobatidis.

    PubMed

    Villarroel, Leomar; García, Carmen Zulay; Nava-González, Francisco; Lampo, Margarita

    2013-11-25

    Chytridiomycosis is an emerging disease that has driven some amphibian species to extinction while leaving others apparently unharmed. Its causative agent, Batrachochytrium dendrobatidis (Bd), now persists endemically in many amphibian communities. Understanding host species response to Bd infection is critical for managing chytridiomycosis because the epidemiology of this disease is host-specific. Dendropsophus meridensis is an endangered hylid frog endemic to the Venezuelan Andes. This species is sympatric with the American bullfrog Lithobates catesbeianus, an introduced species known to act as a reservoir for Bd. High prevalence of infection and high zoospore burdens in wild populations of D. meridensis in the Venezuelan Andes suggested some tolerance for Bd. However, experimental exposure of post-metamorphic frogs resulted in 53% mortality, a value that represents a 14-fold increase in the odds of dying compared to control frogs. Repeated diagnostics using real-time polymerase chain reaction assays demonstrated that individuals that died accumulated a higher number of zoospores than those that survived, although this value was lower than the mean zoospore burdens observed in natural populations. Given the susceptibility of D. meridensis to a strain of Bd isolated from a nearby population of bullfrogs, we emphasize the need to limit the dispersion of this invasive species. PMID:24270025

  13. Endemic cretinism in Sicily.

    PubMed

    Squatrito, S; Delange, F; Trimarchi, F; Lisi, E; Vigneri, R

    1981-01-01

    This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 +/- 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins and urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis. PMID:7320434

  14. Endemic treponemal diseases.

    PubMed

    Marks, Michael; Solomon, Anthony W; Mabey, David C

    2014-10-01

    The endemic treponemal diseases, consisting of yaws, bejel (endemic syphilis) and pinta, are non-venereal infections closely related to syphilis, and are recognized by WHO as neglected tropical diseases (NTDs). Despite previous worldwide eradication efforts the prevalence of yaws has rebounded in recent years and the disease is now a major public health problem in 14 countries. Adequate data on the epidemiology of bejel and pinta is lacking. Each disease is restricted to a specific ecological niche but all predominantly affect poor, rural communities. As with venereal syphilis, the clinical manifestations of the endemic treponemal diseases are variable and can be broken down in to early stage and late stage disease. Current diagnostic techniques are unable to distinguish the different causative species but newer molecular techniques are now making this possible. Penicillin has long been considered the mainstay of treatment for the endemic treponemal diseases but the recent discovery that azithromycin is effective in the treatment of yaws has renewed interest in these most neglected of the NTDs, and raised hopes that global eradication may finally be possible. PMID:25157125

  15. Fat frogs, mobile genes: unexpected phylogeographic patterns for the ornate chorus frog (Pseudacris ornata).

    PubMed

    Degner, Jacob F; Silva, Diana M; Hether, Tyler D; Daza, Juan M; Hoffman, Eric A

    2010-06-01

    The southeastern coastal plain of the United States is a region marked by extraordinary phylogeographic congruence that is frequently attributed to the changing sea levels that occurred during the glacial-interglacial cycles of the Pleistocene epoch. A phylogeographic break corresponding to the Apalachicola River has been suggested for many species studied to date that are endemic to this region. Here, we used this pattern of phylogeographic congruence to develop and test explicit hypotheses about the genetic structure in the ornate chorus frog (Pseudacris ornata). Using 1299 bp of mtDNA sequence and seven nuclear microsatellite markers in 13 natural populations of P. ornata, we found three clades corresponding to geographically distinct regions; one spans the Apalachicola River (Southern Clade), one encompasses Georgia and South Carolina (Central Clade) and a third comprises more northerly individuals (Northern Clade). However, it does not appear that typical phylogeographic barriers demarcate these clades. Instead, isolation by distance across the range of the entire species explained the pattern of genetic variation that we observed. We propose that P. ornata was historically widespread in the southeastern United States, and that a balance between genetic drift and migration was the root of the genetic divergence among populations. Additionally, we investigated fine-scale patterns of genetic structure and found the spatial scale at which there was significant genetic structure varied among the regions studied. Furthermore, we discuss our results in light of other phylogeographic studies of southeastern coastal plain organisms and in relation to amphibian conservation and management. PMID:20497321

  16. Interactions between a wild Bornean orang-utan and a Philippine slow loris in a peat-swamp forest.

    PubMed

    Morrogh-Bernard, Helen C; Stitt, Jessica M; Yeen, Zeri; Nekaris, K A I; Cheyne, Susan M

    2014-07-01

    All documented orang-utan-loris interactions have been from Sumatra, where lorises were opportunistically preyed upon by orang-utans. In this paper, we describe two accounts of the Bornean orang-utan (Pongo pygmaeus wurmbii) interacting with the Philippine slow loris (Nycticebus menagensis). The interactions were by two adolescent female orang-utans. No attempts to catch the loris were observed on either occasion. Neither interaction was hostile. During the second observation, which was more detailed, we considered the behaviour to be play rather than aggression or attempted predation. Based upon the lack of interest from the adult females during these rare encounters, we propose that the behaviour represents play or non-aggressive exploration rather than predation. PMID:24781375

  17. Body mass of wild Bornean orangutans living in human-dominated landscapes: Implications for understanding their ecology and conservation.

    PubMed

    Rayadin, Yaya; Spehar, Stephanie N

    2015-06-01

    Body mass is a key determinant of a species' ecology, including locomotion, foraging strategies, and energetics. Accurate information on the body mass of wild primates allows us to develop explanatory models for relationships among body size, ecology, and behavior and is crucial for reconstructing the ecology and behavior of fossil primates and hominins. Information on body mass can also provide indirect information on health and can be an important tool for conservation in the context of increasingly widespread habitat disturbance. This study reports body mass data recorded for wild Northeast Bornean orangutans (Pongo pygmaeus morio) during relocation efforts in forestry and oil palm plantations in East Kalimantan, Indonesia. The average mass of flanged adult males (n = 12, 74 ± 9.78 kg) and adult females (n = 7, 35.29 ± 7.32 kg) from this study were 13.6% and 9% lower, respectively, than the only other published wild Bornean orangutan body mass measurements, but the range of weights for both males and females was larger for this study. This pattern could be due to sampling error, data collection differences, or the influence of habitat disturbance, specifically a lack of access to resources, on individual health. When necessary relocations present the opportunity, we encourage researchers to prioritize the collection of body size data for the purposes of understanding ecology but also as an indirect means of monitoring population viability. As primate habitat becomes increasingly fragmented and altered by humans such data will become critical to our ability to make informed conservation decisions. PMID:25682922

  18. Two Different High Throughput Sequencing Approaches Identify Thousands of De Novo Genomic Markers for the Genetically Depleted Bornean Elephant

    PubMed Central

    Sharma, Reeta; Goossens, Benoit; Kun-Rodrigues, Célia; Teixeira, Tatiana; Othman, Nurzhafarina; Boone, Jason Q.; Jue, Nathaniel K.; Obergfell, Craig; O'Neill, Rachel J.; Chikhi, Lounès

    2012-01-01

    High throughput sequencing technologies are being applied to an increasing number of model species with a high-quality reference genome. The application and analyses of whole-genome sequence data in non-model species with no prior genomic information are currently under way. Recent sequencing technologies provide new opportunities for gathering genomic data in natural populations, laying the empirical foundation for future research in the field of conservation and population genomics. Here we present the case study of the Bornean elephant, which is the most endangered subspecies of Asian elephant and exhibits very low genetic diversity. We used two different sequencing platforms, the Roche 454 FLX (shotgun) and Illumina, GAIIx (Restriction site associated DNA, RAD) to evaluate the feasibility of the two methodologies for the discovery of de novo markers (single nucleotide polymorphism, SNPs and microsatellites) using low coverage data. Approximately, 6,683 (shotgun) and 14,724 (RAD) SNPs were detected within our elephant sequence dataset. Genotyping of a representative sample of 194 SNPs resulted in a SNP validation rate of ∼ 83 to 94% and 17% of the loci were polymorphic with a low diversity (Ho = 0.057). Different numbers of microsatellites were identified through shotgun (27,226) and RAD (868) techniques. Out of all di-, tri-, and tetra-microsatellite loci, 1,706 loci had sufficient flanking regions (shotgun) while only 7 were found with RAD. All microsatellites were monomorphic in the Bornean but polymorphic in another elephant subspecies. Despite using different sample sizes, and the well known differences in the two platforms used regarding sequence length and throughput, the two approaches showed high validation rate. The approaches used here for marker development in a threatened species demonstrate the utility of high throughput sequencing technologies as a starting point for the development of genomic tools in a non-model species and in particular

  19. Coqui frogs persist with the deadly chytrid fungus despite a lack of defensive antimicrobial peptides.

    PubMed

    Rollins-Smith, Louise A; Reinert, Laura K; Burrowes, Patricia A

    2015-02-10

    The amphibian skin fungus Batrachochytrium dendrobatidis (Bd) occurs widely in Puerto Rico and is thought to be responsible for the apparent extinction of 3 species of endemic frogs in the genus Eleutherodactylus, known as coquis. To examine immune defenses which may protect surviving species, we induced secretion of skin peptides from adult common coqui frogs E. coqui collected from upland forests at El Yunque. By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we were unable to detect peptide signals suggestive of antimicrobial peptides, and enriched peptides showed no capacity to inhibit growth of Bd. Thus, it appears that E. coqui depend on other skin defenses to survive in the presence of this deadly fungus. PMID:25667340

  20. The Ups and Downs of Frogs.

    ERIC Educational Resources Information Center

    Greene, Janice Schnake; Tamme, Tina

    2001-01-01

    Presents a science activity in which students simulate increases and decreases in frog populations to get a better understanding of different environmental issues affecting animal populations. Includes simulations for both natural frog populations as well as populations affected by human activities. (YDS)

  1. Semi-automated identification of leopard frogs

    USGS Publications Warehouse

    Petrovska-Delacrétaz, Dijana; Edwards, Aaron; Chiasson, John; Chollet, Gérard; Pilliod, David S.

    2014-01-01

    Principal component analysis is used to implement a semi-automatic recognition system to identify recaptured northern leopard frogs (Lithobates pipiens). Results of both open set and closed set experiments are given. The presented algorithm is shown to provide accurate identification of 209 individual leopard frogs from a total set of 1386 images.

  2. Endemic skeletal fluorosis

    PubMed Central

    Teotia, M.; Teotia, S. P. S.; Kunwar, K. B.

    1971-01-01

    Endemic skeletal fluorosis is described in 6 children aged 11 or over. Four cases were crippled with severe deformities in the spine, hips, and knees. All showed positive phosphorus, magnesium, and nitrogen balances and excessively positive calcium balances. The skeletal x-rays, histology, and chemical composition of the bones revealed diagnostic changes in each case. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:5118057

  3. The Endemic Treponematoses

    PubMed Central

    Giacani, Lorenzo

    2014-01-01

    SUMMARY The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents. PMID:24396138

  4. The endemic treponematoses.

    PubMed

    Giacani, Lorenzo; Lukehart, Sheila A

    2014-01-01

    The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents. PMID:24396138

  5. Obesity epidemic: time to swallow the frog.

    PubMed

    Andersen, Ross E

    2003-11-01

    Mark Twain once said, "If you have to swallow a frog, don't stare at it too long." I believe that members of the healthcare community have been staring at the obesity epidemic for too long. PMID:20086443

  6. Meeting the "Standards" with Vanishing Frogs.

    ERIC Educational Resources Information Center

    Davidson, Cindy B.; Matthews, Catherine E.; Patrick, Patricia

    2001-01-01

    Explains methods for introducing high school students to the issue of the declining amphibian population. Plays the game Frogs' Futures following a seminar as an instructional strategy. Describes the game, procedures, and rules. (YDS)

  7. From Virtual Frog to Frog Island: Design Studies in a Development Project.

    ERIC Educational Resources Information Center

    Dev, Parvati; Walker, Decker F.

    1999-01-01

    Explores the efforts of a curriculum development team who set out to create a virtual frog for use in biology education, but instead, after several design studies, developed a virtual world called Frog Island. Argues for incorporating educational design studies into other educational development projects. (CMK)

  8. Nutrient allocation among plant organs across 13 tree species in three Bornean rain forests with contrasting nutrient availabilities.

    PubMed

    Aoyagi, Ryota; Kitayama, Kanehiro

    2016-07-01

    Allocation of nitrogen (N) and phosphorus (P) among plant organs is an important factor regulating growth rate, which is a key ecological process associated with plant life-history strategies. However, few studies have explored how N and P investment in photosynthetic (leaves) and non-photosynthetic (stems and roots) organs changes in relation to depletion of each element. We investigated nutrient concentrations of plant organs in relation to whole-plant nutrient concentration (total nutrient weight per total biomass) as an index of nutrient status of each individual using the saplings of the 13 species in three tropical rain forests with contrasting N and P availabilities (tropical evergreen forests and tropical heath forests). We found a steeper decrease in foliar N concentration than foliar P concentration with decreasing whole-plant nutrient concentration. Moreover, the steeper decrease in foliar N concentration was associated with relatively stable N concentration in stems, and vice versa for P. We suggest that the depletion of N is associated with a rapid dilution of foliar N because the cell walls in non-photosynthetic organs function as an N sink. On the other hand, these species can maintain foliar P concentration by decreasing stem P concentrations despites the depletion of P. Our results emphasize the significance of non-photosynthetic organs as an N sink for understanding the variation of foliar nutrient concentrations for the tree species in the three Bornean rain forests with different N and P availabilities. PMID:27056098

  9. Predicting the Invasion Potential of a Puerto Rican Frog in Hawaii using MODIS Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Bisrat, S. A.; White, M. A.

    2008-12-01

    The Puerto Rican coqui frog (Eleutherodactylus coqui, hereafter coqui), which was introduced into Hawaii accidentally via commercial nurseries, is an aggressive invasive species in Hawaii. The coqui threatens Hawaii's unique ecological communities because it predates upon endemic invertebrates, which comprise the large majority of Hawaii's endemic fauna. Coqui frogs also affect real estate valuations because of their loud mating calls. Despite this widespread problem, the potential coqui range in Hawaii is currently unknown, making control and management efforts difficult. We fitted linear discriminant analysis (LDA), logistic regression (LR) via generalized linear models (GLMs), generalized additive models (GAMs), classification trees (CTs), random forests (RF), and support vector machine (SVM) to model the species distribution and map their invasion potential. We used five MODIS satellite imagery-derived biophysical variables as explanatory variables: leaf area index (LAI), fraction of photosynthetically active radiation absorbed by vegetation (FPAR), enhanced vegetation index (EVI), normalized difference vegetation index (NDVI), and land surface temperature (LST) from three MODIS products: MOD11 (LST), MOD13 (LAI and FPAR), and MOD15 (Vegetation Index) (collection 4). We used 2000-2005 MODIS data from Aqua and Terra satellites to generate monthly climatologies for each biophysical variable. We collected presence/absence data from Puerto Rico and Hawaii using a 1 km grid overlaid over the entire islands of Puerto Rico and the Island of Hawaii by sampling every other pixel of the grid intersecting with the road network. We then used the dataset from Puerto Rico to train the six models while the Hawaii dataset was used as a test set. All six models predicted the invasion potential of coqui frogs in Hawaii with a moderate success with mean Kappa value of 0.31, mean area under the curve of receiver operating characteristics (AUC) of 0.75 and mean classification

  10. Endemicity of chytridiomycosis features pathogen overdispersion.

    PubMed

    Grogan, Laura F; Phillott, Andrea D; Scheele, Benjamin C; Berger, Lee; Cashins, Scott D; Bell, Sara C; Puschendorf, Robert; Skerratt, Lee F

    2016-05-01

    Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an overdispersed pathogen load distribution between hosts (where few hosts harbour heavy parasite burdens and light infections are common) can have an important stabilizing effect on host-pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. Overdispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild-caught Litoria rheocola (common mist frogs) to investigate the effects of an overdispersed pathogen load distribution on the host population in the wild. We quantified host survival, infection incidence and recovery probabilities relative to infectious burden, and compared the results of models where pathogen overdispersion either was or was not considered an important feature of host-pathogen dynamics. We found the distribution of Bd load between hosts to be highly overdispersed. We found that host survival was related to infection burden and that accounting for pathogen overdispersion allowed us to better understand infection dynamics and their implications for disease control. In addition, we found that the pattern of host infections and recoveries varied markedly with season whereby (i) infections established more in winter, consistent with temperature-dependent effects on fungal growth, and (ii) recoveries (loss of infection) occurred frequently in the field throughout the year but were less likely in winter. Our results suggest that pathogen overdispersion is an important feature of endemic

  11. TERATOGENESIS, TOXICITY, AND BIOCONCENTRATION IN FROGS EXPOSED TO DIELDRIN

    EPA Science Inventory

    Teratogenesis, acute and chronic toxicity, and bioconcentration were investigated in various like stages of African clawed frogs (Xenopus laevis), bullfrogs (Rana catesbeiana) and leopard frogs (Rana pipiens) exposed to aqueous dieldrin in static-renewal and continuous-flow tests...

  12. New Material of Beelzebufo, a Hyperossified Frog (Amphibia: Anura) from the Late Cretaceous of Madagascar

    PubMed Central

    Evans, Susan E.; Groenke, Joseph R.; Jones, Marc E. H.; Turner, Alan H.; Krause, David W.

    2014-01-01

    The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates. PMID:24489877

  13. 49 CFR 213.141 - Self-guarded frogs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If...

  14. 49 CFR 213.141 - Self-guarded frogs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If...

  15. 49 CFR 213.141 - Self-guarded frogs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If...

  16. 49 CFR 213.141 - Self-guarded frogs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If...

  17. 49 CFR 213.141 - Self-guarded frogs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If...

  18. 49 CFR 213.139 - Spring rail frogs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The... wing rail shall be solidly tamped and fully and tightly bolted. (c) Each frog with a bolt hole...

  19. Hands-on Science. How Do Polliwogs Become Frogs?

    ERIC Educational Resources Information Center

    Kepler, Lynne

    1993-01-01

    Describes a miniscience unit on frogs for elementary grades that teaches students about how frogs develop from tadpoles and how frogs need water during their entire life cycle. Students learn such skills as observation, collecting, and recording data. Provides addresses for ordering resources for teachers and students. (SM)

  20. Frog Swarms: Earthquake Precursors or False Alarms?

    PubMed Central

    Grant, Rachel A.; Conlan, Hilary

    2013-01-01

    Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by

  1. Newly discovered populations of the Ethiopian endemic and endangered Afrixalus clarkei Largen, implications for conservation.

    PubMed

    Mertens, Jan; Jocqué, Merlijn; Geeraert, Lore; Beenhouwer, Matthias De

    2016-01-01

    Knowledge of the Ethiopian amphibian fauna is limited and Southwest Ethiopia remains understudied. This part of Ethiopia, where most of the country's remaining natural forest is situated, is known to harbour the only populations of Afrixalus clarkei (Largen), an endemic banana frog, worldwide. This species is under great threat of extinction and is therefore classified as endangered on the IUCN red list. We surveyed different potential habitats for this species outside its known range and found several new populations extending its known habitat preference, and the geographical and altitudinal range of the species. We here show that Afrixalus clarkei is more common than previously thought. PMID:27081339

  2. Newly discovered populations of the Ethiopian endemic and endangered Afrixalus clarkei Largen, implications for conservation

    PubMed Central

    Mertens, Jan; Jocqué, Merlijn; Geeraert, Lore; Beenhouwer, Matthias De

    2016-01-01

    Abstract Knowledge of the Ethiopian amphibian fauna is limited and Southwest Ethiopia remains understudied. This part of Ethiopia, where most of the country’s remaining natural forest is situated, is known to harbour the only populations of Afrixalus clarkei (Largen), an endemic banana frog, worldwide. This species is under great threat of extinction and is therefore classified as endangered on the IUCN red list. We surveyed different potential habitats for this species outside its known range and found several new populations extending its known habitat preference, and the geographical and altitudinal range of the species. We here show that Afrixalus clarkei is more common than previously thought. PMID:27081339

  3. THE PROPELLER AND THE FROG

    SciTech Connect

    Pan, Margaret; Chiang, Eugene

    2010-10-20

    'Propellers' in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the 'frog' resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bleriot in Saturn's A ring, our theory predicts a libration period of {approx}4 years, similar to the {approx}3.7 year period over which Bleriot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

  4. `Unstirred layers' in frog skin

    PubMed Central

    Dainty, J.; House, C. R.

    1966-01-01

    1. Estimates of the magnitudes of the unstirred regions associated with isolated frog skin in sulphate Ringer's solution have been made under different stirring conditions. 2. The method of investigation was an analysis of the time course of the p.d. transients which occurred when external sodium concentration and internal potassium concentration changes were made in the bathing solution. 3. Making an arbitrary but reasonable assumption about the diffusional coefficient of Na2SO4 in the outer unstirred region, the magnitudes of the outer unstirred layers were found to lie within the ranges 40-60 μ, 30-50 μ and 30-40 μ under stirring conditions of 120, 300 and 500 rev/min, respectively. 4. Making an arbitrary but reasonable assumption about the diffusion coefficient of K2SO4 in the inner unstirred region, the magnitudes of the inner unstirred layers were found to lie within the ranges 150-230 μ, 120-200 μ and 100-170 μ under stirring conditions of 120, 300 and 500 rev/min, respectively. PMID:5937417

  5. The Propeller and the Frog

    NASA Astrophysics Data System (ADS)

    Pan, Margaret; Chiang, Eugene

    2010-10-01

    "Propellers" in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the "frog" resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Blériot in Saturn's A ring, our theory predicts a libration period of ~4 years, similar to the ~3.7 year period over which Blériot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

  6. The nature of serpentine endemism.

    PubMed

    Anacker, Brian L

    2014-02-01

    Serpentine soils are a model system for the study of plant adaptation, speciation, and species interactions. Serpentine soil is an edaphically stressful, low productivity soil type that hosts stunted vegetation and a spectacular level of plant endemism. One of the first papers on serpentine plant endemism was by Arthur Kruckeberg, titled "Intraspecific variability in the response of certain native plant species to serpentine soil." Published in the American Journal of Botany in 1951, it has been cited over 100 times. Here, I review the context and content of the paper, as well as its impact. On the basis of the results of reciprocal transplant experiments in the greenhouse, Kruckeberg made three important conclusions on the nature of serpentine plant endemism: (1) Plants are locally adapted to serpentine soils, forming distinct soil ecotypes; (2) soil ecotypes are the first stage in the evolutionary progression toward serpentine endemism; and (3) serpentine endemics are restricted from more fertile nonserpentine soils by competition. Kruckeberg's paper inspired a substantial amount of research, especially in the three areas reviewed here: local adaptation and plant traits, speciation, and the interaction of climate and soil in plant endemism. In documenting soil ecotypes, Kruckeberg identified serpentine soils as a potent selective factor in plant evolution and helped establish serpentine soils as a model system in evolution and ecology. PMID:24509800

  7. Frog skin epithelium: electrolyte transport and chytridiomycosis.

    PubMed

    Campbell, Craig R; Voyles, Jamie; Cook, David I; Dinudom, Anuwat

    2012-03-01

    One unique physiological characteristic of frogs is that their main route for intake of water is across the skin. In these animals, the skin acts in concert with the kidney and urinary bladder to maintain electrolyte homeostasis. Water absorption across the skin is driven by the osmotic gradient that develops as a consequence of solute transport. Our recent study demonstrated that chytridiomycosis, an infection of amphibian skin by the fungal pathogen, Batrachochytrium dendrobatidis, inhibits epithelial Na(+) channels, attenuating Na(+) absorption through the skin. In frogs that become severely affected by this fungus, systemic depletion of Na(+), K(+) and Cl(-) is thought to cause deterioration of cardiac electrical function, leading to cardiac arrest. Here we review the ion transport mechanisms of frog skin, and discuss the effect of chytridiomycosis on these mechanisms. PMID:22182598

  8. Frog skin epithelium: electrolyte transport and chytridiomycosis

    PubMed Central

    Campbell, Craig R.; Voyles, Jamie; Cook, David I.; Dinudom, Anuwat

    2012-01-01

    One unique physiological characteristic of frogs is that their main route for intake of water is across the skin. In these animals, the skin acts in concert with the kidney and urinary bladder to maintain electrolyte homeostasis. Water absorption across the skin is driven by the osmotic gradient that develops as a consequence of solute transport. Our recent study demonstrated that chytridiomycosis, an infection of amphibian skin by the fungal pathogen, Batrachochytrium dendrobatidis, inhibits epithelial Na+ channels, attenuating Na+ absorption through the skin. In frogs that become severely affected by this fungus, systemic depletion of Na+, K+ and Cl− is thought to cause deterioration of cardiac electrical function, leading to cardiac arrest. Here we review the ion transport mechanisms of frog skin, and discuss the effect of chytridiomycosis on these mechanisms. PMID:22182598

  9. Calculation of Individual Tree Water Use in a Bornean Tropical Rain Forest Using Individual-Based Dynamic Vegetation Model SEIB-DGVM

    NASA Astrophysics Data System (ADS)

    Nakai, T.; Kumagai, T.; Saito, T.; Matsumoto, K.; Kume, T.; Nakagawa, M.; Sato, H.

    2015-12-01

    Bornean tropical rain forests are among the moistest biomes of the world with abundant rainfall throughout the year, and considered to be vulnerable to a change in the rainfall regime; e.g., high tree mortality was reported in such forests induced by a severe drought associated with the ENSO event in 1997-1998. In order to assess the effect (risk) of future climate change on eco-hydrology in such tropical rain forests, it is important to understand the water use of trees individually, because the vulnerability or mortality of trees against climate change can depend on the size of trees. Therefore, we refined the Spatially Explicit Individual-Based Dynamic Global Vegetation Model (SEIB-DGVM) so that the transpiration and its control by stomata are calculated for each individual tree. By using this model, we simulated the transpiration of each tree and its DBH-size dependency, and successfully reproduced the measured data of sap flow of trees and eddy covariance flux data obtained in a Bornean lowland tropical rain forest in Lambir Hills National Park, Sarawak, Malaysia.

  10. A unique resource mutualism between the giant Bornean pitcher plant, Nepenthes rajah, and members of a small mammal community.

    PubMed

    Greenwood, Melinda; Clarke, Charles; Lee, Ch'ien C; Gunsalam, Ansou; Clarke, Rohan H

    2011-01-01

    The carnivorous pitcher plant genus Nepenthes grows in nutrient-deficient substrates and produce jug-shaped leaf organs (pitchers) that trap arthropods as a source of N and P. A number of Bornean Nepenthes demonstrate novel nutrient acquisition strategies. Notably, three giant montane species are engaged in a mutualistic association with the mountain treeshrew, Tupaia montana, in which the treeshrew defecates into the pitchers while visiting them to feed on nectar secretions on the pitchers' lids.Although the basis of this resource mutualism has been elucidated, many aspects are yet to be investigated. We sought to provide insights into the value of the mutualism to each participant. During initial observations we discovered that the summit rat, R. baluensis, also feeds on sugary exudates of N. rajah pitchers and defecates into them, and that this behavior appears to be habitual. The scope of the study was therefore expanded to assess to what degree N. rajah interacts with the small mammal community.We found that both T. montana and R. baluensis are engaged in a mutualistic interaction with N. rajah. T .montana visit pitchers more frequently than R. baluensis, but daily scat deposition rates within pitchers do not differ, suggesting that the mutualistic relationships are of a similar strength. This study is the first to demonstrate that a mutualism exists between a carnivorous plant species and multiple members of a small mammal community. Further, the newly discovered mutualism between R. baluensis and N. rajah represents only the second ever example of a multidirectional resource-based mutualism between a mammal and a carnivorous plant. PMID:21695073

  11. A Unique Resource Mutualism between the Giant Bornean Pitcher Plant, Nepenthes rajah, and Members of a Small Mammal Community

    PubMed Central

    Greenwood, Melinda; Clarke, Charles; Lee, Ch'ien C.; Gunsalam, Ansou; Clarke, Rohan H.

    2011-01-01

    The carnivorous pitcher plant genus Nepenthes grows in nutrient-deficient substrates and produce jug-shaped leaf organs (pitchers) that trap arthropods as a source of N and P. A number of Bornean Nepenthes demonstrate novel nutrient acquisition strategies. Notably, three giant montane species are engaged in a mutualistic association with the mountain treeshrew, Tupaia montana, in which the treeshrew defecates into the pitchers while visiting them to feed on nectar secretions on the pitchers' lids. Although the basis of this resource mutualism has been elucidated, many aspects are yet to be investigated. We sought to provide insights into the value of the mutualism to each participant. During initial observations we discovered that the summit rat, R. baluensis, also feeds on sugary exudates of N. rajah pitchers and defecates into them, and that this behavior appears to be habitual. The scope of the study was therefore expanded to assess to what degree N. rajah interacts with the small mammal community. We found that both T. montana and R. baluensis are engaged in a mutualistic interaction with N. rajah. T .montana visit pitchers more frequently than R. baluensis, but daily scat deposition rates within pitchers do not differ, suggesting that the mutualistic relationships are of a similar strength. This study is the first to demonstrate that a mutualism exists between a carnivorous plant species and multiple members of a small mammal community. Further, the newly discovered mutualism between R. baluensis and N. rajah represents only the second ever example of a multidirectional resource-based mutualism between a mammal and a carnivorous plant. PMID:21695073

  12. Human-assisted invasions of pacific islands by litoria frogs: a case study of the bleating tree frog on Lord Howe Island.

    PubMed

    Plenderleith, T Lynette; Smith, Katie L; Donnellan, Stephen C; Reina, Richard D; Chapple, David G

    2015-01-01

    There are substantial differences among taxonomic groups in their capacity to reach remote oceanic islands via long-distance overwater dispersal from mainland regions. Due to their permeable skin and intolerance of saltwater, amphibians generally require human-assisted dispersal to reach oceanic islands. Several Litoria frog species have been introduced to remote islands throughout the Pacific Ocean region. Lord Howe Island (LHI) is an oceanic island that lies approximately 600 km east of the Australian mainland and has a diverse, endemic biota. The bleating tree frog (Litoria dentata) is native to mainland eastern Australia, but was accidentally introduced to LHI in the 1990s, yet its ecology and potential impact on LHI has remained unstudied. We used a mitochondrial phylogeographical approach to determine that L. dentata was introduced from the Ballina region in northeastern New South Wales. The founding population was likely accidentally introduced with cargo shipped from the mainland. We also completed the first detailed investigation of the distribution, ecology and habitat use of L. dentata on LHI. The species is widespread on LHI and is prevalent in human habitat, cattle pasture and undisturbed forest. We discuss the potential impact of introduced Litoria species on Pacific islands and outline what biosecurity protocols could be implemented to prevent the introduction of further amphibian species to the ecologically sensitive oceanic area. PMID:25962141

  13. Human-Assisted Invasions of Pacific Islands by Litoria Frogs: A Case Study of the Bleating Tree Frog on Lord Howe Island

    PubMed Central

    Plenderleith, T. Lynette; Smith, Katie L.; Donnellan, Stephen C.; Reina, Richard D.; Chapple, David G.

    2015-01-01

    There are substantial differences among taxonomic groups in their capacity to reach remote oceanic islands via long-distance overwater dispersal from mainland regions. Due to their permeable skin and intolerance of saltwater, amphibians generally require human-assisted dispersal to reach oceanic islands. Several Litoria frog species have been introduced to remote islands throughout the Pacific Ocean region. Lord Howe Island (LHI) is an oceanic island that lies approximately 600 km east of the Australian mainland and has a diverse, endemic biota. The bleating tree frog (Litoria dentata) is native to mainland eastern Australia, but was accidentally introduced to LHI in the 1990s, yet its ecology and potential impact on LHI has remained unstudied. We used a mitochondrial phylogeographical approach to determine that L. dentata was introduced from the Ballina region in northeastern New South Wales. The founding population was likely accidentally introduced with cargo shipped from the mainland. We also completed the first detailed investigation of the distribution, ecology and habitat use of L. dentata on LHI. The species is widespread on LHI and is prevalent in human habitat, cattle pasture and undisturbed forest. We discuss the potential impact of introduced Litoria species on Pacific islands and outline what biosecurity protocols could be implemented to prevent the introduction of further amphibian species to the ecologically sensitive oceanic area. PMID:25962141

  14. Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

    USGS Publications Warehouse

    Rittman, S.E.; Muths, E.; Green, D.E.

    2003-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

  15. Frog egg growth, experiment S003

    NASA Technical Reports Server (NTRS)

    Young, R. S.; Tremor, J. W.

    1971-01-01

    The objective of experiment was to determine the effect of weightlessness on the ability of a fertilized frog egg to divide normally and to differentiate and form a normal embryo. This experiment was first attempted on the Gemini 8 mission and was completed only partially because of the early termination of that mission.

  16. Venomous Frogs Use Heads as Weapons.

    PubMed

    Jared, Carlos; Mailho-Fontana, Pedro Luiz; Antoniazzi, Marta Maria; Mendes, Vanessa Aparecida; Barbaro, Katia Cristina; Rodrigues, Miguel Trefaut; Brodie, Edmund D

    2015-08-17

    Venomous animals have toxins associated with delivery mechanisms that can introduce the toxins into another animal. Although most amphibian species produce or sequester noxious or toxic secretions in the granular glands of the skin to use as antipredator mechanisms, amphibians have been considered poisonous rather than venomous because delivery mechanisms are absent. The skin secretions of two Brazilian hylid frogs (Corythomantis greening and Aparasphenodon brunoi) are more toxic than the venoms of deadly venomous Brazilian pitvipers, genus Bothrops; C. greeningi secretion is 2-fold and A. brunoi secretion is 25-fold as lethal as Bothrops venom. Like the venoms of other animals, the skin secretions of these frogs show proteolytic and fibrinolytic activity and have hyaluronidase, which is nontoxic and nonproteolytic but promotes diffusion of toxins. These frogs have well-developed delivery mechanisms, utilizing bony spines on the skull that pierce the skin in areas with concentrations of skin glands. C. greeningi has greater development of head spines and enlarged skin glands producing a greater volume of secretion, while A. brunoi has more lethal venom. C. greeningi and A. brunoi have highly toxic skin secretions and an associated delivery mechanism; they are therefore venomous. Because even tiny amounts of these secretions introduced into a wound caused by the head spines could be dangerous, these frogs are capable of using their skin toxins as venoms against would-be predators. PMID:26255851

  17. Frog Swarms: Earthquake Precursors or False Alarms?

    PubMed

    Grant, Rachel A; Conlan, Hilary

    2013-01-01

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

  18. Skin bacterial diversity of Panamanian frogs is associated with host susceptibility and presence of Batrachochytrium dendrobatidis.

    PubMed

    Rebollar, Eria A; Hughey, Myra C; Medina, Daniel; Harris, Reid N; Ibáñez, Roberto; Belden, Lisa K

    2016-07-01

    Symbiotic bacteria on amphibian skin can inhibit growth of the fungus Batrachochytrium dendrobatidis (Bd) that has caused dramatic population declines and extinctions of amphibians in the Neotropics. It remains unclear how the amphibians' skin microbiota is influenced by environmental bacterial reservoirs, host-associated factors such as susceptibility to pathogens, and pathogen presence in tropical amphibians. We sampled skin bacteria from five co-occurring frog species that differ in Bd susceptibility at one Bd-naive site, and sampled one of the non-susceptible species from Bd-endemic and Bd-naive sites in Panama. We hypothesized that skin bacterial communities (1) would be distinct from the surrounding environment regardless of the host habitat, (2) would differ between Bd susceptible and non-susceptible species and (3) would differ on hosts in Bd-naive and Bd-endemic sites. We found that skin bacterial communities were enriched in bacterial taxa that had low relative abundances in the environment. Non-susceptible species had very similar skin bacterial communities that were enriched in particular taxa such as the genera Pseudomonas and Acinetobacter. Bacterial communities of Craugastor fitzingeri in Bd-endemic sites were less diverse than in the naive site, and differences in community structure across sites were explained by changes in relative abundance of specific bacterial taxa. Our results indicate that skin microbial structure was associated with host susceptibility to Bd and might be associated to the history of Bd presence at different sites. PMID:26744810

  19. Hyperspectral analysis of columbia spotted frog habitat

    USGS Publications Warehouse

    Shive, J.P.; Pilliod, D.S.; Peterson, C.R.

    2010-01-01

    Wildlife managers increasingly are using remotely sensed imagery to improve habitat delineations and sampling strategies. Advances in remote sensing technology, such as hyperspectral imagery, provide more information than previously was available with multispectral sensors. We evaluated accuracy of high-resolution hyperspectral image classifications to identify wetlands and wetland habitat features important for Columbia spotted frogs (Rana luteiventris) and compared the results to multispectral image classification and United States Geological Survey topographic maps. The study area spanned 3 lake basins in the Salmon River Mountains, Idaho, USA. Hyperspectral data were collected with an airborne sensor on 30 June 2002 and on 8 July 2006. A 12-year comprehensive ground survey of the study area for Columbia spotted frog reproduction served as validation for image classifications. Hyperspectral image classification accuracy of wetlands was high, with a producer's accuracy of 96 (44 wetlands) correctly classified with the 2002 data and 89 (41 wetlands) correctly classified with the 2006 data. We applied habitat-based rules to delineate breeding habitat from other wetlands, and successfully predicted 74 (14 wetlands) of known breeding wetlands for the Columbia spotted frog. Emergent sedge microhabitat classification showed promise for directly predicting Columbia spotted frog egg mass locations within a wetland by correctly identifying 72 (23 of 32) of known locations. Our study indicates hyperspectral imagery can be an effective tool for mapping spotted frog breeding habitat in the selected mountain basins. We conclude that this technique has potential for improving site selection for inventory and monitoring programs conducted across similar wetland habitat and can be a useful tool for delineating wildlife habitats. ?? 2010 The Wildlife Society.

  20. ENDEMIC DISEASES VS. ACUTE EPIDEMICS

    PubMed Central

    Ravenel, Mazÿck P.

    1920-01-01

    Epidemics are cared for through the incident terror of the people, and there is always money to fight them and investigate, but the far more important insidious endemics attract little interest or popular support. Attention to reduction in morbidity, rather than mortality, rates is the “stitch in time” plea of Dr. Ravenel. PMID:18010377

  1. Endemic treponematoses in the Sudan

    PubMed Central

    Grin, E. I.

    1961-01-01

    It has been recognized for many years that Africa contains a very large reservoir of endemic treponematoses, and all information on the foci of infection contributes to the goal of elimination of these diseases as public health problems. In 1959 the author undertook, at the request of the Sudanese Government, a number of pilot surveys in areas where the endemic treponematoses were thought to be prevalent. From the information acquired in these surveys and from official data it is clear that yaws and endemic syphilis are a major problem of public health in the Sudan. It is estimated that some 5 million people in six provinces are at risk, and that about 20% of the population in an area of 1 543 000 km2 suffer from one or the other of the two diseases in the active clinical stage. In some localities yaws was found to be prevalent, and in some endemic syphilis. In others, the two infections were seen to co-exist; and it is suggested that, since little is known of the extent to which one infection confers protection against the other, the situation in the Sudan provides a perhaps unique opportunity for scientific studies of the interrelationship of these two diseases and their possible relationship with venereal syphilis. Another interesting finding, worthy of further investigation, was that mucous lesions occurred only in areas where syphilis was present and not where yaws alone was prevalent. PMID:13708748

  2. The role of extensional viscosity in frog tongue projection

    NASA Astrophysics Data System (ADS)

    Noel, Alexis; Wagner, Caroline; McKinley, Gareth; Mendelson, Joe; Hu, David

    2014-11-01

    Frogs and other amphibians capture insects through high-speed tongue projection, some achieving tongue accelerations of over fifty times gravity. In this experimental study, we investigate how a frog's sticky saliva enables high-speed prey capture. At the Atlanta zoo, we used high-speed video to film the trajectory of frog tongues during prey capture. We have also designed and built a portable extensional rheometer; by following the capillary-driven thinning in the diameter of a thread of saliva we characterize the relaxation time and extensional viscosity and so infer the adhesive force between the frog tongue and prey.

  3. Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment.

    PubMed

    Vijayakumar, S P; Menezes, Riya C; Jayarajan, Aditi; Shanker, Kartik

    2016-08-17

    The historical processes underlying high diversity in tropical biodiversity hotspots like the Western Ghats of Peninsular India remain poorly understood. We sampled bush frogs on 13 massifs across the Western Ghats Escarpment and examined the relative influence of Quaternary glaciations, ecological gradients and geological processes on the spatial patterns of lineage and clade diversification. The results reveal a large in situ radiation (more than 60 lineages), exhibiting geographical structure and clade-level endemism, with two deeply divergent sister clades, North and South, highlighting the biogeographic significance of an ancient valley, the Palghat Gap. A majority of the bush frog sister lineages were isolated on adjacent massifs, and signatures of range stasis provide support for the dominance of geological processes in allopatric speciation. In situ diversification events within the montane zones (more than 1800 m) of the two highest massifs suggest a role for climate-mediated forest-grassland persistence. Independent transitions along elevational gradients among sub-clades during the Miocene point to diversification along the elevational gradient. The study highlights the evolutionary significance of massifs in the Western Ghats with the high elevations acting as centres of lineage diversification and the low- and mid-elevations of the southern regions, with deeply divergent lineages, serving as museums. PMID:27534957

  4. Ontogenetic Development of the Derived Olfactory System of the Mantellid Frog Mantidactylus betsileanus.

    PubMed

    Nowack, Christine; Vences, Miguel

    2016-07-01

    The nasal cavity of Mantidactylus betsileanus, a frog of the Madagascar-Comoroan endemic family Mantellidae, is characterized by a unique internal architecture. Unlike the state commonly observed in anurans, the two discernible olfactory subsystems of M. betsileanus (the main olfactory organ and the vomeronasal organ) are anatomically separated from each other, suggesting an enhanced functional differentiation. Here we evaluate the ontogenetic formation of this extraordinary anatomical state based on a histological study of a developmental series of M. betsileanus. The olfactory system of premetamorphic tadpoles, and most of its changes during metamorphosis, resembles that of other anurans. At the end of metamorphosis however, a growing obstruction of the passage between main olfactory organ and vomeronasal organ takes place, leading to the deviant morphological state previously described for adults. The late appearance of this atypical anatomical feature in the course of ontogeny agrees with the phylogenetic hypothesis of the observed obstruction representing a derived state for these frogs. From a functional point of view, the apparent autonomy of the vomeronasal organ is possibly linked to the presence of clade-specific femoral glands that are known to produce pheromones and that likewise are fully expressed in adults only. Anat Rec, 299:943-950, 2016. © 2016 Wiley Periodicals, Inc. PMID:27084295

  5. Unearthing the Fossorial Tadpoles of the Indian Dancing Frog Family Micrixalidae

    PubMed Central

    Senevirathne, Gayani; Garg, Sonali; Kerney, Ryan; Meegaskumbura, Madhava; Biju, S. D.

    2016-01-01

    Tadpoles of the monotypic Indian dancing frog family Micrixalidae have remained obscure for over 125 years. Here we report the discovery of the elusive tadpoles of Micrixalus herrei from the sand beds of a forested stream in southern Western Ghats, and confirm their identity through DNA barcoding. These actively burrowing tadpoles lead an entirely fossorial life from eggs to late metamorphic stages. We describe their internal and external morphological characters while highlighting the following features: eel-like appearance, extensively muscularized body and tail, reduced tail fins, skin-covered eyes, delayed development of eye pigmentation in early pre-metamorphic stages (Gosner stages 25–29), prominent tubular sinistral spiracle, large transverse processes on vertebrae II and III, ankylosed ribs on transverse processes of vertebra II, notochord terminating before the atlantal cotyle-occipital condyle junction, absence of keratodonts, serrated well-formed jaw sheaths, and extensive calcified endolymphatic sacs reaching sacrum posteriorly. The tadpole gut contains mostly fine sediments and sand. We discuss the eel-like morphology and feeding habits of M. herrei in the context of convergence with other well-known fossorial tadpoles. This discovery builds the knowledge base for further comparative analyses and conservation of Micrixalus, an ancient and endemic lineage of Indian frogs. PMID:27027870

  6. Unearthing the Fossorial Tadpoles of the Indian Dancing Frog Family Micrixalidae.

    PubMed

    Senevirathne, Gayani; Garg, Sonali; Kerney, Ryan; Meegaskumbura, Madhava; Biju, S D

    2016-01-01

    Tadpoles of the monotypic Indian dancing frog family Micrixalidae have remained obscure for over 125 years. Here we report the discovery of the elusive tadpoles of Micrixalus herrei from the sand beds of a forested stream in southern Western Ghats, and confirm their identity through DNA barcoding. These actively burrowing tadpoles lead an entirely fossorial life from eggs to late metamorphic stages. We describe their internal and external morphological characters while highlighting the following features: eel-like appearance, extensively muscularized body and tail, reduced tail fins, skin-covered eyes, delayed development of eye pigmentation in early pre-metamorphic stages (Gosner stages 25-29), prominent tubular sinistral spiracle, large transverse processes on vertebrae II and III, ankylosed ribs on transverse processes of vertebra II, notochord terminating before the atlantal cotyle-occipital condyle junction, absence of keratodonts, serrated well-formed jaw sheaths, and extensive calcified endolymphatic sacs reaching sacrum posteriorly. The tadpole gut contains mostly fine sediments and sand. We discuss the eel-like morphology and feeding habits of M. herrei in the context of convergence with other well-known fossorial tadpoles. This discovery builds the knowledge base for further comparative analyses and conservation of Micrixalus, an ancient and endemic lineage of Indian frogs. PMID:27027870

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

    PubMed Central

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

    2010-01-01

    Microfungi were recovered from all parts of a municipal water distribution system in sub-tropical Australia even though virtually no colony-forming units were recovered from the treated water as it left the treatment plant. A study was then undertaken to determine the potential sources of the microfungal population in the distribution system. Observation of frogs (Litoria caerulea) using the internal infrastructure of a reservoir as diurnal sleeping places, together with observation of visible microfungal growth on their faecal pellets, led to an investigation of the possible involvement of this animal. Old faecal pellets were collected and sporulating fungal colonies growing on their surfaces were identified. Fresh faecal pellets were collected and analysed for microfungal content, and skin swabs were analysed for yeasts. It was found that the faeces and skin of L. caerulea carried large numbers of yeasts as well as spores of various filamentous fungal genera. While there are many possible sources of microfungal contamination of municipal drinking water supplies, this study has revealed that the Australian green tree frog L. caerulea is one of the important sources of filamentous microfungi and yeasts in water storage reservoirs in sub-tropical Australia where the animal is endemic. PMID:20948957

  8. Yolk pigments of the Mexican leaf frog.

    PubMed

    Marinetti, G V; Bagnara, J T

    1983-02-25

    Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha. The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These pigments may provide protective coloration to the eggs. PMID:6681678

  9. Arthropod predation in a dendrobatid poison frog: does frog life stage matter?

    PubMed

    Murray, Erin M; Bolton, Sarah K; Berg, Torsten; Saporito, Ralph A

    2016-06-01

    Frogs in the family Dendrobatidae are well known for their conspicuous colors and variable alkaloid-based chemical defenses. The aposematic coloration in dendrobatid frogs appears to deter predators with color vision, but relatively little is known about how these frogs are protected and their defenses are perceived by non-color vision dominated predators. The neotropical bullet ant Paraponera clavata and the red-legged banana spider Cupiennius coccineus are predators that avoid adults of the dendrobatid Oophaga pumilio, but readily consume non-toxic frogs. Juvenile O. pumilio possess the same warning coloration as adult O. pumilio, but may be more palatable given that they have lower quantities of defensive chemicals. This may provide juvenile O. pumilio protection from color-sighted predators, while leaving them susceptible to predators that use chemoreception. To test this hypothesis, we presented juveniles and adults of both O. pumilio and the non-chemically defended frog Craugastor bransfordii to bullet ants and banana spiders. Both bullet ants and banana spiders preyed upon C. bransfordii significantly more than on O. pumilio. Adult and juvenile C. bransfordii experienced similar predation rates by both predators. The life stage of O. pumilio significantly predicted predation by bullet ants, with juveniles being consumed significantly more often than adults. However, the life stage of O. pumilio did not predict predation by banana spiders, as no adults or juveniles were consumed. Our study provides evidence that bullet ants can detect differences in chemical defenses between juvenile and adult O. pumilio, resulting in differential predation on the more palatable juvenile frogs. The avoidance of both adults and juveniles by C. coccineus suggests the alkaloids in O. pumilio act as an effective chemical deterrent to banana spiders, regardless of quantity. Overall, our results suggest that differences in alkaloid defenses among life stages in O. pumilio

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

    ERIC Educational Resources Information Center

    Stephens, Philip J.

    2015-01-01

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

  11. 49 CFR 213.139 - Spring rail frogs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  12. 49 CFR 213.139 - Spring rail frogs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of...

  13. 49 CFR 213.139 - Spring rail frogs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of...

  14. 49 CFR 213.139 - Spring rail frogs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of...

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

    ERIC Educational Resources Information Center

    Goldsmith, Pat Rubio

    2011-01-01

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

  16. The need for water quality criteria for frogs.

    PubMed Central

    Boyer, R; Grue, C E

    1995-01-01

    Amphibians are considered reliable indicators of environmental quality. In the western United States, a general decline of frog populations parallels an apparent worldwide decline. The factors thought to be contributing to declines in frog populations include habitat loss, introduction of exotic species, overexploitation, disease, climate change, and decreasing water quality. With respect to water quality, agroecosystems use 80-90% of the water resources in the western United States, frequently resulting in highly eutrophic conditions. Recent investigations suggest that these eutrophic conditions (elevated pH, water temperature, and un-ionized ammonia) may be associated with frog embryo mortality or malformations. However, water quality criteria for frogs and other amphibians do not currently exist. Here, we briefly review data that support the need to develop water quality parameters for frogs in agroecosystems and other habitats. Images Figure 1. Figure 2. Figure 3. Figure 4. A Figure 4. B Figure 5. PMID:7607135

  17. Tongue adhesion in the horned frog Ceratophrys sp.

    NASA Astrophysics Data System (ADS)

    Kleinteich, Thomas; Gorb, Stanislav N.

    2014-06-01

    Frogs are well-known to capture elusive prey with their protrusible and adhesive tongues. However, the adhesive performance of frog tongues and the mechanism of the contact formation with the prey item remain unknown. Here we measured for the first time adhesive forces and tongue contact areas in living individuals of a horned frog (Ceratophrys sp.) against glass. We found that Ceratophrys sp. generates adhesive forces well beyond its own body weight. Surprisingly, we found that the tongues adhered stronger in feeding trials in which the coverage of the tongue contact area with mucus was relatively low. Thus, besides the presence of mucus, other features of the frog tongue (surface profile, material properties) are important to generate sufficient adhesive forces. Overall, the experimental data shows that frog tongues can be best compared to pressure sensitive adhesives (PSAs) that are of common technical use as adhesive tapes or labels.

  18. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  19. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  20. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  1. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  2. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  3. A giant frog with South American affinities from the Late Cretaceous of Madagascar

    PubMed Central

    Evans, Susan E.; Jones, Marc E. H.; Krause, David W.

    2008-01-01

    Madagascar has a diverse but mainly endemic frog fauna, the biogeographic history of which has generated intense debate, fueled by recent molecular phylogenetic analyses and the near absence of a fossil record. Here, we describe a recently discovered Late Cretaceous anuran that differs strikingly in size and morphology from extant Malagasy taxa and is unrelated either to them or to the predicted occupants of the Madagascar–Seychelles–India landmass when it separated from Africa 160 million years ago (Mya). Instead, the previously undescribed anuran is attributed to the Ceratophryinae, a clade previously considered endemic to South America. The discovery offers a rare glimpse of the anuran assemblage that occupied Madagascar before the Tertiary radiation of mantellids and microhylids that now dominate the anuran fauna. In addition, the presence of a ceratophryine provides support for a controversial paleobiogeographical model that posits physical and biotic links among Madagascar, the Indian subcontinent, and South America that persisted well into the Late Cretaceous. It also suggests that the initial radiation of hyloid anurans began earlier than proposed by some recent estimates. PMID:18287076

  4. Peatlands and green frogs: A relationship regulated by acidity?

    USGS Publications Warehouse

    Mazerolle, M.J.

    2005-01-01

    The effects of site acidification on amphibian populations have been thoroughly addressed in the last decades. However, amphibians in naturally acidic environments, such as peatlands facing pressure from the peat mining industry, have received little attention. Through two field studies and an experiment, I assessed the use of bog habitats by the green frog (Rana clamitans melanota), a species sensitive to various forestry and peat mining disturbances. First, I compared the occurrence and breeding patterns of frogs in bog and upland ponds. I then evaluated frog movements between forest and bog habitats to determine whether they corresponded to breeding or postbreeding movements. Finally, I investigated, through a field experiment, the value of bogs as rehydrating areas for amphibians by offering living Sphagnum moss and two media associated with uplands (i.e., water with pH ca 6.5 and water-saturated soil) to acutely dehydrated frogs. Green frog reproduction at bog ponds was a rare event, and no net movements occurred between forest and bog habitats. However, acutely dehydrated frogs did not avoid Sphagnum. Results show that although green frogs rarely breed in bogs and do not move en masse between forest and bog habitats, they do not avoid bog substrates for rehydrating, despite their acidity. Thus, bogs offer viable summering habitat to amphibians, which highlights the value of these threatened environments in terrestrial amphibian ecology.

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

    USGS Publications Warehouse

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

    2005-01-01

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

  6. Amphibian pathogens in Southeast Asian frog trade.

    PubMed

    Gilbert, Martin; Bickford, David; Clark, Leanne; Johnson, Arlyne; Joyner, Priscilla H; Ogg Keatts, Lucy; Khammavong, Kongsy; Nguyễn Văn, Long; Newton, Alisa; Seow, Tiffany P W; Roberton, Scott; Silithammavong, Soubanh; Singhalath, Sinpakhone; Yang, Angela; Seimon, Tracie A

    2012-12-01

    Amphibian trade is known to facilitate the geographic spread of pathogens. Here we assess the health of amphibians traded in Southeast Asia for food or as pets, focusing on Batrachochytrium dendrobatidis (Bd), ranavirus and general clinical condition. Samples were collected from 2,389 individual animals at 51 sites in Lao PDR, Cambodia, Vietnam and Singapore for Bd screening, and 74 animals in Cambodia and Vietnam for ranavirus screening. Bd was found in one frog (n = 347) in Cambodia and 13 in Singapore (n = 419). No Bd was found in Lao PDR (n = 1,126) or Vietnam (n = 497), and no ranavirus was found in Cambodia (n = 70) or Vietnam (n = 4). Mild to severe dermatological lesions were observed in all East Asian bullfrogs Hoplobatrachus rugolosus (n = 497) sampled in farms in Vietnam. Histologic lesions consistent with sepsis were found within the lesions of three frogs and bacterial sepsis in two (n = 4); one had Gram-negative bacilli and one had acid-fast organisms consistent with mycobacterium sp. These results confirm that Bd is currently rare in amphibian trade in Southeast Asia. The presence of Mycobacterium-associated disease in farmed H. rugolosus is a cause for concern, as it may have public health implications and indicates the need for improved biosecurity in amphibian farming and trade. PMID:23404036

  7. The extracellular compartments of frog skeletal muscle.

    PubMed Central

    Neville, M C; Mathias, R T

    1979-01-01

    1. Detailed studies of solute efflux from frog sartorius muscle and single muscle fibres were carried out in order to characterize a 'special region' (Harris, 1963) in the extracellular space of muscle and determine whether this 'special region' is the sarcoplasmic reticulum. 2. The efflux of radioactive Na, Cl, glusose, 3-O-methylglucose, xylose, glycine, leucine, cycloleucine, Rb, K, inulin (mol. wt. 5000) and dextran (mol. wt. 17,000) from previously loaded muscles was studied. In all cases except dextran the curve had three components, a rapid (A) component which could be equated with efflux from the extracellular space proper, a slow (C) component representing cellular solute and an intermediate (B) component. The distribution space for the B component was 8% of muscle volume in summer frogs and 12% in winter frogs and appeared to be equal for all compounds studied. We tested the hypothesis that the B component originated from the sarcoplasmic reticulum. 3. The C component was missing from the dextran curves. Both dextran and inulin entered the compartment of origin of the B component (compartment B) to the same extent as small molecules. 4. For all compounds studies, the efflux rate constant for the A component could be predicted from the diffusion coefficient. For the B component the efflux rate constant was 6--10 times slower than that for the A component but was still proportional to the diffusion coefficient for the solute in question. 5. When Na and sucrose efflux from single fibres was followed, a B component was usually observed. The average distribution space for this component was small, averaging 1.5% of fibre volume. There was no difference between the average efflux rate constants for Na and sucrose. 6. In an appendix, the constraints placed on the properties of a hypothetical channel between the sarcoplasmic reticulum and the T-system by the linear electrical parameters of frog skeletal muscle are derived. It is shown that the conductance of such

  8. Biosensor, ELISA, and frog embryo teratogenesis assay: Xenopus (FETAX) analysis of water associated with frog malformations in Minnesota

    NASA Astrophysics Data System (ADS)

    Garber, Eric A. E.; Erb, Judith L.; Downward, James G.; Priuska, Eric M.; Wittliff, James L.; Feng, Wenke; Magner, Joseph; Larsen, Gerald L.

    2001-03-01

    Between 1995 and 1997 over 62% of the counties in Minnesota reported the presence of malformed frogs. While most sites have recently shown a decline in malformed frog populations, one site in northeastern Minnesota with no prior history of containing malformed frogs was recently discovered to contain > 67% malformed Rana pipiens (northern leopard frogs). As part of an effort to study the presence of hormonally active agents in fresh water sources, water samples were collected from lakes in Minnesota containing malformed frogs and analyzed for the presence of hormonally active compounds using a novel evanescent field fluorometric biosensor and the frog embryo teratogenesis assay: Xenopus (FETAX) bioassay. The waveguide based biosensor developed by ThreeFold Sensors (TFS biosensor, Ann Arbor, MI) detects the presence of estrogenic compounds capable of interacting with free human ER-a and by inhibiting binding to an immobilized estrogen. The FETAX bioassay is a developmental assay, which measures teratogenicity, mortality, and inhibition of growth during the first 96 hours of organogenesis and thereby provides a universal screen for endocrine disruptors. TFS biosensor and FETAX screening of the water samples suggest a relationship between estrogenic activity, mineral supplementation, and the occurrence of malformed frogs.

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

    PubMed Central

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

    2013-01-01

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

  10. Games With a Purpose: Frog and the Lily Pads

    ERIC Educational Resources Information Center

    Sawicki, Timothy

    2005-01-01

    This article describes a game involving poly spots, frog bean bags, and a basket that can be used to assess locomotor activities, e.g., hopping and throwing, while also developing teamwork strategies and mathematical abilities.

  11. Frog tongue surface microstructures: functional and evolutionary patterns

    PubMed Central

    Gorb, Stanislav N

    2016-01-01

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

  12. Frog tongue surface microstructures: functional and evolutionary patterns.

    PubMed

    Kleinteich, Thomas; Gorb, Stanislav N

    2016-01-01

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

  13. Chytridiomycosis in dwarf African frogs Hymenochirus curtipes.

    PubMed

    Murphy, B G; Hillman, C; Groff, J M

    2015-05-11

    Chytridiomycosis, resulting from an infection with the fungal agent Batrachochytrium dendrobatidis (Bd), has resulted in widespread population declines in both wild and captive amphibians. The dwarf African frog (DAF) Hymenochirus curtipes is native to central Africa and is commonly sold throughout North America as an aquarium pet species. Here we document fatal chytridiomycosis resulting from cutaneous Bd infections in DAF purchased directly from a pet store and from a historical lethal epizootic occurring at an aquaculture facility in central California, USA, more than 25 yr ago. Histological lesions and PCR-amplified sequence data were consistent with the etiology of Bd. The potential epidemiological relevance of this infection in DAF is discussed. PMID:25958807

  14. Water relations of the burrowing sandhill frog, Arenophryne rotunda (Myobatrachidae).

    PubMed

    Cartledge, V A; Withers, P C; Thompson, G G; McMaster, K A

    2006-05-01

    Arenophryne rotunda is a small (2-8 g) terrestrial frog that inhabits the coastal sand dunes of central Western Australia. While sand burrowing is a strategy employed by many frog species inhabiting Australia's semi-arid and arid zones, A. rotunda is unique among burrowing species because it lives independently of free water and can be found nocturnally active on the dune surface for relatively extended periods. Consequently, we examined the physiological factors that enable this unique frog to maintain water balance. A. rotunda was not found to have any special adaptation to reduce EWL (being equivalent to a free water surface) or rehydrate from water (having the lowest rehydration rate measured for 15 Western Australian frog species), but it was able to maintain water balance in sand of very low moisture (1-2%). Frogs excavated in the field were in dune sand of 4.4% moisture content, as a consequence of recent rain, which was more than adequate for these frogs to maintain water balance as reflected by their low plasma and urine osmotic concentrations. We suggest that in dry periods of the year, A. rotunda can achieve positive water balance by cutaneous water uptake by burrowing deeper into the substrate to where the percent water content is greater than 1.5%. PMID:16315052

  15. Frog tongue acts as muscle-powered adhesive tape.

    PubMed

    Kleinteich, Thomas; Gorb, Stanislav N

    2015-09-01

    Frogs are well known to capture fast-moving prey by flicking their sticky tongues out of the mouth. This tongue projection behaviour happens extremely fast which makes frog tongues a biological high-speed adhesive system. The processes at the interface between tongue and prey, and thus the mechanism of adhesion, however, are completely unknown. Here, we captured the contact mechanics of frog tongues by filming tongue adhesion at 2000 frames per second through an illuminated glass. We found that the tongue rolls over the target during attachment. However, during the pulling phase, the tongue retractor muscle acts perpendicular to the target surface and thus prevents peeling during tongue retraction. When the tongue detaches, mucus fibrils form between the tongue and the target. Fibrils commonly occur in pressure-sensitive adhesives, and thus frog tongues might be a biological analogue to these engineered materials. The fibrils in frog tongues are related to the presence of microscopic papillae on the surface. Together with a layer of nanoscale fibres underneath the tongue epithelium, these surface papillae will make the tongue adaptable to asperities. For the first time, to the best of our knowledge, we are able to integrate anatomy and function to explain the processes during adhesion in frog tongues. PMID:26473054

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

    PubMed

    Zhang, Dian; Cui, Jianguo; Tang, Yezhong

    2012-01-01

    In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs) evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs. PMID:23029243

  17. Frog tongue acts as muscle-powered adhesive tape

    PubMed Central

    Kleinteich, Thomas; Gorb, Stanislav N.

    2015-01-01

    Frogs are well known to capture fast-moving prey by flicking their sticky tongues out of the mouth. This tongue projection behaviour happens extremely fast which makes frog tongues a biological high-speed adhesive system. The processes at the interface between tongue and prey, and thus the mechanism of adhesion, however, are completely unknown. Here, we captured the contact mechanics of frog tongues by filming tongue adhesion at 2000 frames per second through an illuminated glass. We found that the tongue rolls over the target during attachment. However, during the pulling phase, the tongue retractor muscle acts perpendicular to the target surface and thus prevents peeling during tongue retraction. When the tongue detaches, mucus fibrils form between the tongue and the target. Fibrils commonly occur in pressure-sensitive adhesives, and thus frog tongues might be a biological analogue to these engineered materials. The fibrils in frog tongues are related to the presence of microscopic papillae on the surface. Together with a layer of nanoscale fibres underneath the tongue epithelium, these surface papillae will make the tongue adaptable to asperities. For the first time, to the best of our knowledge, we are able to integrate anatomy and function to explain the processes during adhesion in frog tongues. PMID:26473054

  18. Delimiting Areas of Endemism through Kernel Interpolation

    PubMed Central

    Oliveira, Ubirajara; Brescovit, Antonio D.; Santos, Adalberto J.

    2015-01-01

    We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE), based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units. PMID:25611971

  19. Microsatellite marker development by multiplex ion torrent PGM sequencing: a case study of the endangered Odorrana narina complex of frogs.

    PubMed

    Igawa, Takeshi; Nozawa, Masafumi; Nagaoka, Mai; Komaki, Shohei; Oumi, Shohei; Fujii, Tamotsu; Sumida, Masayuki

    2015-01-01

    The endangered Ryukyu tip-nosed frog Odorrana narina and its related species, Odorrana amamiensis, Odorrana supranarina, and Odorrana utsunomiyaorum, belong to the family Ranidae and are endemically distributed in Okinawa (O. narina), Amami and Tokunoshima (O. amamiensis), and Ishigaki and Iriomote (O. supranarina and O. utsunomiyaorum) Islands. Because of varying distribution patterns, this species complex is an intrinsic model for speciation and adaptation. For effective conservation and molecular ecological studies, further genetic information is needed. For rapid, cost-effective development of several microsatellite markers for these and 2 other species, we used next-generation sequencing technology of Ion Torrent PGM™. Distribution patterns of repeat motifs of microsatellite loci in these modern frog species (Neobatrachia) were similarly skewed. We isolated and characterized 20 new microsatellite loci of O. narina and validated cross-amplification in the three-related species. Seventeen, 16, and 13 loci were cross-amplified in O. amamiensis, O. supranarina, and O. utsunomiyaorum, respectively, reflecting close genetic relationships between them. Mean number of alleles and expected heterozygosity of newly isolated loci varied depending on the size of each inhabited island. Our findings suggested the suitability of Ion Torrent PGM™ for microsatellite marker development. The new markers developed for the O. narina complex will be applicable in conservation genetics and molecular ecological studies. PMID:25425674

  20. Species delimitation, phylogeny and evolutionary demography of co-distributed, montane frogs in the southern Brazilian Atlantic Forest.

    PubMed

    Firkowski, Carina R; Bornschein, Marcos R; Ribeiro, Luiz F; Pie, Marcio R

    2016-07-01

    The Brazilian Atlantic Forest (BAF) is recognized as one of the world's biodiversity hotspots, with even more species per unit of area than the Amazon, however the mechanisms that led to such astonishing diversity are yet to be fully understood. In this study, we investigate the diversification of two co-distributed frog genera associated with montane areas of southern BAF: Melanophryniscus (Bufonidae) and Brachycephalus (Brachycephalidae). Species delimitation methods using mitochondrial and nuclear loci supported the existence of a remarkable number of highly endemic species in each genus, most of which occupy only one or a few adjacent mountaintops. Their timing of diversification was highly congruent, supporting recent speciation events within the past 600 thousand years. Extended Bayesian skyline plots indicate that most populations have remained relatively stable in size across the evolutionary past, with recent growth after 0.15My, suggesting that the drastic changes found in previous studies on lowland frog species were not shared by these montane taxa. These results are consistent with the existence of a montane refugium in southern BAF, allowing species persistence through the climatic shifts experienced along the BAF during the Quaternary. PMID:27129900

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  3. Environmental Monitoring of Endemic Cholera

    NASA Astrophysics Data System (ADS)

    ElNemr, W.; Jutla, A. S.; Constantin de Magny, G.; Hasan, N. A.; Islam, M.; Sack, R.; Huq, A.; Hashem, F.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat. Since Vibrio cholerae, the causative agent of the disease, is autochthonous to riverine, estuarine, and coastal waters, it is unlikely the bacteria can be eradicated from its natural habitat. Prediction of disease, in conjunction with preventive vaccination can reduce the prevalence rate of a disease. Understanding the influence of environmental parameters on growth and proliferation of bacteria is an essential first step in developing prediction methods for outbreaks. Large scale geophysical variables, such as SST and coastal chlorophyll, are often associated with conditions favoring growth of V. cholerae. However, local environmental factors, meaning biological activity in ponds from where the bulk of populations in endemic regions derive water for daily usage, are either neglected or oversimplified. Using data collected from several sites in two geographically distinct locations in South Asia, we have identified critical local environmental factors associated with cholera outbreak. Of 18 environmental variables monitored for water sources in Mathbaria (a coastal site near the Bay of Bengal) and Bakergonj (an inland site) of Bangladesh, water depth and chlorophyll were found to be important factors associated with initiation of cholera outbreaks. Cholera in coastal regions appears to be related to intrusion. However, monsoonal flooding creates conditions for cholera epidemics in inland regions. This may be one of the first attempts to relate in-situ environmental observations with cholera. We anticipate that it will be useful for further development of prediction models in the resource constrained regions.

  4. Shifts in Species Interactions Due to the Evolution of Functional Differences between Endemics and Non-Endemics: An Endemic Syndrome Hypothesis

    PubMed Central

    Gorman, Courtney E.; Potts, Brad M.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2014-01-01

    Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change. PMID:25340402

  5. Shifts in species interactions due to the evolution of functional differences between endemics and non-endemics: an endemic syndrome hypothesis.

    PubMed

    Gorman, Courtney E; Potts, Brad M; Schweitzer, Jennifer A; Bailey, Joseph K

    2014-01-01

    Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change. PMID:25340402

  6. Resurrecting an Extinct Species: Archival DNA, Taxonomy, and Conservation of the Vegas Valley Leopard Frog

    EPA Science Inventory

    Suggestions that the extinct Vegas Valley leopard frog (Rana fisheri = Lithobates fisheri) may have been synonymous with one of several declining species has complicated recovery planning for imperiled leopard frogs in southwestern North America. To address this concern, we recon...

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

    USGS Publications Warehouse

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

    2002-01-01

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

  8. Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii).

    PubMed

    Archibald, Kate E; Minter, Larry J; Dombrowski, Daniel S; O'Brien, Jodi L; Lewbart, Gregory A

    2015-03-01

    The waxy monkey frog (Phyllomedusa sauvagii) is an arboreal amphibian native to arid regions of South America, and it has developed behavioral and physiologic adaptations to permit survival in dry environments. These adaptations include a uricotelic nitrogen metabolism and unique cutaneous lipid excretions to prevent evaporative water loss. Uroliths are a rare finding in amphibians. Six adult, presumed wild-caught waxy monkey frogs housed in a museum animal collection were diagnosed with cystic urolithiasis over a 7-yr period, and a single animal was diagnosed with four recurrent cases. Six cases were identified incidentally at routine physical or postmortem examination and four cases were identified during veterinary evaluation for coelomic distension, lethargy, anorexia, and increased soaking behavior. Calculi were surgically removed from three frogs via cystotomy, and a single frog underwent three cystotomies and two cloacotomies for recurrent urolithiasis. Two frogs died within the 24-hr postoperative period. Two representative calculi from a single frog were submitted for component analysis and found to consist of 100% ammonium urate. In the present report, cystic calculi are proposed to be the result of a high-protein diet based on a single invertebrate source, coupled with uricotelism, dehydration, increased cutaneous water loss, body temperature fluctuations facilitating supersaturation of urine, and subsequent accumulation and precipitation of urogenous wastes within the urinary bladder. Surgical cystotomy represents a short-term treatment strategy for this condition. Preventative measures, such as supplying a diversified and balanced diet in addition to environmental manipulation aimed at promoting adequate hydration, are anticipated to be more-rewarding management tools for cystic urolithiasis in the waxy monkey frog. PMID:25831582

  9. Panamanian frog species host unique skin bacterial communities

    PubMed Central

    Belden, Lisa K.; Hughey, Myra C.; Rebollar, Eria A.; Umile, Thomas P.; Loftus, Stephen C.; Burzynski, Elizabeth A.; Minbiole, Kevin P. C.; House, Leanna L.; Jensen, Roderick V.; Becker, Matthew H.; Walke, Jenifer B.; Medina, Daniel; Ibáñez, Roberto; Harris, Reid N.

    2015-01-01

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

  10. Panamanian frog species host unique skin bacterial communities.

    PubMed

    Belden, Lisa K; Hughey, Myra C; Rebollar, Eria A; Umile, Thomas P; Loftus, Stephen C; Burzynski, Elizabeth A; Minbiole, Kevin P C; House, Leanna L; Jensen, Roderick V; Becker, Matthew H; Walke, Jenifer B; Medina, Daniel; Ibáñez, Roberto; Harris, Reid N

    2015-01-01

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

  11. Saliva Crystallization Occurs in Female Bornean Orangutans (Pongo pygmaeus): Could It Be a New Option for Monitoring of Menstrual Cycle in Captive Great Apes?

    PubMed

    Kubátová, Anna; Fedorova, Tamara

    2016-01-01

    Saliva crystallization was previously studied in both humans and animals with various results. The study aimed to confirm of the presence of saliva crystallization in female Bornean orangutans (Pongo pygmaeus), to evaluate the quality of samples which were collected from animals and processed by keepers, and to test preliminarily if the saliva crystallization could be connected with menstrual cycle and could serve as a cheap, quick and simple method for the basic monitoring of their reproductive status. The research was carried out from September 2014 to January 2015. Sampling of saliva was done in three female orangutans from three zoological gardens (Dvur Kralove, Usti nad Labem, Bojnice) daily, mostly by tongue prints on glass slides with ground edges or by sampling directly from the mouth using plastic spoons from which the saliva was transferred onto glass slides. Samples were evaluated by light microscopy with ×400 magnification. The quality of the sample and type of crystallization was assessed for two different approaches. In total, 246 samples were evaluated. We confirmed the presence of saliva crystallization in orangutans. The quality of samples was variable however acceptable. Unfortunately, it was impossible to detect exact fertile period in two females. However in one orangutan female, when the crystallization was evaluated by the approach typically used in humans, we discovered that saliva crystallization during the fertile period significantly differed from saliva crystallization in the non-fertile period. This points out the possibility of using saliva crystallization for detection of the fertile period in orangutans. However, further research was recommended. PMID:27458728

  12. Understanding the Impacts of Land-Use Policies on a Threatened Species: Is There a Future for the Bornean Orang-utan?

    PubMed Central

    Wich, Serge A.; Gaveau, David; Abram, Nicola; Ancrenaz, Marc; Baccini, Alessandro; Brend, Stephen; Curran, Lisa; Delgado, Roberto A.; Erman, Andi; Fredriksson, Gabriella M.; Goossens, Benoit; Husson, Simon J.; Lackman, Isabelle; Marshall, Andrew J.; Naomi, Anita; Molidena, Elis; Nardiyono; Nurcahyo, Anton; Odom, Kisar; Panda, Adventus; Purnomo; Rafiastanto, Andjar; Ratnasari, Dessy; Santana, Adi H.; Sapari, Imam; van Schaik, Carel P.; Sihite, Jamartin; Spehar, Stephanie; Santoso, Eddy; Suyoko, Amat; Tiju, Albertus; Usher, Graham; Atmoko, Sri Suci Utami; Willems, Erik P.; Meijaard, Erik

    2012-01-01

    The geographic distribution of Bornean orang-utans and its overlap with existing land-use categories (protected areas, logging and plantation concessions) is a necessary foundation to prioritize conservation planning. Based on an extensive orang-utan survey dataset and a number of environmental variables, we modelled an orang-utan distribution map. The modelled orang-utan distribution map covers 155,106 km2 (21% of Borneo's landmass) and reveals four distinct distribution areas. The most important environmental predictors are annual rainfall and land cover. The overlap of the orang-utan distribution with land-use categories reveals that only 22% of the distribution lies in protected areas, but that 29% lies in natural forest concessions. A further 19% and 6% occurs in largely undeveloped oil palm and tree plantation concessions, respectively. The remaining 24% of the orang-utan distribution range occurs outside of protected areas and outside of concessions. An estimated 49% of the orang-utan distribution will be lost if all forest outside of protected areas and logging concessions is lost. To avoid this potential decline plantation development in orang-utan habitats must be halted because it infringes on national laws of species protection. Further growth of the plantation sector should be achieved through increasing yields in existing plantations and expansion of new plantations into areas that have already been deforested. To reach this goal a large scale island-wide land-use masterplan is needed that clarifies which possible land uses and managements are allowed in the landscape and provides new standardized strategic conservation policies. Such a process should make much better use of non-market values of ecosystem services of forests such as water provision, flood control, carbon sequestration, and sources of livelihood for rural communities. Presently land use planning is more driven by vested interests and direct and immediate economic gains, rather than by

  13. California Rare Endemics and Climate Change

    NASA Astrophysics Data System (ADS)

    Espinoza, M.

    2010-12-01

    California is known for its wide variety of endemic flora, from its annuals such as the Eschscholzia californica (California poppy) to the perennials like the Arctostaphylos pallida (Alameda manzanita), which happens to be a rare species. Each species plays an important role in the biodiversity of California, yet there are species that are threatened, not only by human interaction and urbanization, but by climate change. Species that we seldom see are now on the verge of becoming eradicated; rare endemics similar to Arctostaphylos pallida are now facing a new challenge that may severely impair their survival. The climate has changed significantly over the twentieth century and it has affected the distribution of rare endemics in California, both geographically as well as within their climatic and edaphic niches. Lilaeopsis masonii is just one rare endemic, however it serves as a representative of the other 23 species that were studied. Using Maxent, a climate-modeling program, it was viable to construct two climate envelopes of the masonii species: the early century envelope (1930-1959) and the later century envelope (1990-2009). When these two climate envelopes were compared, it became clear that the later century climate envelope had contracted radically, reshaping the climate niche of all rare endemics in California due to an increase in temperature. It is possible to conclude that the future of rare endemics hangs in the balance, where one degree higher in temperature is enough to topple the scale.

  14. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  15. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  16. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  17. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  18. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  19. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  20. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  1. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  2. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  3. 75 FR 8733 - Least Chub and Columbia Spotted Frog Candidate Conservation Agreement With Assurances; Receipt of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ... Fish and Wildlife Service Least Chub and Columbia Spotted Frog Candidate Conservation Agreement With... (CCAA) for the least chub (Iotichthys phlegethontis) and Columbia spotted frog (Rana lutreiventris..., least chub and Columbia spotted frog inhabited a variety of aquatic habitat types throughout...

  4. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  5. The Funeral of Froggy the Frog: The Child as Dramatist, Designer, and Realist

    ERIC Educational Resources Information Center

    Cummins, Lauren

    2004-01-01

    One sunny afternoon, six-year-old Zachary and his friend John Michael, four and a half, discovered a dead frog in a bag of clay in the garage. Zachary proposed, "Let's have a funeral for the frog." This is how the funeral drama of Froggy the Frog began. This article describes the play experiences of Zachary and John Michael as designers,…

  6. Tourism and the Conservation of Critically Endangered Frogs

    PubMed Central

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

    2012-01-01

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

  7. Drainage ditches facilitate frog movements in a hostile landscape

    USGS Publications Warehouse

    Mazerolle, M.J.

    2005-01-01

    Ditches are common in landscapes influenced by agricultural, forestry, and peat mining activities, and their value as corridors remains unassessed. Pond-breeding amphibians can encounter hostile environments when moving between breeding, summering, or hibernation sites, and are likely to benefit from the presence of ditches in the landscape. Within a system consisting of ditch networks in bogs mined for peat in eastern New Brunswick, Canada, I quantified the breeding, survival, and movements of green frogs (Rana clamitans melanota) in drainage ditches and also surveyed peat fields. Frogs rarely ventured on peat fields and most individuals frequented drainage ditches containing water, particularly in late summer. Though frogs did not breed in ditches, their survival rate in ditches was high (88%). Ditches did not hinder frog movements, as frogs moved independently of the current. Results indicate that drainage ditches containing water enable some movements between habitats isolated by peat mining, in contrast to peat surfaces, and suggest they function as amphibian movement corridors. Thus, such drainage ditches may mitigate the effects of peat extraction on amphibian populations. At the very least, these structures provide an alternative to hostile peat surfaces. This study highlights that small-scale corridors are potentially valuable in population dynamics. ?? Springer 2005.

  8. Intersexuality and the Cricket Frog Decline: Historic and Geographic Trends

    PubMed Central

    Reeder, Amy L.; Ruiz, Marilyn O.; Pessier, Allan; Brown, Lauren E.; Levengood, Jeffrey M.; Phillips, Christopher A.; Wheeler, Matthew B.; Warner, Richard E.; Beasley, Val R.

    2005-01-01

    Exposure to anthropogenic endocrine disruptors has been listed as one of several potential causes of amphibian declines in recent years. We examined gonads of 814 cricket frogs (Acris crepitans) collected in Illinois and deposited in museum collections to elucidate relationships between the decline of this species in Illinois and the spatial and temporal distribution of individuals with intersex gonads. Compared with the preorganochlorine era studied (1852–1929), the percentage of intersex cricket frogs increased during the period of industrial growth and initial uses of polychlorinated biphenyls (PCBs) (1930–1945), was highest during the greatest manufacture and use of p,p-dichlorodiphenyltrichloroethane (DDT) and PCBs (1946–1959), began declining with the increase in public concern and environmental regulations that reduced and then prevented sales of DDT in the United States (1960–1979), and continued to decline through the period of gradual reductions in environmental residues of organochlorine pesticides and PCBs in the midwestern United States (1980–2001). The proportion of intersex individuals among those frogs was highest in the heavily industrialized and urbanized northeastern portion of Illinois, intermediate in the intensively farmed central and northwestern areas, and lowest in the less intensively managed and ecologically more diverse southern part of the state. Records of deposits of cricket frog specimens into museum collections indicate a marked reduction in numbers from northeastern Illinois in recent decades. These findings are consistent with the hypothesis that endocrine disruption contributed to the decline of cricket frogs in Illinois. PMID:15743712

  9. Tourism and the conservation of critically endangered frogs.

    PubMed

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

    2012-01-01

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

  10. Projection structure of frog rhodopsin in two crystal forms.

    PubMed Central

    Schertler, G F; Hargrave, P A

    1995-01-01

    Rhodopsin is the G protein-coupled receptor that upon light activation triggers the visual transduction cascade. Rod cell outer segment disc membranes were isolated from dark-adapted frog retinas and were extracted with Tween detergents to obtain two-dimensional rhodopsin crystals for electron crystallography. When Tween 80 was used, tubular structures with a p2 lattice (a = 32 A, b = 83 A, gamma = 91 degrees) were formed. The use of a Tween 80/Tween 20 mixture favored the formation of larger p22(1)2(1) lattices (a = 40 A, b = 146 A, gamma = 90 degrees). Micrographs from frozen hydrated frog rhodopsin crystals were processed, and projection structures to 7-A resolution for the p22(1)2(1) form and to 6-A resolution for the p2 form were calculated. The maps of frog rhodopsin in both crystal forms are very similar to the 9-A map obtained previously for bovine rhodopsin and show that the arrangement of the helices is the same. In a tentative topographic model, helices 4, 6, and 7 are nearly perpendicular to the plane of the membrane. In the higher-resolution projection maps of frog rhodopsin, helix 5 looks more tilted than it appeared previously. The quality of the two frog rhodopsin crystals suggests that they would be suitable to obtain a three-dimensional structure in which all helices would be resolved. Images Fig. 1 Fig. 2 Fig. 6 PMID:8524807

  11. Whether the weather drives patterns of endemic amphibian chytridiomycosis: a pathogen proliferation approach.

    PubMed

    Murray, Kris A; Skerratt, Lee F; Garland, Stephen; Kriticos, Darren; McCallum, Hamish

    2013-01-01

    The pandemic amphibian disease chytridiomycosis often exhibits strong seasonality in both prevalence and disease-associated mortality once it becomes endemic. One hypothesis that could explain this temporal pattern is that simple weather-driven pathogen proliferation (population growth) is a major driver of chytridiomycosis disease dynamics. Despite various elaborations of this hypothesis in the literature for explaining amphibian declines (e.g., the chytrid thermal-optimum hypothesis) it has not been formally tested on infection patterns in the wild. In this study we developed a simple process-based model to simulate the growth of the pathogen Batrachochytrium dendrobatidis (Bd) under varying weather conditions to provide an a priori test of a weather-linked pathogen proliferation hypothesis for endemic chytridiomycosis. We found strong support for several predictions of the proliferation hypothesis when applied to our model species, Litoria pearsoniana, sampled across multiple sites and years: the weather-driven simulations of pathogen growth potential (represented as a growth index in the 30 days prior to sampling; GI30) were positively related to both the prevalence and intensity of Bd infections, which were themselves strongly and positively correlated. In addition, a machine-learning classifier achieved ~72% success in classifying positive qPCR results when utilising just three informative predictors 1) GI30, 2) frog body size and 3) rain on the day of sampling. Hence, while intrinsic traits of the individuals sampled (species, size, sex) and nuisance sampling variables (rainfall when sampling) influenced infection patterns obtained when sampling via qPCR, our results also strongly suggest that weather-linked pathogen proliferation plays a key role in the infection dynamics of endemic chytridiomycosis in our study system. Predictive applications of the model include surveillance design, outbreak preparedness and response, climate change scenario modelling and

  12. A perchlorate sensitive iodide transporter in frogs

    PubMed Central

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

    2008-01-01

    Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater 125I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na+/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na+-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na+/iodide symporter in Xenopus laevis, as well as Rana catesbeiana. PMID:18275962

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

    PubMed

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

    2010-09-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was unknown. To determine the presence and prevalence of Bd on PEI, skin swabs were collected from 115 frogs from 18 separate sites across the province during the summer of 2009. The swabs were tested through single round end-point PCR for the presence of Bd DNA. Thirty-one frogs were positive, including 25/93 (27%) green frogs Lithobates (Rana) clamitans, 5/20 (25%) northern leopard frogs L. (R.) pipiens, and 1/2 (50%) wood frogs L. sylvaticus (formerly R. sylvatica); 12 of the 18 (67%) sites had at least 1 positive frog. The overall prevalence of Bd infection was estimated at 26.9% (7.2-46.7%, 95% CI). Prevalence amongst green frogs and leopard frogs was similar, but green frogs had a stronger PCR signal when compared to leopard frogs, regardless of age (p < 0.001) and body length (p = 0.476). Amongst green frogs, juveniles were more frequently positive than adults (p = 0.001). Green frogs may be the most reliable species to sample when looking for Bd in eastern North America. The 1 wood frog positive for Bd was found dead from chytridiomycosis; none of the other frogs that were positive for Bd by PCR showed any obvious signs of illness. Further monitoring will be required to determine what effect Bd infection has on amphibian population health on PEI. PMID:21387987

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

    PubMed

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

    2013-01-01

    Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad. PMID:24086297

  15. Sticking under Wet Conditions: The Remarkable Attachment Abilities of the Torrent Frog, Staurois guttatus

    PubMed Central

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

    2013-01-01

    Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad. PMID:24086297

  16. Prevalence and intensity of Alaria alata (Goeze, 1792) in water frogs and brown frogs in natural conditions.

    PubMed

    Patrelle, Cécile; Portier, Julien; Jouet, Damien; Delorme, Daniel; Ferté, Hubert

    2015-12-01

    In the last 15 years, the mesocercariae of Alaria alata have frequently been reported in the wild boar during routine Trichinella inspections made compulsory for the trade of venison meat in Europe. If these studies have focused primarily on mesocercariae isolated from meat, few works have been done so far to understand the circulation of the parasite in natural conditions especially in the intermediate hosts. This study focuses on the second intermediate hosts of this parasite assessing the suitability of two amphibian groups-brown frogs and water frogs sensu lato-for mesocercarial infection on an area where A. alata has already been identified in water snails and wild boars. During this study, both groups showed to be suitable for mesocercarial infection, with high prevalence and parasite burdens. Prevalence was higher in the brown frog group (56.9 versus 11.54 % for water frogs) which would indicate that it is a preferential group for infection on the study area, though reasons for this remain to be investigated. No significant difference among prevalences was observed between tadpoles and frogs. This study, the first focusing on A. alata in these amphibians in Europe, provides further information on circulation of this parasite in natura. PMID:26319522

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

    PubMed Central

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

    2015-01-01

    The formation of proper sensory afferent connections during development is essential for brain function. Activity-based competition is believed to drive ocular dominance columns (ODC) in mammals and in experimentally-generated three-eyed frogs. ODC formation is thus a compromise of activity differences between two eyes and similar molecular cues. To gauge the generality of graphical map formation in the brain, we investigated the inner ear projection, known for its well-defined and early segregation of afferents from vestibular and auditory endorgans. In analogy to three eyed-frogs, we generated three-eared frogs to assess to what extent vestibular afferents from two adjacent ears could segregate. Donor ears were transplanted either in the native orientation or rotated by 90 degrees. These manipulations should result in either similar or different induced activity between both ears, respectively. Three-eared frogs with normal orientation showed normal swimming whereas those with a rotated third ear showed aberrant behaviors. Projection studies revealed that only afferents from the rotated ears segregated from those from the native ear within the vestibular nucleus, resembling the ocular dominance columns formed in three-eyed frogs. Vestibular segregation suggests that mechanisms comparable to those operating in the ODC formation of the visual system may act on vestibular projection refinements. PMID:25661240

  18. Niche conservatism in Gynandropaa frogs on the southeastern Qinghai-Tibetan Plateau

    PubMed Central

    Hu, Junhua; Broennimann, Olivier; Guisan, Antoine; Wang, Bin; Huang, Yan; Jiang, Jianping

    2016-01-01

    The role of ecological niche in lineage diversification has been the subject of long-standing interest of ecologists and evolutionary biologists. Gynandropaa frogs diversified into three independent clades endemic to the southeastern Qinghai-Tibetan Plateau. Here, we address the question whether these clades kept the same niche after separation, and what it tells us about possible diversification processes. We applied predictions in geographical (G)-space and tests of niche conservatism in environmental (E)-space. Niche models in G-space indicate separate regions with high suitability for the different clades, with some potential areas of sympatry. While the pair of central and eastern clades displayed the largest niche overlap for most variables, and strict niche equivalency was rejected for all clade-pairs, we found no strong evidence for niche divergence, but rather the signature of niche conservatism compared to null models in E-space. These results suggest a common ancestral ecological niche, and as such give good support to divergence through allopatric speciation, but alternative explanations are also possible. Our findings illustrate how testing for niche conservatism in lineage diversification can provide insights into underlying speciation processes, and how this information may guide further research and conservation practices, as illustrated here for amphibians on the Qinghai-Tibetan Plateau. PMID:27601098

  19. Niche conservatism in Gynandropaa frogs on the southeastern Qinghai-Tibetan Plateau.

    PubMed

    Hu, Junhua; Broennimann, Olivier; Guisan, Antoine; Wang, Bin; Huang, Yan; Jiang, Jianping

    2016-01-01

    The role of ecological niche in lineage diversification has been the subject of long-standing interest of ecologists and evolutionary biologists. Gynandropaa frogs diversified into three independent clades endemic to the southeastern Qinghai-Tibetan Plateau. Here, we address the question whether these clades kept the same niche after separation, and what it tells us about possible diversification processes. We applied predictions in geographical (G)-space and tests of niche conservatism in environmental (E)-space. Niche models in G-space indicate separate regions with high suitability for the different clades, with some potential areas of sympatry. While the pair of central and eastern clades displayed the largest niche overlap for most variables, and strict niche equivalency was rejected for all clade-pairs, we found no strong evidence for niche divergence, but rather the signature of niche conservatism compared to null models in E-space. These results suggest a common ancestral ecological niche, and as such give good support to divergence through allopatric speciation, but alternative explanations are also possible. Our findings illustrate how testing for niche conservatism in lineage diversification can provide insights into underlying speciation processes, and how this information may guide further research and conservation practices, as illustrated here for amphibians on the Qinghai-Tibetan Plateau. PMID:27601098

  20. Myxosporean parasites in Australian frogs: Importance, implications and future directions

    PubMed Central

    Hartigan, Ashlie; Phalen, David N.; Šlapeta, Jan

    2013-01-01

    Myxosporean parasites have been identified in amphibians around the world yet very little is known about their diversity, biology and host impact. Several species of Australian frogs have recently been shown to be affected by myxosporidiosis caused by two new Cystodiscus species. In this manuscript, we review what is known about the myxosporean parasites Cystodiscus australis and Cystodiscus axonis that produce myxospores in gallbladders of Australian frogs and Myxobolus fallax and Myxobolus hylae that produce spores in gonads and the potential impact of these parasites on the conservation of Australian frogs. By doing so, we aim to highlight the importance of amphibian myxosporean parasites, suggest directions for future research and argue that the lessons learned about these parasites in Australia are directly transferable to amphibians around the world. PMID:24533318

  1. Gnathostomiasis in frog-eating snakes from Japan.

    PubMed

    Ishiwata, K; Nakao, H; Nose, R; Komiya, M; Hanada, S; Enomoto, Y; Nawa, Y

    1997-10-01

    Gnathostoma doloresi parasitizes the gastric wall of wild (boars) and domestic (pigs) swine (Sus scrofa). Its larvae cause cutaneous larva migrans in humans. Amphibians, reptiles and a freshwater fish are infected with the advanced 3rd stage larvae. Prevalence of G. doloresi larvae were surveyed in several snakes, especially in a common frog-eating snake (Rhabdophis tigrinus). All species of snakes examined were infected with G. doloresi larvae suggesting that snakes are important reservoir hosts. Prevalence of G. doloresi larvae in frog-eating snakes was lower than that found in mammal-eating snakes. Thus, as a source of infection to snakes, small mammals may be more important than frogs in the natural life cycle of G. doloresi in Japan. PMID:9391975

  2. Unfertilized frog eggs die by apoptosis following meiotic exit

    PubMed Central

    2011-01-01

    Background A characteristic feature of frog reproduction is external fertilization accomplished outside the female's body. Mature fertilization-competent frog eggs are arrested at the meiotic metaphase II with high activity of the key meiotic regulators, maturation promoting factor (MPF) and cytostatic factor (CSF), awaiting fertilization. If the eggs are not fertilized within several hours of ovulation, they deteriorate and ultimately die by as yet unknown mechanism. Results Here, we report that the vast majority of naturally laid unfertilized eggs of the African clawed frog Xenopus laevis spontaneously exit metaphase arrest under various environmental conditions and degrade by a well-defined apoptotic process within 48 hours after ovulation. The main features of this process include cytochrome c release, caspase activation, ATP depletion, increase of ADP/ATP ratio, apoptotic nuclear morphology, progressive intracellular acidification, and egg swelling. Meiotic exit seems to be a prerequisite for execution of the apoptotic program, since (i) it precedes apoptosis, (ii) apoptotic events cannot be observed in the eggs maintaining high activity of MPF and CSF, and (iii) apoptosis in unfertilized frog eggs is accelerated upon early meiotic exit. The apoptotic features cannot be observed in the immature prophase-arrested oocytes, however, the maturation-inducing hormone progesterone renders oocytes susceptible to apoptosis. Conclusions The study reveals that naturally laid intact frog eggs die by apoptosis if they are not fertilized. A maternal apoptotic program is evoked in frog oocytes upon maturation and executed after meiotic exit in unfertilized eggs. The meiotic exit is required for execution of the apoptotic program in eggs. The emerging anti-apoptotic role of meiotic metaphase arrest needs further investigation. PMID:22195698

  3. Lizard and Frog Prestin: Evolutionary Insight into Functional Changes

    PubMed Central

    Tang, Jie; Pecka, Jason L.; Fritzsch, Bernd

    2013-01-01

    The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC), the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken’s and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired. PMID:23342145

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

    PubMed

    Tang, Jie; Pecka, Jason L; Fritzsch, Bernd; Beisel, Kirk W; He, David Z Z

    2013-01-01

    The plasma membrane of mammalian cochlear outer hair cells contains prestin, a unique motor protein. Prestin is the fifth member of the solute carrier protein 26A family. Orthologs of prestin are also found in the ear of non-mammalian vertebrates such as zebrafish and chicken. However, these orthologs are electrogenic anion exchangers/transporters with no motor function. Amphibian and reptilian lineages represent phylogenic branches in the evolution of tetrapods and subsequent amniotes. Comparison of the peptide sequences and functional properties of these prestin orthologs offer new insights into prestin evolution. With the recent availability of the lizard and frog genome sequences, we examined amino acid sequence and function of lizard and frog prestins to determine how they are functionally and structurally different from prestins of mammals and other non-mammals. Somatic motility, voltage-dependent nonlinear capacitance (NLC), the two hallmarks of prestin function, and transport capability were measured in transfected human embryonic kidney cells using voltage-clamp and radioisotope techniques. We demonstrated that while the transport capability of lizard and frog prestin was compatible to that of chicken prestin, the NLC of lizard prestin was more robust than that of chicken's and was close to that of platypus. However, unlike platypus prestin which has acquired motor capability, lizard or frog prestin did not demonstrate motor capability. Lizard and frog prestins do not possess the same 11-amino-acid motif that is likely the structural adaptation for motor function in mammals. Thus, lizard and frog prestins appear to be functionally more advanced than that of chicken prestin, although motor capability is not yet acquired. PMID:23342145

  5. Genetic and developmental studies of albino chorus frogs

    USGS Publications Warehouse

    Corn, Paul Stephen

    1986-01-01

    Albino (amelanic) adult chorus frogs (Pseudacris triseriata) occurred with frequencies of 7 percent in 1981 and 12 percent in 1982 in breeding aggregations at a pond in the foothills of the Colorado Front Range. Laboratory matings and examination of albino egg masses suggest that the absence of melanin is due to a recessive allele. The albino phenotype displayed no deficiencies in survival of embryos, rates of embryo or larval development, or rates of growth of juvenile frogs. The absence of abnormalities in development or growth suggests that the a allele in P. triseriata has an action different from albino alleles studied previously in anurans.

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

    PubMed Central

    Kumar, Vineeth T.V.; Holthausen, David; Jacob, Joshy; George, Sanil

    2015-01-01

    Host defense peptides (HDPs) are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs. PMID:27025618

  7. Divergence among barking frogs (Eleutherodactylus augusti) in the southwestern United States

    USGS Publications Warehouse

    Goldberg, C.S.; Sullivan, B.K.; Malone, J.H.; Schwalbe, C.R.

    2004-01-01

    Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

  8. Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

    PubMed

    McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

    2016-06-01

    Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey. PMID:27318689

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

    PubMed Central

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

    2013-01-01

    Males of all reed frog species (Anura: Hyperoliidae) have a prominent, often colourful, gular patch on their vocal sac, which is particularly conspicuous once the vocal sac is inflated. Although the presence, shape, and form of the gular patch are well-known diagnostic characters for these frogs, its function remains unknown. By integrating biochemical and histological methods, we found strong evidence that the gular patch is a gland producing volatile compounds, which might be emitted while calling. Volatile compounds were confirmed by gas chromatography–mass spectrometry in the gular glands in 11 species of the hyperoliid genera Afrixalus, Heterixalus, Hyperolius, and Phlyctimantis. Comparing the gular gland contents of 17 specimens of four sympatric Hyperolius species yielded a large variety of 65 compounds in species-specific combinations. We suggest that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice. PMID:24277973

  10. Landscape genetics of high mountain frog metapopulations

    USGS Publications Warehouse

    Murphy, M.A.; Dezzani, R.; Pilliod, D.S.; Storfer, A.

    2010-01-01

    Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between-site (landscape resistance) landscape characteristics and at-site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between-site and at-site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at-site landscape process) and resistance (e.g. between-site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at-site) and topographic complexity (between-site). Conversely, site productivity (as measured by heat load index, at-site) and growing season (as measured by frost-free period between-sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source-sink dynamics. In conclusion, gravity models provide a

  11. Mechanical Properties of the Frog Sarcolemma

    PubMed Central

    Fields, R. Wayne

    1970-01-01

    The elastic properties of cylindrical segments of sarcolemma were studied in single striated fibers of the frog semitendinosus muscle. All measurements were made on membranes of retraction zones, cell segments from which the sarcoplasm had retracted. Quantitative morphological studies indicated that three deforming forces interact with the intrinsic elastic properties of the sarcolemma to determine membrane configuration in retraction zone segments. The three deforming forces, namely intrazone pressure, axial fiber loads, and radial stresses introduced by retracted cell contents, could all be experimentally removed, permitting determination of the “undeformed” configuration of the sarcolemma. Analysis of these results indicated that membrane of intact fibers at rest length is about four times as wide and two-thirds as long as undeformed membrane. Membrane geometry was also studied as a function of internal hydrostatic pressure and axial loading to permit calculation of the circumferential and longitudinal tension-strain (T-S) diagrams. The sarcolemma exhibited nonlinear T-S properties concave to the tension axis in both directions. Circumferential T-S slopes (measures of membrane stiffness) ranged from 1500 to greater than 50,000 dynes/cm over the range of deformations investigated, while longitudinal T-S slopes varied from 23,000 to 225,000 dynes/cm. Thus, the membrane is anisotropic, being much stiffer in the longitudinal direction. Certain ramifications of the present results are discussed in relation to previous biomechanical studies of the sarcolemma and of other tissues. ImagesFigure 2Figure 3Figure 4 PMID:5439320

  12. Landscape genetics of high mountain frog metapopulations.

    PubMed

    Murphy, Melanie A; Dezzani, R; Pilliod, D S; Storfer, A

    2010-09-01

    Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between-site (landscape resistance) landscape characteristics and at-site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between-site and at-site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at-site landscape process) and resistance (e.g. between-site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at-site) and topographic complexity (between-site). Conversely, site productivity (as measured by heat load index, at-site) and growing season (as measured by frost-free period between-sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source-sink dynamics. In conclusion, gravity models provide a

  13. Firearm injuries: epidemic then, endemic now.

    PubMed

    Christoffel, Katherine Kaufer

    2007-04-01

    There has been a transition in US firearm injuries from an epidemic phase (mid-1980s to early 1990s) to an endemic one (since the mid-1990s). Endemic US firearm injuries merit public health attention because they exact an ongoing toll, may give rise to new epidemic outbreaks, and can foster firearm injuries in other parts of the world. The endemic period is a good time for the development of ongoing prevention approaches, including assessment and monitoring of local risk factors over time and application of proven measures to reduce these risk factors, development of means to address changing circumstances, and ongoing professional and public education designed to weave firearm injury prevention into the fabric of public health work and everyday life. PMID:17329653

  14. Firearm Injuries: Epidemic Then, Endemic Now

    PubMed Central

    Christoffel, Katherine Kaufer

    2007-01-01

    There has been a transition in US firearm injuries from an epidemic phase (mid-1980s to early 1990s) to an endemic one (since the mid-1990s). Endemic US firearm injuries merit public health attention because they exact an ongoing toll, may give rise to new epidemic outbreaks, and can foster firearm injuries in other parts of the world. The endemic period is a good time for the development of ongoing prevention approaches, including assessment and monitoring of local risk factors over time and application of proven measures to reduce these risk factors, development of means to address changing circumstances, and ongoing professional and public education designed to weave firearm injury prevention into the fabric of public health work and everyday life. PMID:17329653

  15. Characterization of microsatellite markers for Thoropa taophora (Anura, Cycloramphidae), a frog endemic to the Brazilian Atlantic Rain Forest.

    PubMed

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2008-05-01

    Here we characterize nine microsatellite loci for Thoropa taophora collected from a coastal and an island population in southeastern Brazil. The number of alleles per locus ranged from three to 11 for the coastal population and from two to eight for the island population. Observed heterozygosities ranged from 0.308 to 0.778 for the coastal population and from zero to 0.737 for the island population. One locus did not conform to Hardy-Weinberg expectations on the coast, while two were in disequilibrium on the island. These markers are currently being used to examine genetic differentiation and patterns of dispersal in T. taophora. PMID:21585864

  16. Endemic Viruses of Squirrel Monkeys (Saimiri spp.)

    PubMed Central

    Rogers, Donna L; McClure, Gloria B; Ruiz, Julio C; Abee, Christian R; Vanchiere, John A

    2015-01-01

    Nonhuman primates are the experimental animals of choice for the study of many human diseases. As such, it is important to understand that endemic viruses of primates can potentially affect the design, methods, and results of biomedical studies designed to model human disease. Here we review the viruses known to be endemic in squirrel monkeys (Saimiri spp.). The pathogenic potential of these viruses in squirrel monkeys that undergo experimental manipulation remains largely unexplored but may have implications regarding the use of squirrel monkeys in biomedical research. PMID:26141448

  17. How Can We Tell if Frogs Jump Further?

    ERIC Educational Resources Information Center

    Drummond, Gordon B.; Tom, Brian D. M.

    2011-01-01

    How effective is training frogs to jump? This is perhaps the most frequent question in biology that is subjected to statistical analysis: does a treatment make a difference? One can examine whether there is indeed a training effect, by first assuming the opposite. That is, the authors assume that training has no effect on the mean distance jumped.…

  18. 27. 'Frogs' which match up the rail lines on the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. 'Frogs' which match up the rail lines on the tower and the movable span as the bridge closes. North span facing south. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

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

    ERIC Educational Resources Information Center

    Brodie, Carolyn S.

    2005-01-01

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

  20. The "Frog Story" Narratives of Irish-English Bilinguals.

    ERIC Educational Resources Information Center

    Bennett-Kastor, Tina

    2002-01-01

    Bilingual speakers of Irish and English were recorded as they produced narratives based on pictures from the book, "Frog, Where Are You?" The narratives were analyzed according to certain features of global and local structure. Differences within narratives emerged in number of components included, number of planning components explicitly marked…

  1. WEAKLY SYNCHRYRONIZED SUBPOPULATION DYNAMICS IN WISCONSIN FROGS AND TOADS

    EPA Science Inventory

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

  2. Natural disturbance reduces disease risk in endangered rainforest frog populations.

    PubMed

    Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

    2015-01-01

    Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence. PMID:26294048

  3. Natural disturbance reduces disease risk in endangered rainforest frog populations

    PubMed Central

    Roznik, Elizabeth A.; Sapsford, Sarah J.; Pike, David A.; Schwarzkopf, Lin; Alford, Ross A.

    2015-01-01

    Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11–28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence. PMID:26294048

  4. Tetrodotoxin: Occurrence in atelopid frogs of Costa Rica.

    PubMed

    Kim, Y H; Brown, G B; Mosher, F A

    1975-07-11

    The potent neurotoxin tetrodotoxin, which has previously been found in puffer fish of the order Tetraordontiformes, a goby (Gobius criniger), and the California newt (Taricha torosa), has now been identified in the skins of frogs of the genus Atelopus from Costa Rica. PMID:1138374

  5. Occurrence of tetrodotoxin in the frog Atelopus oxyrhynchus.

    PubMed

    Mebs, D; Schmidt, K

    1989-01-01

    Alcohol extracts from the frog Atelopus oxyrhynchus were toxic to mice when injected intraperitoneally. The toxin was purified by gel filtration on a Sephadex G-15 column, and was identified as tetrodotoxin by thin-layer chromatography and GC-MS analysis of the alkali-hydrolyzed and trimethylsilylated derivative giving the same pattern as the C9-base of tetrodotoxin. PMID:2781581

  6. Antimicrobial peptides from frog skin: biodiversity and therapeutic promises.

    PubMed

    Ladram, Ali; Nicolas, Pierre

    2016-01-01

    More than a thousand antimicrobial peptides (AMPs) have been reported in the last decades arising from the skin secretion of amphibian species. Generally, each frog species can express its own repertoire of AMPs (typically, 10-20 peptides) with differing sequences, sizes, and spectrum of action, which implies very rapid divergence, even between closely related species. Frog skin AMPs are highly potent against antibiotic-resistant bacteria, protozoa, yeasts, and fungi by permeating and destroying their plasma membrane and/or inactivating intracellular targets. These peptides have attracted considerable interest as a therapeutic alternative to conventional anti-infective agents. However, efforts to obtain a new generation of drugs using these peptides are still challenging because of high associated R&D costs due to their large size (up to 46 residues) and cytotoxicity. This review deals with the biodiversity of frog skin AMPs and assesses the therapeutic possibilities of temporins, the shortest AMPs found in the frog skin, with 8-17 residues. Such short sequences are easily amenable to optimization of the structure and to solution-phase synthesis that offer reduced costs over solid-phase chemistry. PMID:27100511

  7. Photodynamic inactivation of somatic frog nerve ex vivo

    NASA Astrophysics Data System (ADS)

    Akchurin, Garif G.; Seliverstov, George A.; Akchurin, George G.; Kudryashova, Svetlana Y.

    2004-06-01

    New techniques research mechanisms of photdynamic reactions at somatic frog nerve was approved. Dosimetry PDT with minimum time resolution ~1ms determined by changing the amplitude of compound action potential of somatic frog nerve. Light-induced inactivation of dynamic response of somatic frog nerve on electrical pulsed excitation was study ex vivo. The light-sensitive dyes: methylene blue (Mb), Indocianin green and eryhtrocin-B has been used on photodynamic induced inactivation of the processes generation nerve pulses. Inactivation of consequence action potential of somatic frog nerve using excitation of electical pulsed was achieved by irradiation with He-Ne laser light in a red spectral region (λ=633 nm, power level 2-20 mW), diode laser (λ=805 nm, P<0.1-1 W/cm2) in the case of Indocianin green and YAG:Nd laser (λ=532 nm, P~1mW) for eryhtrocin-B. It was discovered that methylene blue, Indocainine green and erytrocin-B decrease of the amplitude compound action potential of the ensemble neurons. The possible cell death mechanism was connected with damage of the sodium potassium adenosine triphosphatase (K-Na ATP) active transport which decrease of amplitude of compound action potential and decrease lifetime ionic channel of membrane nerve.

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

    NASA Astrophysics Data System (ADS)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

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

  9. AIRBORNE PESTICIDES AND POPULATION DECLINES OF A CALIFORNIA ALPINE FROG

    EPA Science Inventory

    The mountain yellow-legged frog (Rana muscosa) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distribution and temporal variation of ...

  10. Pesticides and Population Declines of California Alpine Frogs

    EPA Science Inventory

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  11. Epidemiology of endemic cretinism in Sikkim, India.

    PubMed

    Sankar, R; Pulger, T; Rai, B; Gomathi, S; Gyatso, T R; Pandav, C S

    1998-01-01

    A survey was conducted in Sikkim to determine the prevalence of endemic cretinism in the state. A household was the basic sampling unit. Villages were selected randomly in the state and from these households were selected randomly using the electoral lists. All members of the households were studied. Total of 17,837 individuals from 3,197 households from 249 villages were studied. There were 8,953 males and 8,884 females. A total of 617 endemic cretins were identified: 316 males and 301 females. The overall prevalence of endemic cretinism was 3.46%: (males 3.53% and females 3.39%). Endemic cretinism was observed in 194 (77.9%) villages studied. Neurological cretinism was the predominant form (98.7%). Deaf-mutism was the most salient neurological feature seen in 472 (76.5%) subjects. Motor system examination revealed proximal spasticity and brisk reflexes, both more marked in the lower limbs. Recording of daily life activities revealed 14.1% of the cretins to be totally dependent and another 23% to be requiring considerable assistance for their daily routine activities. The overall prevalence of goitre found in this survey was 54%. Urinary iodine concentration was estimated from a representative sample of the population; mean 4 micrograms/dl (SD 2.68). This survey shows the existence of severe iodine deficiency in Sikkim. PMID:10771977

  12. ENDEMIC WATERBORNE DISEASE: BENNETT-TYPE

    EPA Science Inventory

    Bennett et al. attempted to estimate national waterborne disease (endemic and epidemic) in 1985 by using both actual data and estimates by CDC experts. These investigators reported that 940,000 cases of waterborne disease and 900 associated deaths could have occurred in the U.S. ...

  13. Fundamental Experiment to Determine Escape Countermeasures for Frogs Falling into Agricultural Canals

    NASA Astrophysics Data System (ADS)

    Watabe, Keiji; Mori, Atsushi; Koizumi, Noriyuki; Takemura, Takeshi

    Frogs often drown in agricultural canals with deep concrete walls, which are installed commonly in paddy fields after land improvement projects in Japan, because they cannot escape after falling into the canal. Therefore, countermeasures that enable frogs to escape from canals are required in some rural areas. An experimental canal with partially sloped walls was used as an escape countermeasure to investigate the preferable angle of slope for the walls, water depth and flow velocity that enables Tokyo Daruma Pond Frogs (Rana porosa porosa), which have no adhesive discs, to easily escape. Walls with slopes of 30-45 degrees allowed 50-60% of frogs to escape from the experimental canals, frogs especially easily climbed the 30 degree sloped walls. When the water depth was 5 cm or flow velocity was greater than 20 cm/s, approximately 80% of the frogs moved downstream and reached the sloped walls because the frogs' toes did not reach the bottom of the canal. However, if the depth was 2 cm and the flow velocity was 5 cm/s, only 4% of the frogs climbed the sloped walls because they could move freely. The frogs appeared to not be good at long-distance swimming and could not remain a long-time under running water. Therefore, walls sloped less than 30 degrees and control of both water depth and flow velocity appears important for enabling frogs to easily escape from canals.

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

    PubMed

    Larson, Don J; Barnes, Brian M

    2016-01-01

    Ice nucleation across the skin of wood frogs (Lithobates sylvaticus) rapidly induces endogenous production of glucose, a cryoprotectant necessary for freeze tolerance. In laboratory studies of freeze tolerance, wood frogs are cooled slowly, often at -0.05°C h(-1), to facilitate high cryoprotectant production and survival. Under natural conditions in Alaska, however, wood frogs accumulate maximal tissue glucose concentrations while cooling at much faster rates, -0.35° to -1.6°C h(-1), and in addition undergo multiple successive freeze-thaw cycles before remaining frozen for the winter. We examined whether simulating these ecologically relevant cooling rates and repeated freeze-thaw events in captive wood frogs results in the high glucose concentrations found in naturally frozen wood frogs. We found that over successive freezing and thawing events, glucose concentrations increased stepwise in all measured tissues. Short thawing periods did not result in a statistically significant decline of glucose concentrations. Wood frogs that experienced three freeze-thaw events had fresh weight glucose concentrations that approached values found in tissues of wood frogs frozen in natural conditions. Laboratory wood frogs survive frozen for 2 mo, while wood frogs frozen under natural conditions survive frozen for up to 7 mo at temperatures below -18°C. We hypothesize that repeated freeze-thaw cycles with rapid cooling and warming rates allow for greater survival in Alaskan wood frogs through enhanced cryoprotectant production. PMID:27327184

  15. Habitat use and spatial structure of a barking frog (Eleutherodactylus augusti) population in southeastern Arizona

    USGS Publications Warehouse

    Goldberg, C.S.; Schwalbe, C.R.

    2004-01-01

    Barking Frogs (Eleutherodactylus augusti) are the northernmost ranging member of the large tropical family Leptodactylidae. We investigated the ecology of this saxicolous species at the northern edge of its range in a canyon in southern Arizona. We captured 54 frogs on discontinuous rock outcrops; eight of nine females and 39 of 45 males were on limestone outcrops. The remaining frogs were closer to limestone outcrops by more than 200 m than would be expected if they were distributed randomly with respect to limestone formations. Seven of 10 frogs radio-tracked had core home ranges (50% fixed kernel) from 94 to 100% on limestone; the other three frogs did not have any part of their home range on limestone outcrops. During five years of mark-recapture efforts, no frogs were found on a different outcrop from the one where they were originally captured; no radio-tracked frogs moved between outcrops during the breeding season. We estimated that four to 20 Barking Frogs occupied each outcrop; these groups probably are connected primarily by juvenile dispersal. As an organism living at the edge of its range, Barking Frogs in Arizona may rely heavily on extensive underground areas such as those found in limestone to protect them from a physiologically challenging environment. To manage for the persistence of Barking Frogs in southern Arizona, we must identify and protect habitat patches and movement pathways among them.

  16. Physiological ecology of aquatic overwintering in ranid frogs.

    PubMed

    Tattersall, Glenn J; Ultsch, Gordon R

    2008-05-01

    In cold-temperate climates, overwintering aquatic ranid frogs must survive prolonged periods of low temperature, often accompanied by low levels of dissolved oxygen. They must do so with the energy stores acquired prior to the onset of winter. Overwintering mortality is a significant factor in their life history, occasionally reaching 100% due to freezing and/or anoxia. Many species of northern ranid frogs overwinter in the tadpole stage, which increases survival during hypoxic episodes relative to adults, as well as allowing for larger sizes at metamorphosis. At temperatures below 5 degrees C, submerged ranid frogs are capable of acquiring adequate oxygen via cutaneous gas exchange over a wide range of ambient oxygen partial pressures (PO(2)), and possess numerous physiological and behavioural mechanisms that allow them to maintain normal rates of oxygen uptake across the skin at a relatively low PO(2). At levels of oxygen near and below the critical PO(2) that allows for aerobic metabolism, frogs must adopt biochemical mechanisms that act to minimise oxygen utilisation and assist in maintaining an aerobic state to survive overwintering. These mechanisms include alterations in mitochondrial metabolism and affinity, changes in membrane permeability, alterations in water balance, and reduction in cellular electrochemical gradients, all of which lead to an overall reduction in whole-animal metabolism. Winter energetic requirements are fueled by the energy stores in liver, muscle, and fat depots, which are likely to be sufficient when the water is cold and well oxygenated. However, under hypoxic conditions fat stores cannot be utilised efficiently and glycogen stores are used up rapidly due to recruitment of anaerobiosis. Since ranid frogs have minimal tolerance to anoxia, it is untenable to suggest that they spend a significant portion of the winter buried in anoxic mud, but instead utilise a suite of behavioural and physiological mechanisms geared to optimal

  17. The Population Decline and Extinction of Darwin’s Frogs

    PubMed Central

    Soto-Azat, Claudio; Valenzuela-Sánchez, Andrés; Collen, Ben; Rowcliffe, J. Marcus; Veloso, Alberto; Cunningham, Andrew A.

    2013-01-01

    Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth-brooding frogs from Chile and Argentina. Here, we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including information on abundance, habitat and threats to extant Darwin’s frog populations. All known archived Rhinoderma specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244 archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings, optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found and our modelling inferred that this species became extinct in 1982 (95% CI, 1980–2000). Rhinoderma darwinii was found in 36 sites. All populations were within native forest and abundance was highest in Chiloé Island, when compared with Coast, Andes and South populations. Estimated population size and density (five populations) averaged 33.2 frogs/population (range, 10.2–56.3) and 14.9 frogs/100 m2 (range, 5.3–74.1), respectively. Our results provide further evidence that R. rufum is extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this species can still be found across a large part of its historical range, remaining populations are small and severely fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered. PMID:23776705

  18. Variation of total mercury concentrations in pig frogs (Rana grylio) across the Florida Everglades, USA.

    PubMed

    Ugarte, Cristina A; Rice, Kenneth G; Donnelly, Maureen A

    2005-06-01

    The Pig Frog (Rana grylio) is an aquatic frog that is an abundant component of the Everglades ecosystem. South Floridians recreationally and commercially hunt pig frogs in marshes throughout Water Conservation Areas (WCA) and Big Cypress National Preserve (BCNP) in South Florida. Most of these areas are under fish consumption advisories because of high levels of methylmercury present in game fish tissues. It is important to understand how mercury is distributed throughout Pig Frog populations because their consumption from certain areas may present a risk to human health. We sampled 88 pig frogs along a north-south transect through the Florida Everglades. There were substantial differences in total mercury (THg) concentrations from leg muscle tissue among sites. Total mercury in frog leg tissue was highest from areas protected from harvest in Everglades National Park (ENP), with a maximum concentration of 2051 ng/g wet mass. The THg levels in R. grylio leg tissue from most harvested areas are below Federal advisory limits. However, many pig frogs collected near Frog City, and one from WCA 3B and 3AN, harvested sites, had THg levels above the USEPA 0.3 mg/kg Fish Tissue Residue Criterion. Spatial patterns in the mercury found among pig frogs were similar to those of other wildlife species from the Everglades. We found frogs to have high THg levels in areas where alligators and mosquito fish also have high THg. THg in ENP frogs had an exponential relationship to SVL, we found no other relationship in frogs from other sites. Our data suggests that pig frogs should not be harvested or consumed from sites that exceed federal limits. PMID:15919527

  19. Effects of polychlorinated biphenyl 126 on green frog (Rana clamitans) and leopard frog (Rana pipiens) hatching success, development, and metamorphosis

    SciTech Connect

    Rosenshield, M.L.; Jofre, M.B.; Karasov, W.H.

    1999-11-01

    Although increasing evidence links plana chlorinated hydrocarbons, such as polychlorinated biphenyls (PCBs), to decreases in survival and reproduction of fish, mammals, and birds near Green Bay, Wisconsin, and the Great Lakes, USA, relatively little is known of their bioaccumulation or of their possible effects in amphibians. The authors exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (Rana pipiens), to PCB 126, a model coplanar PCB compound. Nominal concentrations ranged from 0.005 to 50 {micro}g/L, and exposure lasted through metamorphosis. Tissue concentrations of PCB 126 in tadpoles that did not metamorphose by the end of the experiment ranged from 1.2 to 9,600 ng/g wet mass. No significant mortality of embryos occurred before hatching; however, survival of larvae was significantly reduced at the highest concentration for both species. Few deformities were observed, but the incidence of edema was significantly higher in tadpoles exposed to 50 {micro}g/L. Swimming speed and growth of tadpoles was also significantly reduced in this treatment. The percent of tadpoles that reached metamorphosis was significantly lower in green frogs at the highest concentration, and no leopard frogs survived past day 47 of the experiment in this treatment. At high concentrations, PCB 126 affected both ranid species; however, sublethal effects were not apparent for the parameters the authors measured at concentrations that occur in water in the Green Bay ecosystem.

  20. Endemic cretinism in Thailand: a multidisciplinary survey.

    PubMed

    Rajatanavin, R; Chailurkit, L; Winichakoon, P; Mahachoklertwattana, P; Soranasataporn, S; Wacharasin, R; Chaisongkram, V; Amatyakul, P; Wanarata, L

    1997-10-01

    Endemic cretinism has been classified into neurological and myxedematous types. Profound mental deficiency, deaf-mutism and cerebral diplegia are predominantly found in the former. The latter have been described as less mentally retarded but with severe growth retardation and myxedematous features. The pathogenesis of different clinical types of endemic cretinism is still unclear. Recently, a unifying hypothesis suggested that iodine deficiency, severe enough to cause maternal and fetal hypothyroxinemia, results in neurological defects in all cretins. We conducted the present study in northern Thailand to determine the validity of this hypothesis in another geographical area. The study consisted of a multidisciplinary survey on 112 endemic cretins aged 2-66 years in Nan. They were categorized clinically into three types of endemic cretins, neurological (n = 57), myxedematous (n = 19) and mixed form (n = 36). The subjects were generally short and the majority had severe mental retardation (mean intellectual quotient (I.Q.) 30.8 +/- 8.8), psychomotor defect and profound sensorineural hearing loss. The I.Q. score and proportion of cretins with sensorineural hearing loss and psychomotor defect were similar among the three types of cretins. The most frequent neurological abnormalities were spasticity, hyper-reflexia, the presence of primitive reflexes and gait disturbance. These abnormalities were distributed equally among the three types of endemic cretins. Delayed skeletal maturation and abnormal epiphysis were also present in all types of cretins. However, myxedematous cretins were shorter (P < 0.01), having more myxedematous features (P < 0.05 to P < 0.001) and less sexual maturation (P < 0.05). Thyroid volume was lower in cretins with hypothyroidism (P < 0.01). In conclusion, our findings support the hypothesis that neurological features are present in all types of cretins, and are the consequence of maternal and fetal hypothyroxinemia due to severe iodine

  1. Distribution of Mycobacterium ulcerans in Buruli Ulcer Endemic and Non-Endemic Aquatic Sites in Ghana

    PubMed Central

    Williamson, Heather R.; Benbow, Mark E.; Nguyen, Khoa D.; Beachboard, Dia C.; Kimbirauskas, Ryan K.; McIntosh, Mollie D.; Quaye, Charles; Ampadu, Edwin O.; Boakye, Daniel; Merritt, Richard W.; Small, Pamela L. C.

    2008-01-01

    Mycobacterium ulcerans, the causative agent of Buruli ulcer, is an emerging environmental bacterium in Australia and West Africa. The primary risk factor associated with Buruli ulcer is proximity to slow moving water. Environmental constraints for disease are shown by the absence of infection in arid regions of infected countries. A particularly mysterious aspect of Buruli ulcer is the fact that endemic and non-endemic villages may be only a few kilometers apart within the same watershed. Recent studies suggest that aquatic invertebrate species may serve as reservoirs for M. ulcerans, although transmission pathways remain unknown. Systematic studies of the distribution of M. ulcerans in the environment using standard ecological methods have not been reported. Here we present results from the first study based on random sampling of endemic and non-endemic sites. In this study PCR-based methods, along with biofilm collections, have been used to map the presence of M. ulcerans within 26 aquatic sites in Ghana. Results suggest that M. ulcerans is present in both endemic and non-endemic sites and that variable number tandem repeat (VNTR) profiling can be used to follow chains of transmission from the environment to humans. Our results suggesting that the distribution of M. ulcerans is far broader than the distribution of human disease is characteristic of environmental pathogens. These findings imply that focal demography, along with patterns of human water contact, may play a major role in transmission of Buruli ulcer. PMID:18365034

  2. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

    PubMed Central

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-01-01

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels. PMID:25857262

  3. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to Brown Tree Frogs (Litoria ewingii)

    PubMed Central

    Schadich, Ermin; Cole, Anthony LJ

    2010-01-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 × 107 cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals. PMID:20412685

  4. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

    NASA Astrophysics Data System (ADS)

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-04-01

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

  5. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster.

    PubMed

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-01-01

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations ((134)Cs and (137)Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels. PMID:25857262

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

    PubMed Central

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

    2010-01-01

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

  7. Batrachochytrium dendrobatidis in the live frog trade of Telmatobius (Anura: Ceratophryidae) in the tropical Andes.

    PubMed

    Catenazzi, Alessandro; Vredenburg, Vance T; Lehr, Edgar

    2010-11-01

    Species of frogs in the genus Telmatobius are traded and sold for human consumption in the Andes and in coastal cities of Peru and Bolivia. These frogs are harvested from wild populations. We report high prevalence of infection by the pathogenic fungus Batrachochytrium dendrobatidis in live frogs purchased at the main market in Cusco, Peru, from January 2008 to January 2010. We suggest that the transport of native anurans through the live frog trade could facilitate the spread of this fungus among Andean frogs. The tropical Andes are the most important biodiversity hotspot for amphibians. Because many neotropical taxa are known to be susceptible to chytridiomycosis, the presence of a large reservoir of infection in the frog trade poses a significant threat to amphibian conservation. PMID:21268980

  8. Parathion accumulation in cricket frogs and its effect on American kestrels

    USGS Publications Warehouse

    Fleming, W.J.; de Chacin, H.; Pattee, O.H.; Lamont, T.G.

    1982-01-01

    Adult cricket frogs (Acris crepitans) were held individually for 96 h in static systems containing initial concentrations of either 0, 0.1, 1.0, or 10 ppm parathion in 10 ml water. Mortality of cricket frogs was directly related to the parathion concentration in the water. Frogs from the 1.0- and 10-ppm groups accumulated 0.08 and 4.6 ppm parathion, respectively. One of four American kestrels (Falco sparverius) fed frogs from the 10-ppm group died from organophosphate poisoning less than 3 h after consuming five frogs. Mortality did not occur in kestrels fed frogs from the other treatment groups, which represented more environmentally realistic levels of exposure.

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

    PubMed

    Hardy, Bennett M; Pope, Karen L; Piovia-Scott, Jonah; Brown, Richard N; Foley, Janet E

    2015-01-15

    The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently metamorphosed R. cascadae from 1 of the 11 remnant populations in the Cascades Mountains (CA, USA). Of these, 30 randomly selected frogs were treated with itraconazole and the other 30 frogs served as experimental controls; all were released at the capture site. Bd prevalence was low at the time of treatment and did not differ between treated frogs and controls immediately following treatment. Following release, Bd prevalence gradually increased in controls but not in treated frogs, with noticeable (but still non-significant) differences 3 wk after treatment (27% [4/15] vs. 0% [0/13]) and strong differences 5 wk after treatment (67% [8/12] vs. 13% [1/8]). We did not detect any differences in Bd prevalence and load between experimental controls and untreated wild frogs during this time period. In spring 2013, we recaptured 7 treated frogs but none of the experimental control frogs, suggesting that over-winter survival was higher for treated frogs. The itraconazole treatment did appear to reduce growth rates: treated frogs weighed 22% less than control frogs 3 wk after treatment (0.7 vs. 0.9 g) and were 9% shorter than control frogs 5 wk after treatment (18.4 vs. 20.2 mm). However, for critically small populations, increased survival of the most at-risk life stage could prevent or delay extinction. Our results show that itraconazole treatment can be effective against Bd infection in wild amphibians, and therefore the beneficial effects on survivorship may outweigh the detrimental effects on growth. PMID:25590775

  10. Hydatid Disease Is Endemic in California

    PubMed Central

    Schwabe, Calvin W.; Ruppanner, Roger; Miller, Carl W.; Fontaine, Robert E.; Kagan, Irving G.

    1972-01-01

    Hydatid disease, a parasitic infection of global importance and a condition for which there is no known medical treatment, is established endemically in the Central Valley of California. Only further study will reveal whether or not the infection is now spreading or intensifying or is remaining fairly stable at a relatively low level of endemicity. California physicians should be aware of its presence and the fact that in most sheep-raising areas of the world it constitutes a problem of major medical and public health importance. Although a number of national or regional programs for hydatid disease control have been undertaken, clear progress has been evident only in Iceland, in New Zealand and in the Australian state of Tasmania.2,4,5 PMID:4638400

  11. Endemic Scrub Typhus in South America.

    PubMed

    Weitzel, Thomas; Dittrich, Sabine; López, Javier; Phuklia, Weerawat; Martinez-Valdebenito, Constanza; Velásquez, Katia; Blacksell, Stuart D; Paris, Daniel H; Abarca, Katia

    2016-09-01

    Scrub typhus is a life-threatening zoonosis caused by Orientia tsutsugamushi organisms that are transmitted by the larvae of trombiculid mites. Endemic scrub typhus was originally thought to be confined to the so called "tsutsugamushi triangle" within the Asia-Pacific region. In 2006, however, two individual cases were detected in the Middle East and South America, which suggested that the pathogen was present farther afield. Here, we report three autochthonous cases of scrub typhus caused by O. tsutsugamushi acquired on Chiloé Island in southern Chile, which suggests the existence of an endemic focus in South America. (Funded by the Chilean Comisión Nacional de Investigación Científica y Tecnológica and the Wellcome Trust.). PMID:27602667

  12. Sarcoidosis in tuberculosis-endemic regions: India

    PubMed Central

    2013-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology affecting multiple organs. Earlier reports suggested that sarcoidosis was a disease of the developed world. However, recent reports suggest that the disease is found in the developing countries as well. Clinical, radiological, and histopathological similarities with tuberculosis pose a great challenge in countries endemic for tuberculosis. Mantoux test, high resolution computed tomography, and transbronchial lymph node and lung biopsies are diagnostic modalities, which play an important role in the diagnosis of sarcoid. In this review, we look at the epidemiology of sarcoid in tuberculosis-endemic regions, the sarcoidosis-tuberculosis link, clinical profile, diagnostic modalities, dilemma in the diagnosis, and the treatment of this disease. PMID:23803558

  13. Forecasting dengue vaccine demand in disease endemic and non-endemic countries

    PubMed Central

    Wichmann, Ole; Margolis, Harold S; Mahoney, Richard T

    2010-01-01

    Background A dengue vaccine in large-scale clinical trials could be licensed in several years. We estimated the potential vaccine demand for different introduction strategies in 54 dengue-endemic countries and for travelers from non-endemic countries to enable vaccine producers and public health agencies to better prepare for timely utilization of the vaccine. Results Under our assumptions, 2.4–3.5 billion dengue vaccine doses would be needed in the first five years after introduction with >75% delivered in the public sector. Among 20 potential ‘early-adopter’ countries, an estimated 0.9–1.4 billion doses would be needed for the same introduction approach. For the private sector, covering 10% of children and 30% of adults an estimated 443–664 million doses would be required. In non-endemic countries, travelers could use an estimated 59–89 million vaccine doses, although the present product profile would make it unlikely to be able to administer vaccine in a timely manner. Methods Calculations were based on 2015–2020 population projections for endemic countries in Asia and the Americas with populations >100,000. For dengue-endemic countries we assumed country-wide routine 12–23 month-old vaccination and catch-up vaccination among 2–14 year-old children employing a 2 or 3-dose schedule. Assumptions on expected vaccination coverage were based on country-specific public, private and travelers' sectors immunization performance. Conclusions Our results project an upper-limit estimate of vaccine demand, with actual demand depending on country priorities, cost and product profile. Given the potential for a dengue vaccine, policymakers in endemic and non-endemic countries should consider appropriate implementation strategies in advance of licensure. PMID:20930501

  14. First isolation and identification of Elizabethkingia meningoseptica from cultured tiger frog, Rana tigerina rugulosa.

    PubMed

    Xie, Zhen-Yu; Zhou, Yong-Can; Wang, Shi-Feng; Mei, Bing; Xu, Xian-Dong; Wen, Wan-Yao; Feng, Yong-Qin

    2009-07-01

    Elizabethkingia meningoseptica has been recognised as an occasional but serious opportunistic bacterial pathogen to human beings. Recently, it was frequently isolated from tiger frog, Rana tigerina rugulosa, with cataract disease, which is the most common disease of unknown aetiology of frogs in Hainan, China. The purpose of this study was to identify and characterise the bacterial strains isolated from the recent outbreaks of cataract disease in farmed tiger frog in Hainan, China, and to evaluate their pathogenicity to the frog and their sensitivity to 20 chemotherapeutic agents. The 16S rRNA gene sequences of strains W0701 (1478bp), W0702 (1477bp) and W0703 (1478bp) showed 98.6-98.7% similarity with the sequence of E. meningoseptica type strain (ATCC 13253) and 99.9-100% similarity with that of E. meningoseptica NTU 870424-IL. Six strains (W0701-W0706) were selected to represent 24 isolates retrieved from six moribund frogs. The morphological, physiological and biochemical characteristics of the six representative isolates were consistent with those of E. meningoseptica strains. The organisms were only susceptible to vancomycin and moderately susceptible to cefoperazone among the 20 investigated chemotherapeutic agents. Virulence test with strain W0702 was conducted and pathogenicity (by intramuscular injection) was demonstrated in the tiger frog. In conclusion, 24 isolates obtained from frogs with cataract disease were the E. meningoseptica strains highly pathogenic to tiger frog, and this is the first report of E. meningoseptica as a pathogen for tiger frog. PMID:19327918

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

    SciTech Connect

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

    2005-04-01

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

  16. Old World frog and bird vocalizations contain prominent ultrasonic harmonics

    NASA Astrophysics Data System (ADS)

    Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

    2004-02-01

    Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

  17. The Genome of the Western Clawed Frog Xenopus tropicalis

    SciTech Connect

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

    2009-10-01

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

  18. Monitoring frog communities: An application of machine learning

    SciTech Connect

    Taylor, A.; Watson, G.; Grigg, G.; McCallum, H.

    1996-12-31

    Automatic recognition of animal vocalizations would be a valuable tool for a variety of biological research and environmental monitoring applications. We report the development of a software system which can recognize the vocalizations of 22 species of frogs which occur in an area of northern Australia. This software system will be used in unattended operation to monitor the effect on frog populations of the introduced Cane Toad. The system is based around classification of local peaks in the spectrogram of the audio signal using Quinlan`s machine learning system, C4.5. Unreliable identifications of peaks are aggregated together using a hierarchical structure of segments based on the typical temporal vocalization species` patterns. This produces robust system performance.

  19. Sperm competitiveness in frogs: slow and steady wins the race.

    PubMed

    Dziminski, Martin A; Roberts, J Dale; Beveridge, Maxine; Simmons, Leigh W

    2009-11-22

    When sperm compete to fertilize available ova, selection is expected to favour ejaculate traits that contribute to a male's fertilization success. While there is much evidence to show that selection favours increased numbers of sperm, only a handful of empirical studies have examined how variation in sperm form and function contributes to competitive fertilization success. Here, we examine selection acting on sperm form and function in the externally fertilizing myobatrachid frog, Crinia georgiana. Using in vitro fertilization techniques and controlling for variation in the number of sperm contributed by males in competitive situations, we show that males with a greater proportion of motile sperm, and motile sperm with slower swimming velocities, have an advantage when competing for fertilizations. Sperm morphology and the degree of genetic similarity between putative sires and the female had no influence on competitive fertilization success. These unusual patterns of selection might explain why frog sperm typically exhibit relatively slow swimming speeds and sustained longevity. PMID:19710059

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

    PubMed

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

    2016-01-01

    Tree frogs have become an object of interest in biomimetics due to their ability to cling to wet and slippery surfaces. In this study, we have investigated the adhesion and friction behavior of toe pads of White's tree frog (Litoria caerulea) using atomic force microscopy (AFM) in an aqueous medium. Facilitating special types of AFM probes with radii of ∼400 nm and ∼13 μm, we were able to sense the frictional response without damaging the delicate nanopillar structures of the epithelial cells. While we observed no significant adhesion between both types of probes and toe pads in wet conditions, frictional forces under such conditions were very pronounced and friction coefficients amounted between 0.3 and 1.1 for the sliding friction between probes and the epithelial cell surfaces. PMID:27165465

  1. Spatial Assessment of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) in South Africa Confirms Endemic and Widespread Infection

    PubMed Central

    Tarrant, Jeanne; Cilliers, Dirk; du Preez, Louis H.; Weldon, Ché

    2013-01-01

    Chytridiomycosis has been identified as a major cause of global amphibian declines. Despite widespread evidence of Batrachochytrium dendrobatidis infection in South African frogs, sampling for this disease has not focused on threatened species, or whether this pathogen poses a disease risk to these species. This study assessed the occurrence of Bd-infection in South African Red List species. In addition, all known records of infection from South Africa were used to model the ecological niche of Bd to provide a better understanding of spatial patterns and associated disease risk. Presence and prevalence of Bd was determined through quantitative real-time PCR of 360 skin swab samples from 17 threatened species from 38 sites across the country. Average prevalence was 14.8% for threatened species, with pathogen load varying considerably between species. MaxEnt was used to model the predicted distribution of Bd based on 683 positive records for South Africa. The resultant probability threshold map indicated that Bd is largely restricted to the wet eastern and coastal regions of South Africa. A lack of observed adverse impacts on wild threatened populations supports the endemic pathogen hypothesis for southern Africa. However, all threatened species occur within the limits of the predicted distribution for Bd, exposing them to potential Bd-associated risk factors. Predicting pathogen distribution patterns and potential impact is increasingly important for prioritising research and guiding management decisions. PMID:23894506

  2. Kin-bias, breeding site selection and female fitness in a cannibalistic Neotropical frog.

    PubMed

    Muralidhar, P; de Sá, F P; Haddad, C F B; Zamudio, K R

    2014-02-01

    Resource availability influences sexual selection within populations and determines whether behaviours such as territoriality or resource sharing are adaptive. In Thoropa taophora, a frog endemic to the Atlantic Coastal Rainforest of Brazil, males compete for and defend limited breeding sites while females often share breeding sites with other females; however, sharing breeding sites may involve costs due to cannibalism by conspecific tadpoles. We studied a breeding population of T. taophora to determine (i) whether this species exhibits polygynous mating involving female choice for territorial males and limited breeding resources; (ii) whether limited breeding resources create the potential for male-male cooperation in defence of neighbouring territories; and (iii) whether females sharing breeding sites exhibit kin-biased breeding site choice, possibly driven by fitness losses due to cannibalism among offspring of females sharing sites. We used microsatellites to reconstruct parentage and quantify relatedness at eight breeding sites in our focal population, where these sites are scarce, and in a second population, where sites are abundant. We found that at localities where the appropriate sites for reproduction are spatially limited, the mating system for this species is polygynous, with typically two females sharing a breeding site with a male. We also found that females exhibit negative kin-bias in their choice of breeding sites, potentially to maximize their inclusive fitness by avoiding tadpole cannibalism of highly related kin. Our results indicate that male territorial defence and female site sharing are likely important components of this mating system, and we propose that kinship-dependent avoidance in mating strategies may be more general than previously realized. PMID:24237705

  3. Polyandry, Predation, and the Evolution of Frog Reproductive Modes.

    PubMed

    Zamudio, Kelly R; Bell, Rayna C; Nali, Renato C; Haddad, Célio F B; Prado, Cynthia P A

    2016-09-01

    Frog reproductive modes are complex phenotypes that include egg/clutch characteristics, oviposition site, larval development, and sometimes, parental care. Two evident patterns in the evolution of these traits are the higher diversity of reproductive modes in the tropics and the apparent progression from aquatic to terrestrial reproduction, often attributed to higher fitness resulting from decreased predation on terrestrial eggs and tadpoles. Here, we propose that sexual selection-and not only natural selection due to predation-favors terrestrial breeding by reducing the loss of fitness due to polyandry. To examine this novel selective mechanism, we reconstructed the evolution of reproductive diversity in two frog families (Hylidae and Leptodactylidae) and tested for concerted evolution of egg and tadpole development sites with specific mating behaviors. We found that oviposition and tadpole development sites are evolving independently, do not show the same diversity and/or directionality in terms of terrestriality, and thus may be diversifying due to different selective mechanisms. In both families, terrestrial egg deposition is correlated with amplexus that is hidden from competing males, and in hylids, testes mass was significantly larger and more variable in males with exposed amplexus that are vulnerable to polyandry. Our results indicate that intrasexual selection has been an underappreciated mechanism promoting diversification of frog reproductive modes. PMID:27513910

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

    USGS Publications Warehouse

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

    2013-01-01

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

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

    PubMed

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

    2016-05-01

    Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. PMID:26944494

  6. The glucosidic pathways and glucose production by frog muscle.

    PubMed

    Fournier, P A; Petrof, E O; Guderley, H

    1992-04-25

    Resting muscle is generally perceived as a glucose-utilizing organ; however, we show that resting well-oxygenated frog muscle recovering from strenuous exercise can release significant amounts of glucose. The metabolic pathway responsible for this process does not involve glucose-6-phosphatase because this enzyme is undetectable in frog muscle. The participation of amylo-1,6-glucosidase in the production of glucose is also ruled out since neither marked net phosphorolytic breakdown of glycogen nor considerable cycling between glycogen and glucose 6-phosphate occur. The glucosidic pathways of glycogen breakdown are the likely source of glucose as they are the only metabolic avenues with sufficient capacity to account for the rate at which glucose is released from post-exercised muscle. This rate of glucose production is high enough to be of physiological importance. Our results clearly indicate that to measure lactate glycogenesis in muscle, the simultaneous hydrolysis of muscle glycogen by the glucosidic pathways must be taken into account to prevent marked underestimation of the rate of glycogen synthesis. The glucosidic pathways seem the predominant avenues of glycogen breakdown in post-exercised resting frog muscle and are active enough to account for the rate of glycogen breakdown in resting muscle, suggesting that these rather than the phosphorolytic pathways are the chief routes of glycogen breakdown in resting muscle. PMID:1569076

  7. Relationship between Maximum Leaf Photosynthesis, Nitrogen Content and Specific Leaf Area in Balearic Endemic and Non‐endemic Mediterranean Species

    PubMed Central

    GULÍAS, JAVIER; FLEXAS, JAUME; MUS, MAURICI; CIFRE, JOSEP; LEFI, ELKADRI; MEDRANO, HIPÓLITO

    2003-01-01

    Gas exchange parameters, leaf nitrogen content and specific leaf area (SLA) were measured in situ on 73 C3 and five C4 plant species in Mallorca, west Mediterranean, to test whether species endemic to the Balearic Islands differed from widespread, non‐endemic Mediterranean species and crops in their leaf traits and trait inter‐relationships. Endemic species differed significantly from widespread species and crops in several parameters; in particular, photosynthetic capacity, on an area basis (A), was 20 % less in endemics than in non‐endemics. Similar differences between endemics and non‐endemics were found in parameters such as SLA and leaf nitrogen content per area (Na). Nevertheless, most of the observed differences were found only within the herbaceous deciduous species. These could be due to the fact that most of the non‐endemic species within this group have adapted to ruderal areas, while none of the endemics occupies this kind of habitat. All the species—including the crops—showed a positive, highly significant correlation between photosynthetic capacity on a mass basis (Am), leaf nitrogen content on a mass basis (Nm) and SLA. However, endemic species had a lower Am for any given SLA and Nm. Hypotheses are presented to explain these differences, and their possible role in reducing the distribution of many endemic Balearic species is discussed. PMID:12805082

  8. Snow cover and late fall movement influence wood frog survival during an unusually cold winter.

    PubMed

    O'Connor, Jason H; Rittenhouse, Tracy A G

    2016-07-01

    Understanding how organisms will respond to altered winter conditions is hampered by a paucity of information on the winter ecology for many species. Amphibians are sensitive to environmental temperature and moisture conditions and may be vulnerable to changes in winter climate. We used a combination of radio telemetry and field enclosures to monitor survival of the freeze-tolerant wood frog (Lithobates sylvaticus) during the unusually cold winter of 2013-2014. We experimentally manipulated snow cover to determine the effect of snow removal on winter survival. In addition, we placed a group of untracked frogs at locations used by tracked frogs prior to long-distance late fall movement to investigate whether late fall movement entailed survival consequences. Winter survival was highest (75.3 %) among frogs at post-movement locations that received natural snow cover. The odds of surviving the winter for frogs in the snow removal treatment was only 21.6 % that of frogs in the natural snow treatment. Likewise, paired frogs placed at pre-fall movement locations had only 35.1 % the odds of surviving as tracked frogs at post-fall movement locations. A comparison of a priori models that included microhabitat conditions measured at wood frog overwintering locations revealed that the minimum temperature experienced and the depth of the frog in the substrate explained additional variation in winter survival. Our results suggest that acute exposure to lethal temperature conditions is the most likely cause of mortality during this study, rather than energy exhaustion or desiccation. They also demonstrate the importance of snow cover to the winter survival of wood frogs. PMID:26497126

  9. Natural levels of abnormalities in the trilling frog (neobactrachus centralis) at the Olympic dam mine

    SciTech Connect

    Read, J.L. ); Tyler, M.J. )

    1994-07-01

    Frogs are more susceptible than most vertebrates to environmental contaminants. Unlike amniotes, the frog egg is not protected by a semi-impervious shell, and hence is readily exposed to pollutants. In addition, tadpoles develop in wetlands to which many noxious substances drain from the surrounding landscape. Coupled with this high exposure rate, frogs are also very sensitive to trace elements, some pesticides, heavy metals especially when coupled with exposure to low pH and ionizing radiation. Frogs commonly exhibit discernible deformities following exposure to teratogenic contaminants, and therefore are valuable indicators of the existence of noxious substances in the environment. The abundance and ease of sampling of frogs, along with their sensitivity to environmental contaminants, makes them ideal organisms for environmental monitoring in the Australian arid zone. The study of abnormalities in frogs has become an integral part of the Environmental Management Programme of the Olympic Dam Operations (ODO) copper-uranium-gold-silver mine in northern South Australia. The Trilling Frog (Neobatrachus centralis) is the only frog species which has been recorded at Olympic Dam. It is likely that these frogs, are relatively sedentary, thus enhancing their value as indicator organisms. A pilot survey in 1989 documented frog deformity levels comparable to those found at undisturbed sites in Australia and in other countries. This paper reports on larger study conducted in February and March 1992 when heavy rains provided another opportunity to survey the frog population. The low levels of abnormalities support the conclusion that N. centralis at Olympic Dam does not appear to be accumulating or being influenced by the very low levels of radionuclides present here.

  10. Endemicity and evolutionary value: a study of Chilean endemic vascular plant genera

    PubMed Central

    Scherson, Rosa A; Albornoz, Abraham A; Moreira-Muñoz, Andrés S; Urbina-Casanova, Rafael

    2014-01-01

    This study uses phylogeny-based measures of evolutionary potential (phylogenetic diversity and community structure) to evaluate the evolutionary value of vascular plant genera endemic to Chile. Endemicity is regarded as a very important consideration for conservation purposes. Taxa that are endemic to a single country are valuable conservation targets, as their protection depends upon a single government policy. This is especially relevant in developing countries in which conservation is not always a high resource allocation priority. Phylogeny-based measures of evolutionary potential such as phylogenetic diversity (PD) have been regarded as meaningful measures of the “value” of taxa and ecosystems, as they are able to account for the attributes that could allow taxa to recover from environmental changes. Chile is an area of remarkable endemism, harboring a flora that shows the highest number of endemic genera in South America. We studied PD and community structure of this flora using a previously available supertree at the genus level, to which we added DNA sequences of 53 genera endemic to Chile. Using discrepancy values and a null model approach, we decoupled PD from taxon richness, in order to compare their geographic distribution over a one-degree grid. An interesting pattern was observed in which areas to the southwest appear to harbor more PD than expected by their generic richness than those areas to the north of the country. In addition, some southern areas showed more PD than expected by chance, as calculated with the null model approach. Geological history as documented by the study of ancient floras as well as glacial refuges in the coastal range of southern Chile during the quaternary seem to be consistent with the observed pattern, highlighting the importance of this area for conservation purposes. PMID:24683462

  11. Endemicity and evolutionary value: a study of Chilean endemic vascular plant genera.

    PubMed

    Scherson, Rosa A; Albornoz, Abraham A; Moreira-Muñoz, Andrés S; Urbina-Casanova, Rafael

    2014-03-01

    This study uses phylogeny-based measures of evolutionary potential (phylogenetic diversity and community structure) to evaluate the evolutionary value of vascular plant genera endemic to Chile. Endemicity is regarded as a very important consideration for conservation purposes. Taxa that are endemic to a single country are valuable conservation targets, as their protection depends upon a single government policy. This is especially relevant in developing countries in which conservation is not always a high resource allocation priority. Phylogeny-based measures of evolutionary potential such as phylogenetic diversity (PD) have been regarded as meaningful measures of the "value" of taxa and ecosystems, as they are able to account for the attributes that could allow taxa to recover from environmental changes. Chile is an area of remarkable endemism, harboring a flora that shows the highest number of endemic genera in South America. We studied PD and community structure of this flora using a previously available supertree at the genus level, to which we added DNA sequences of 53 genera endemic to Chile. Using discrepancy values and a null model approach, we decoupled PD from taxon richness, in order to compare their geographic distribution over a one-degree grid. An interesting pattern was observed in which areas to the southwest appear to harbor more PD than expected by their generic richness than those areas to the north of the country. In addition, some southern areas showed more PD than expected by chance, as calculated with the null model approach. Geological history as documented by the study of ancient floras as well as glacial refuges in the coastal range of southern Chile during the quaternary seem to be consistent with the observed pattern, highlighting the importance of this area for conservation purposes. PMID:24683462

  12. Condition-dependent reproductive effort in frogs infected by a widespread pathogen.

    PubMed

    Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

    2015-07-01

    To minimize the negative effects of an infection on fitness, hosts can respond adaptively by altering their reproductive effort or by adjusting their timing of reproduction. We studied effects of the pathogenic fungus Batrachochytrium dendrobatidis on the probability of calling in a stream-breeding rainforest frog (Litoria rheocola). In uninfected frogs, calling probability was relatively constant across seasons and body conditions, but in infected frogs, calling probability differed among seasons (lowest in winter, highest in summer) and was strongly and positively related to body condition. Infected frogs in poor condition were up to 40% less likely to call than uninfected frogs, whereas infected frogs in good condition were up to 30% more likely to call than uninfected frogs. Our results suggest that frogs employed a pre-existing, plastic, life-history strategy in response to infection, which may have complex evolutionary implications. If infected males in good condition reproduce at rates equal to or greater than those of uninfected males, selection on factors affecting disease susceptibility may be minimal. However, because reproductive effort in infected males is positively related to body condition, there may be selection on mechanisms that limit the negative effects of infections on hosts. PMID:26063847

  13. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs.

    PubMed

    Bernal, Ximena E; Pinto, C Miguel

    2016-04-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes. PMID:26977404

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

    EPA Science Inventory

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

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

    USGS Publications Warehouse

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

    2013-01-01

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

  16. Cues used in host-seeking behavior by frog-biting midges (Corethrella spp. Coquillet).

    PubMed

    Bernal, Ximena E; de Silva, Priyanka

    2015-06-01

    We investigated the role of carbon dioxide and host temperature in host attraction in frog-biting midges (Corethrella spp). In these midges, females are known to use frog calls to localize their host, but the role of other host-emitted cues has yet not been investigated. We hypothesized that carbon dioxide acts as a supplemental cue to frog calls. To test this hypothesis, we determined the responses of the midges to carbon dioxide, frog calls, and both cues. A significantly lower number of midges are attracted to carbon dioxide and silent traps than to traps broadcasting frog calls. Adding carbon dioxide to the calls does not increase the attractiveness to the midges. Instead, carbon dioxide can have deterrent effects on frog-biting midges. Temperature of calling frogs is not a cue potentially available to the midges. Contrary to our hypothesis, there was no supplemental effect of carbon dioxide when presented in conjunction to calls. Midge host-seeking behavior strongly depends on the mating calls emitted by their anuran host. Overall, non-acoustic cues such as host body temperature and carbon dioxide are not important in long-distance host location by frog-biting midges. PMID:26047192

  17. Condition-dependent reproductive effort in frogs infected by a widespread pathogen

    PubMed Central

    Roznik, Elizabeth A.; Sapsford, Sarah J.; Pike, David A.; Schwarzkopf, Lin; Alford, Ross A.

    2015-01-01

    To minimize the negative effects of an infection on fitness, hosts can respond adaptively by altering their reproductive effort or by adjusting their timing of reproduction. We studied effects of the pathogenic fungus Batrachochytrium dendrobatidis on the probability of calling in a stream-breeding rainforest frog (Litoria rheocola). In uninfected frogs, calling probability was relatively constant across seasons and body conditions, but in infected frogs, calling probability differed among seasons (lowest in winter, highest in summer) and was strongly and positively related to body condition. Infected frogs in poor condition were up to 40% less likely to call than uninfected frogs, whereas infected frogs in good condition were up to 30% more likely to call than uninfected frogs. Our results suggest that frogs employed a pre-existing, plastic, life-history strategy in response to infection, which may have complex evolutionary implications. If infected males in good condition reproduce at rates equal to or greater than those of uninfected males, selection on factors affecting disease susceptibility may be minimal. However, because reproductive effort in infected males is positively related to body condition, there may be selection on mechanisms that limit the negative effects of infections on hosts. PMID:26063847

  18. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

    PubMed Central

    Bernal, Ximena E.; Pinto, C. Miguel

    2016-01-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes. PMID:26977404

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

  20. The toxicity of Poison Dart Frog alkaloids against the Fire Ant (Solenopsis invicta)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hundreds of alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These alkaloids are derived from arthropod prey of the frogs, and are generally are believed to deter vertebrate predators. We developed a method to put ind...

  1. Microbial endemism: does phosphorus limitation enhance speciation?

    PubMed

    Souza, Valeria; Eguiarte, Luis E; Siefert, Janet; Elser, James J

    2008-07-01

    There is increasing evidence for the existence of unique ecosystems that are dominated by locally adapted microbiota which harbour distinct lineages and biological capabilities, much like the macrobiota of Darwin's Galapagos Islands. As a primary example of such a system, we highlight key discoveries from the Cuatro Ciénegas basin in Mexico. We argue that high microbial endemism requires a combination of geographical isolation, long-term continuity and mechanisms for reducing the intensity of horizontal gene transfer (HGT). We also propose that strong phosphorus limitation has an important role in microbial diversification by reducing the intensity of HGT. PMID:18521074

  2. Endemic mycoses in AIDS: a clinical review.

    PubMed Central

    Wheat, J

    1995-01-01

    Histoplasmosis and coccidioidomycosis are serious opportunistic infections in patients with AIDS who reside in areas of endemicity of the United States and Central and South America. Blastomycosis, although less common, also must be recognized as an opportunistic infection in patients with AIDS. Prompt diagnosis requires knowledge of the clinical syndromes and diagnostic tests as well as a high index of suspicion. Histoplasmosis and blastomycosis respond well to antifungal treatment, but relapse is common without chronic suppressive therapy. Improvements in treatment are needed in coccidioidomycosis. Research is needed to identify preventive strategies for patients at risk. These strategies may include use of prophylactic antifungal therapy or vaccination. PMID:7704892

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

    PubMed Central

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

    2016-01-01

    Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic ‘Polypedates’ jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features. PMID:26790105

  4. Parasites of the mink frog (rana septentrionalis) from minnesota, U.S.A.

    USGS Publications Warehouse

    Schotthoefer, A.M.; Bolek, M.G.; Cole, R.A.; Beasley, V.R.

    2009-01-01

    Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

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

    SciTech Connect

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

    2005-01-01

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

  6. Absence of tetrodotoxins in a captive-raised riparian frog, Atelopus varius.

    PubMed

    Daly, J W; Padgett, W L; Saunders, R L; Cover, J F

    1997-05-01

    Bufonid frogs of the genus Atelopus contain two classes of skin toxins, namely the steroidal bufadienolides and the water-soluble tetrodotoxins. Frogs of the Panamanian species Atelopus varius have now been raised in captivity and levels in skin extracts of bufadienolides and of tetrodotoxin-like compounds assessed, using inhibition of [3H]ouabain binding and inhibition of [3H]saxitoxin binding, respectively. Levels of ouabain equivalents, corresponding to bufadienolides, were comparable to those found in wild-caught frogs from the same population in Panama, while tetrodotoxin-like activity was undetectable. The results strongly implicate environmental factors, perhaps symbiotic microorganisms, in the genesis of tetrodotoxins in the skin of frogs of the genus Atelopus, while indicating that the frog itself produces the skin bufadienolides. PMID:9203295

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

    PubMed

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

    2016-01-01

    Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features. PMID:26790105

  8. Evolutionary relationships of endemic/epidemic and sylvatic dengue viruses.

    PubMed

    Wang, E; Ni, H; Xu, R; Barrett, A D; Watowich, S J; Gubler, D J; Weaver, S C

    2000-04-01

    Endemic/epidemic dengue viruses (DEN) that are transmitted among humans by the mosquito vectors Aedes aegypti and Aedes albopictus are hypothesized to have evolved from sylvatic DEN strains that are transmitted among nonhuman primates in West Africa and Malaysia by other Aedes mosquitoes. We tested this hypothesis with phylogenetic studies using envelope protein gene sequences of both endemic/epidemic and sylvatic strains. The basal position of sylvatic lineages of DEN-1, -2, and -4 suggested that the endemic/epidemic lineages of these three DEN serotypes evolved independently from sylvatic progenitors. Time estimates for evolution of the endemic/epidemic forms ranged from 100 to 1,500 years ago, and the evolution of endemic/epidemic forms represents relatively recent events in the history of DEN evolution. Analysis of envelope protein amino acid changes predicted to have accompanied endemic/epidemic emergence suggested a role for domain III in adaptation to new mosquito and/or human hosts. PMID:10708439

  9. Optimising Regionalisation Techniques: Identifying Centres of Endemism in the Extraordinarily Endemic-Rich Cape Floristic Region

    PubMed Central

    Bradshaw, Peter L.; Colville, Jonathan F.; Linder, H. Peter

    2015-01-01

    We used a very large dataset (>40% of all species) from the endemic-rich Cape Floristic Region (CFR) to explore the impact of different weighting techniques, coefficients to calculate similarity among the cells, and clustering approaches on biogeographical regionalisation. The results were used to revise the biogeographical subdivision of the CFR. We show that weighted data (down-weighting widespread species), similarity calculated using Kulczinsky’s second measure, and clustering using UPGMA resulted in the optimal classification. This maximized the number of endemic species, the number of centres recognized, and operational geographic units assigned to centres of endemism (CoEs). We developed a dendrogram branch order cut-off (BOC) method to locate the optimal cut-off points on the dendrogram to define candidate clusters. Kulczinsky’s second measure dendrograms were combined using consensus, identifying areas of conflict which could be due to biotic element overlap or transitional areas. Post-clustering GIS manipulation substantially enhanced the endemic composition and geographic size of candidate CoEs. Although there was broad spatial congruence with previous phytogeographic studies, our techniques allowed for the recovery of additional phytogeographic detail not previously described for the CFR. PMID:26147438

  10. Acoustic Monitoring System for Frog Population Estimation Using In-Situ Progressive Learning

    NASA Astrophysics Data System (ADS)

    Aboudan, Adam

    Frog populations are considered excellent bio-indicators and hence the ability to monitor changes in their populations can be very useful for ecological research and environmental monitoring. This thesis presents a new population estimation approach based on the recognition of individual frogs of the same species, namely the Pseudacris Regilla (Pacific Chorus Frog), which does not rely on the availability of prior training data. An in-situ progressive learning algorithm is developed to determine whether an incoming call belongs to a previously detected individual frog or a newly encountered individual frog. A temporal call overlap detector is also presented as a pre-processing tool to eliminate overlapping calls. This is done to prevent the degrading of the learning process. The approach uses Mel-frequency cepstral coefficients (MFCCs) and multivariate Gaussian models to achieve individual frog recognition. In the first part of this thesis, the MFCC as well as the related linear predictive cepstral coefficients (LPCC) acoustic feature extraction processes are reviewed. The Gaussian mixture models (GMM) are also reviewed as an extension to the classical Gaussian modeling used in the proposed approach. In the second part of this thesis, the proposed frog population estimation system is presented and discussed in detail. The proposed system involves several different components including call segmentation, feature extraction, overlap detection, and the in-situ progressive learning process. In the third part of the thesis, data description and system performance results are provided. The process of synthetically generating test sequences of real frog calls, which are applied to the proposed system for performance analysis, is described. Also, the results of the system performance are presented which show that the system is successful in distinguishing individual frogs, hence capable of providing reasonable estimates of the frog population. The system can readily be

  11. Endemic goitre, nutrition, and landholding in Bangladesh.

    PubMed

    Stone, T

    1984-03-01

    Endemic goitre in adult females, cretinism, and anthropometry in children were examined in a goitrous area of Bangladesh. An area survey showed total goitre varying from 62.0 to 93.0%, visible goitre from 9.0 to 54.8% between areas. A village study examining thyroid size in 538 adult females and anthropometry in 116 children showed goitre prevalences varying significantly (p less than 0.001) but unpredictably with household landholding size; underweight and wasting varied inversely and significantly (p less than 0.01 and 0.05 respectively) with the same socioeconomic indicator. By household, there was no relationship between anthropometry in children and thyroid enlargement in the mother. Hormone analyses showed depressed serum T4, but no raised TSH. Only one deaf-mute cretin was found in the area. It is speculated that variation in goitre prevalence in this moderately severe endemic primarily reflects qualitative and quantitative changes in diet, as a function of the socioeconomic status of the household. PMID:6698705

  12. Endemic predators, invasive prey and native diversity.

    PubMed

    Wanger, Thomas C; Wielgoss, Arno C; Motzke, Iris; Clough, Yann; Brook, Barry W; Sodhi, Navjot S; Tscharntke, Teja

    2011-03-01

    Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity. PMID:20826488

  13. Endemic predators, invasive prey and native diversity

    PubMed Central

    Wanger, Thomas C.; Wielgoss, Arno C.; Motzke, Iris; Clough, Yann; Brook, Barry W.; Sodhi, Navjot S.; Tscharntke, Teja

    2011-01-01

    Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity. PMID:20826488

  14. Hydroclimatological Controls of Endemic and Non-endemic Cholera of the 20th Century

    NASA Astrophysics Data System (ADS)

    Jutla, A. S.; Whitcombe, E.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat for the developing countries. Since the causative agent, Vibrio cholerae, is autochthonous to aquatic environment, it is not possible to eradicate the agent of the disease. Hydroclimatology based prediction and prevention strategies can be implemented in disease susceptible regions for reducing incidence rates. However, the precise role of hydrological and climatological processes, which will further aid in development of suitable prediction models, in creating spatial and temporal environmental conditions favorable for disease outbreak has not been adequately quantified. Here, we show distinction between seasonality and occurrence of cholera in epidemic and non-endemic regions. Using historical cholera mortality data, from the late 1800s for 27 locations in the Indian subcontinent, we show that non-endemic regions are generally located close to regional river systems but away from the coasts and are characterized by single sporadic outbreak in a given year. Increase in air temperature during the low river flow season increases evaporation, leading to an optimal salinity and pH required for bacterial growth. Thereafter, monsoonal rainfall, leads to interactions of contaminated river waters via human activity resulting in cholera epidemics. Endemic regions are located close to coasts where cholera outbreak occurs twice (spring and fall) in a year. Spring outbreak is generally associated with intrusion of bacterial seawater to inland whereas the fall peak is correlated with widespread flooding and cross-contamination of water resources via increased precipitation. This may be one of the first studies to hydroclimatologically quantitatively the seasonality of cholera in both endemic and non-endemic regions. Our results prompt the need of region and cause-specific prediction models for cholera, employing appropriate environmental determinants.

  15. Endemism patterns in the Italian leaf beetle fauna (Coleoptera, Chrysomelidae)

    PubMed Central

    Biondi, Maurizio; Urbani, Fabrizia; D’Alessandro, Paola

    2013-01-01

    Abstract In this contribution the results of a zoogeographical analysis, carried out on the 123 endemic leaf beetle species (Coleoptera: Chrysomelidae) occurring in Italy and its immediately adjacent regions, are reported. To assess the level of faunistic similarity among the different geographic regions studied, a cluster analysis was performed, based on the endemic component. This was done by calculating the Baroni Urbani & Buser’s similarity index (BUB). Finally, a parsimony analysis of endemicity (PAE) was used to identify the most important areas of endemism in Italy. PMID:24163584

  16. Comparison of immune responses to a killed bivalent whole cell oral cholera vaccine between endemic and less endemic settings.

    PubMed

    Desai, Sachin N; Akalu, Zenebe; Teferi, Mekonnen; Manna, Byomkesh; Teshome, Samuel; Park, Ju Yeon; Yang, Jae Seung; Kim, Deok Ryun; Kanungo, Suman; Digilio, Laura

    2016-02-01

    Studies on safety, immunogenicity and efficacy of the killed, bivalent whole cell oral cholera vaccine (Shanchol) have been conducted in historically endemic settings of Asia. Recent cholera vaccination campaigns in Haiti and Guinea have also demonstrated favourable immunogenicity and effectiveness in nonendemic outbreak settings. We performed a secondary analysis, comparing immune responses of Shanchol from two randomised controlled trials performed in an endemic and a less endemic area (Addis Ababa) during a nonoutbreak setting. While Shanchol may offer some degree of immediate protection in primed populations living in cholera endemic areas, as well as being highly immunogenic in less endemic settings, understanding the characteristics of immune responses in each of these areas is vital in determining ideal dosing strategies that offer the greatest public health impact to populations from areas with varying degrees of cholera endemicity. PMID:26681205

  17. Assessment of water pollution in the Brazilian Pampa biome by means of stress biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii (Anura: Hylidae)

    PubMed Central

    Santos, TG; Melo, R; Costa-Silva, DG; Nunes, MEM; Rodrigues, NR

    2015-01-01

    The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Studies with a focus on the assessment of impacts caused by human activities in this biome are scarce. In the present study, we measured stress-related biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii, an endemic species to the Pampa biome, and tested its suitability as a bioindicator for the assessment of potential aquatic contamination in selected ponds (S1 and S2) nearby agricultural areas in comparison to a reference site. A significant decrease in acetylcholinesterase activity was observed in S2 when compared to S1 and reference. The levels of total-hydroperoxides were increased in S2 site. In parallel, increased activity of the antioxidant enzymes catalase, superoxide dismutase and glutathione S-transferase were observed in S2 when compared to S1 and reference. Further studies are necessary in order to correlate the changes observed here with different chemical stressors in water, as well as to elucidate mechanisms of toxicity induced by pesticides in amphibian species endemic to the Pampa biome. Nevertheless, our study validates Phyllomedusa iheringii as a valuable bioindicator in environmental studies. PMID:26056614

  18. Assessment of water pollution in the Brazilian Pampa biome by means of stress biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii (Anura: Hylidae).

    PubMed

    Santos, T G; Melo, R; Costa-Silva, D G; Nunes, Mem; Rodrigues, N R; Franco, J L

    2015-01-01

    The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Studies with a focus on the assessment of impacts caused by human activities in this biome are scarce. In the present study, we measured stress-related biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii, an endemic species to the Pampa biome, and tested its suitability as a bioindicator for the assessment of potential aquatic contamination in selected ponds (S1 and S2) nearby agricultural areas in comparison to a reference site. A significant decrease in acetylcholinesterase activity was observed in S2 when compared to S1 and reference. The levels of total-hydroperoxides were increased in S2 site. In parallel, increased activity of the antioxidant enzymes catalase, superoxide dismutase and glutathione S-transferase were observed in S2 when compared to S1 and reference. Further studies are necessary in order to correlate the changes observed here with different chemical stressors in water, as well as to elucidate mechanisms of toxicity induced by pesticides in amphibian species endemic to the Pampa biome. Nevertheless, our study validates Phyllomedusa iheringii as a valuable bioindicator in environmental studies. PMID:26056614

  19. Reproductive maturation of the tropical clawed frog: Xenopus tropicalis.

    PubMed

    Olmstead, Allen W; Korte, Joseph J; Woodis, Kacie K; Bennett, Blake A; Ostazeski, Shannon; Degitz, Sigmund J

    2009-01-15

    The tropical clawed frog, Xenopus tropicalis, is a relatively new model species being used in developmental biology and amphibian toxicology studies. In order to increase our understanding of reproductive maturation and the role of steroid hormones in X. tropicalis, we collected baseline reproductive data in this species from metamorphosis to adulthood. One cohort of frogs was maintained for 42 weeks post-metamorphosis (PM) with endpoints representative of important reproductive parameters collected at 1- or 2-week intervals. These endpoints were then correlated to titers of either estradiol or testosterone. Male frogs exhibited nuptial pads, starting at 8 weeks (PM) when measureable concentrations of circulating testosterone (5.3 ng/mL plasma) first appeared. Testosterone concentrations remained above this level at all later time points, but were highly variable among individuals. Testes sizes in males reached their peak at 22 weeks PM (21 mg) with sperm counts peaking at the same time (25 million sperm/male). In females, estradiol becomes elevated in the blood at 16 weeks PM (1.5 ng/mL plasma) which corresponds with the presences of vitellogenin (4.4 mg/mL plasma), vitellogenic oocytes in the ovary, ovarian growth, and oviduct growth. Vitellogenic oocytes increased in number up to 15,000 per female at 30 weeks PM and accounted for 75% of the total number of oocytes present in the ovary. The ovary and oviducts continued to grow in mass until 30 weeks PM at which point they had reached sizes of 3.6g and 0.8 g, respectively. These data indicate that male and female X. tropicalis reach reproductive maturation at 22 and 30 weeks PM, respectively. Results from this study are valuable for the design of amphibian toxicology assays and increase our understanding of the reproductive biology of this relatively new model species. PMID:19027014

  20. Delimiting the distribution range of Indirana leithii (Boulenger, 1888) (Anura: Ranixalidae), an endemic threatened anuran of the Western Ghats, based on molecular and morphological analysis.

    PubMed

    Modak, Nikhil; Padhye, Anand; Dahanukar, Neelesh

    2014-01-01

    Indirana leithii (Boulenger, 1888) (Anura: Ranixalidae) is a frog species endemic to the Western Ghats and is categorized as Vulnerable according to IUCN red list. This species is currently considered to be widespread over the entire Western Ghats. Our study based on molecular data (using DNA sequence fragments of the mitochondrial 12S rRNA and 16S rRNA genes and the nuclear rhodopsin gene), morphological analysis of topotypic material as well as material collected from a wide range within the northern Western Ghats, suggests that the species has instead a restricted range in the state of Maharashtra. Specimens identified as I. leithii from the southern Western Ghats as well as from outside the Western Ghats probably belong to hitherto undescribed species. To facilitate future studies in understanding the nature of this species complex and provide better means for identification and delimitation of species we provide molecular, morphological and osteological characters of I. leithii from topotyic material. PMID:24870665

  1. Craniofacial malformation among endemic cretins in Ecuador.

    PubMed

    Israel, H; Johnson, G F; Fierro-Benitez, R

    1983-01-01

    Nearly 6% of the inhabitants of two villages in Ecuador are deaf-mute and mentally retarded cretins. These communities are situated in the Andean highlands where environmental and dietary stores of iodine are extremely scarce. Endemic goiter and cretinism are widespread, and 10% of the cretins are additionally burdened with dwarfism and facial dysmorphia. Those with obvious involvement of the skeletal system were selected in order to study the extent of craniofacial malformation. Their appearance is characterized by midface hypoplasia, a broad nose with a depressed bridge, and a conspicuous circumoral prominence. Radiographic evaluation demonstrates a vertical displacement of the cranial base with an associated upward tilt of the midface. The flattened frontal bone, reduced frontal sinus pneumatization, and diminutive nasal bones collectively create a backward sloping face. The defect in the craniofacial skeleton of these Ecuadorian cretins is characteristic, and it readily sets them apart from the dysmorphism of those cretins with myxedema. PMID:6874895

  2. Endemic cattle diseases: comparative epidemiology and governance

    PubMed Central

    Carslake, David; Grant, Wyn; Green, Laura E.; Cave, Jonathan; Greaves, Justin; Keeling, Matt; McEldowney, John; Weldegebriel, Habtu; Medley, Graham F.

    2011-01-01

    Cattle are infected by a community of endemic pathogens with different epidemiological properties that invoke different managerial and governmental responses. We present characteristics of pathogens that influence their ability to persist in the UK, and describe a qualitative framework of factors that influence the political response to a livestock disease. We develop simple transmission models for three pathogens (bovine viral diarrhoea virus, bovine herpesvirus and Mycobacterium avium spp. paratuberculosis) using observed cattle movements, and compare the outcomes to an extensive dataset. The results demonstrate that the epidemiology of the three pathogens is determined by different aspects of within- and between-farm processes, which has economic, legal and political implications for control. We consider how these pathogens, and Mycobacterium bovis (the agent of bovine tuberculosis), may be classified by the process by which they persist and by their political profile. We further consider the dynamic interaction of these classifications with pathogen prevalence and with the action taken by the government. PMID:21624918

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

    PubMed

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

    2016-01-01

    We have succeeded in creating see-through frogs from natural color mutants of the Japanese brown frog Rana japonica, which usually possesses an ochre or brown back; this coloration enables the organs, blood vessels, and eggs to be observed through the skin without performing dissection. We crossed two kinds of recessive color mutant (black-eyed and gray-eyed) frogs through artificial insemination, and F2 offspring produced frogs whose skin is translucent throughout the life cycle. Three kinds of dermal chromatophores-xanthophores, iridophores, and melanophores-are observed in a layered arrangement in the skin of wild-type frogs, but few chromatophores were present in the skin of the see-through frogs. The translucent skin enables observation of organ growth and cancer formation and progression in the animal, which can be monitored over its entire life without the need for dissection. See-through frogs thus provide a useful animal model for environmental, medical, and biological research. PMID:27080918

  4. Poison frogs rely on experience to find the way home in the rainforest.

    PubMed

    Pašukonis, Andrius; Warrington, Ian; Ringler, Max; Hödl, Walter

    2014-11-01

    Among vertebrates, comparable spatial learning abilities have been found in birds, mammals, turtles and fishes, but virtually nothing is known about such abilities in amphibians. Overall, amphibians are the most sedentary vertebrates, but poison frogs (Dendrobatidae) routinely shuttle tadpoles from terrestrial territories to dispersed aquatic deposition sites. We hypothesize that dendrobatid frogs rely on learning for flexible navigation. We tested the role of experience with the local cues for poison frog way-finding by (i) experimentally displacing territorial males of Allobates femoralis over several hundred metres, (ii) using a harmonic direction finder with miniature transponders to track these small frogs, and (iii) using a natural river barrier to separate the translocated frogs from any familiar landmarks. We found that homeward orientation was disrupted by the translocation to the unfamiliar area but frogs translocated over similar distances in their local area showed significant homeward orientation and returned to their territories via a direct path. We suggest that poison frogs rely on spatial learning for way-finding in their local area. PMID:25411379

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

  6. Prevalence of malformed frogs in Kaoping and Tungkang river basins of southern Taiwan.

    PubMed

    Huang, Da-Ji; Chiu, Yuh-Wen; Chen, Chien-Min; Huang, Kai-Hsiang; Wang, Shu-Yin

    2010-05-01

    In this study we found many amphibians with bizarre appearances, known as malformations in Pingtung County southern Taiwan. For this investigation we collected frogs inhabiting the Kaoping and Tungkang river watersheds between February 2006 and June 2007. Among the total number of 10,909 normal frogs (i.e., anurans) collected during the investigation period, the Indian rice frogs (Rana limnocharis) account for the greatest number next is the Chinese bullfrog (Rana rugulosa). Of all the 244 captured malformed frogs, the Indian rice frog account for the greatest proportion. These malformed frogs have their main distribution in upstream areas of these two rivers. Our result indicates that the appearance rate of malformed frogs is 1.8% in the upstream reaches of the Kaoping River and 2.6%, and 0.8%, respectively in the upstream and midstream reaches of the Tungkang river. The most-commonly-found malformation is the lack of palms, followed by the lack of appendages, exostosis, and a malformed appendicular. It is, therefore, reasonable to speculate that the causes for the malformation may be related to the increased organic pollutants and agricultural chemicals used in the upstream reaches of these two rivers. PMID:21047008

  7. Leopard frog PCB levels and evaluation of EROD as a biomarker in Green Bay ecosystem

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.P.

    1995-12-31

    The induction of mixed function oxidases has been shown to be a promising biomarker in many taxa of wildlife, though not yet tested for amphibians. The three hypotheses tested in this study were (1) activities of hepatic EROD of leopard frog (Rana pipiens) are induced following exposure to planar chlorinated PCBs, (2) tissue PCB residue levels of leopard frogs are positively correlated with their wetland sediment PCB levels, and (3) EROD activities are positively correlated with tissue PCB concentrations and sediment PCB. In the laboratory, EROD was increased 2--3 times seven days after i.p. injection with PCB 126 at doses {ge} 2.3 ppm (wet mass basis). Leopard frogs from seven sites along the Lower Fox River and Green Bay in 1994--1995 were assayed for hepatic EROD activities and total PCB levels in carcasses. Tissue PCB levels ranged from 3 to 152 ppb (including coplanar congeners) and were highest from sites with higher sediment PCB. EROD activity in frogs collected in August--September was not significantly correlated with frog body mass and was similar among sites with one exception. There was no significant correlation between EROD activity and tissue PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB levels compared with what was required for induction in the laboratory. The authors conclude that EROD activity is not a sensitive biomarker of PCB exposure in leopard frogs in this ecosystem.

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

    PubMed Central

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

    2016-01-01

    We have succeeded in creating see-through frogs from natural color mutants of the Japanese brown frog Rana japonica, which usually possesses an ochre or brown back; this coloration enables the organs, blood vessels, and eggs to be observed through the skin without performing dissection. We crossed two kinds of recessive color mutant (black-eyed and gray-eyed) frogs through artificial insemination, and F2 offspring produced frogs whose skin is translucent throughout the life cycle. Three kinds of dermal chromatophores—xanthophores, iridophores, and melanophores—are observed in a layered arrangement in the skin of wild-type frogs, but few chromatophores were present in the skin of the see-through frogs. The translucent skin enables observation of organ growth and cancer formation and progression in the animal, which can be monitored over its entire life without the need for dissection. See-through frogs thus provide a useful animal model for environmental, medical, and biological research. PMID:27080918

  9. Chasing maximal performance: a cautionary tale from the celebrated jumping frogs of Calaveras County.

    PubMed

    Astley, H C; Abbott, E M; Azizi, E; Marsh, R L; Roberts, T J

    2013-11-01

    Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: 'rental' frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, 'professional' teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates. PMID:24133149

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

    PubMed

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

    2014-01-01

    Four Japanese forest green tree frogs (Rhacophorus arboreus) were presented with emaciation, abdominal distention and ulcerative and nodular cutaneous lesions affecting the brisket, limbs, digits and ventral abdomen. Another three frogs had been found dead in the same tank 1 year previously. Necropsy examination of these seven frogs revealed splenomegaly and hepatomegaly, with multiple tan-yellow nodular foci present in the liver, spleen, heart, lungs, ovaries and kidneys. Microscopically, five frogs had necrosis and surrounding granulomatous inflammation in the liver, spleen, kidneys, lungs, intestine and ovaries, with numerous acid-fast bacilli in the areas of necrosis. Two frogs had granulomatous lesions in the lungs, liver, spleen, heart, coelomic membrane, stomach and intestinal wall. These lesions had no or minimal necrosis and few acid-fast bacilli. Mycobacterium spp. was cultured from three frogs and identified as Mycobacterium marinum by colony growth rate and photochromogenicity and DNA sequencing. This is the first report of M. marinum infection in Japanese forest green tree frogs. PMID:25047922

  11. Epidemiology of endemic goitre in western Colombia

    PubMed Central

    Gaitan, E.; Merino, H.; Rodriguez, G.; Medina, P.; Meyer, J. D.; DeRouen, T. A.; MacLennan, R.

    1978-01-01

    This paper reports on recent epidemiological observations in western Colombia, which further demonstrate the presence of naturally-occurring goitrogens contaminating water supplies in areas where goitre persists despite prolonged and continuous iodine supplementation. 'Prospective' and 'cross-sectional' studies in 41 localities where the populations have been on a uniform and adequate iodine supplementation for the last 10-20 years indicate that, in the endemia of western Colombia, environmental factors other than nutritional iodine deficiency are responsible for differences in goitre prevalence. Further epidemiological studies to determine the causal factors for the persistence of the endemia established a correlation between the sources of drinking water and goitre prevalence rates. Organic compounds containing sulfur with marked thionamide-like antithyroid activity were isolated from water supplying endemic goitre districts, and results are presented supporting the hypothesis that sedimentary rocks rich in organic matter are the main source of water-borne goitrogens. Bacteriological investigations showed that the presence of Klebsiella pneumoniae in drinking water and bacterial concentration were related significantly with goitre prevalence only in the presence of other variables, particularly the presence of sedimentary rocks. In the light of these epidemiological observations and experimental studies it may be concluded that, at present, endemic goitre in western Colombia is not due to nutritional iodine deficiency, but that water supplies are contaminated with sulfur-bearing organic compounds with thionamide-like antithyroid activity most probably deriving from sedimentary rocks rich in organic matter and that these compounds are the main factor underlying the endemia. PMID:80287

  12. Evolution of advertisement calls in African clawed frogs

    PubMed Central

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

    2014-01-01

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

  13. Epigenetic silencers are enriched in dormant desert frog muscle.

    PubMed

    Hudson, Nicholas J; Lonhienne, T G A; Franklin, Craig E; Harper, Gregory S; Lehnert, S A

    2008-08-01

    Green-striped burrowing frogs, Cyclorana alboguttata, survive droughts by entering a metabolic depression called aestivation, characterised by a reduction in resting oxygen consumption by 80%. Aestivation in C. alboguttata is manifest by transcriptional silencing of skeletal muscle bioenergetic genes, such as NADH ubiquinone oxidoreductase 1, ATP synthase and superoxide dismutase 2. In this study, we hypothesised that aestivation is associated with epigenetic change in frog muscle. We assessed mRNA transcript abundance of seven genes that code for proteins with established roles in epigenetically-mediated gene silencing [transcriptional co-repressor SIN3A, DNA (cytosine-5-) methyltransferase 1, methyl CpG binding protein 2, chromodomain helicase DNA binding protein 4, histone binding protein rbbp4, histone deacetylase 1 and nuclear receptor co-repressor 2] using qRT-PCR. These seven genes showed a modest (1.1-3.5-fold) but coordinated upregulation in 6-month aestivating muscle. This reached significance for SIN3A and DNA cytosine-5-methyltransferase 1 in standard pair-wise comparisons (p < 0.05), and the candidates as a whole when analysed by Fisher's combined probability test (p < 0.01). These data are consistent with the hypothesis that the transcriptional silencing and metabolic depression that occurs during seasonal dormancy are associated with chromatin remodelling, and present a novel example of an environmentally induced epigenetic modification in an adult vertebrate. PMID:18369641

  14. Decreased winter severity increases viability of a montane frog population.

    PubMed

    McCaffery, Rebecca M; Maxell, Bryce A

    2010-05-11

    Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

  15. Chytridiomycosis in frogs of Mount Gede Pangrango, Indonesia.

    PubMed

    Kusrini, M D; Skerratt, L F; Garland, S; Berger, L; Endarwin, W

    2008-12-22

    Batrachochytrium dendrobatidis (Bd) is a fungus recognised as one of the causes of global amphibian population declines. To assess its occurrence, we conducted PCR diagnostic assays of 147 swab samples, from 13 species of frogs from Mount Gede Pangrango National Park, Indonesia. Four swab samples, from Rhacophorus javanus, Rana chalconota, Leptobrachium hasseltii and Limnonectes microdiscus, were positive for Bd and had low to moderate levels of infection. The sample from L. hasseltii was from a tadpole with mouthpart deformities and infection was confirmed by histology and immunohistochemistry. An additional sample from Leptophryne cruentata showed a very low level of infection (< or = 1 zoospore equivalent). This is the first record of Bd in Indonesia and in Southeast Asia, dramatically extending the global distribution of Bd, with important consequences for international amphibian disease control, conservation and trade. Consistent with declines in amphibian populations caused by Bd in other parts of the world, evidence exists for the decline and possible extirpation of amphibian populations at high elevations and some decline with recovery of populations at lower elevations on this mountain. Therefore, it is essential to manage Bd in Indonesia where it is likely to be threatening amphibian populations. This will require a national strategy to mitigate the spread of Bd in Indonesia and neighboring countries as well as the impact of that spread. It is also important to collect information on the extent of the impact of Bd on frog populations in Indonesia. PMID:19244970

  16. Octylphenol induced gene expression in testes of Frog, Rana chensinensis.

    PubMed

    Li, Xinyi; Liu, Jia; Zhang, Yuhui

    2016-06-01

    Octylphenol (OP) is an endocrine-disrupting chemical (EDC), which can disrupt the reproductive system. To understand the effect of OP, a subtractive cDNA library was constructed using suppression subtractive hybridization (SSH) to identify alterations of gene transcription in the testes of the frog Rana chensinensis after OP exposure. Two hundred positive clones were selected and 134 sequences of gene fragments were produced from the subtractive library randomly. These genes were identified to be involved in metabolic process, cellular process, biological regulation, stimulus, immune system and female pregnancy process. In order to verify the efficiency of the subtractive cDNA library, PSG9 and PAPP-A were analyzed further as two representatives of differentially expressed transcription genes using semi-quantitative RT-PCR. Our result was the first successful construction of the subtractive cDNA library in frog testes after OP treatment. Based on this cDNA library, OP was shown to affect multiple physiological processes including inducing immune response, disrupting the steroid hormone synthesis and influencing spermatogenesis in the testis by up-regulation of specific genes. PMID:26896894

  17. The regulation of volume and ion composition in frog skin.

    PubMed

    Ferreira, K T; Ferreira, H G

    1981-08-20

    1. Chemical determinations of Cl- in frog skin indicate that the intracellular concentration of this ion is above that corresponding to an equilibrium distribution. 2. Published data on Na+ efflux from the cell compartments into the two external bathing solutions, and on unidirectional fluxes across the whole preparation suggest that there are large unidirectional fluxes across the basolateral membranes. 3. Cl- uptake from the mucosal barrier is very small, and the removal of Cl- from the mucosal bathing solution does not affect the intracellular Cl- concentration. 4. Removal of Cl- from the serosal bathing solution produces a drastic decrease in cell Cl- together with a loss of water. 5. This is accompanied by a less marked effect on Na+ and K+ content of the cells. 6. The removal of Na+ from the serosal bathing solution produces also a decrease in Cl-, Na+ and K+ content of the cells with a marked loss of water. 7. It is suggested that the basolateral membrane of the frog skin is the site of mechanisms able to regulate volume and ion composition of the epithelial cells and that part of these mechanisms consists of a coupling between the movements of Na+ and Cl-. PMID:7295713

  18. Modeling neural adaptation in the frog auditory system

    NASA Astrophysics Data System (ADS)

    Wotton, Janine; McArthur, Kimberly; Bohara, Amit; Ferragamo, Michael; Megela Simmons, Andrea

    2005-09-01

    Extracellular recordings from the auditory midbrain, Torus semicircularis, of the leopard frog reveal a wide diversity of tuning patterns. Some cells seem to be well suited for time-based coding of signal envelope, and others for rate-based coding of signal frequency. Adaptation for ongoing stimuli plays a significant role in shaping the frequency-dependent response rate at different levels of the frog auditory system. Anuran auditory-nerve fibers are unusual in that they reveal frequency-dependent adaptation [A. L. Megela, J. Acoust. Soc. Am. 75, 1155-1162 (1984)], and therefore provide rate-based input. In order to examine the influence of these peripheral inputs on central responses, three layers of auditory neurons were modeled to examine short-term neural adaptation to pure tones and complex signals. The response of each neuron was simulated with a leaky integrate and fire model, and adaptation was implemented by means of an increasing threshold. Auditory-nerve fibers, dorsal medullary nucleus neurons, and toral cells were simulated and connected in three ascending layers. Modifying the adaptation properties of the peripheral fibers dramatically alters the response at the midbrain. [Work supported by NOHR to M.J.F.; Gustavus Presidential Scholarship to K.McA.; NIH DC05257 to A.M.S.

  19. PVC Pipe Samplers for Hylid Frogs: A Cautionary Note

    SciTech Connect

    MARTIN, FLOYD

    2004-04-07

    When such is available, many hylid frogs use artificial refugia, and this trait is frequently used as a basis for sampling populations of these frogs. Artificial refugia are any manmade objects that the animals may use for shelter (e.g. bird houses, bamboo stakes, lengths of pipe, etc.). By choosing refugia that the animals will readily enter and from which they may be easily removed, sampling can be directed toward particular species or size classes. Several variables have been considered when examining bias in sampling using these refugia. Among these variables are inside diameter of the pipes, pipe length, associated vegetation and height above ground. Our observations were not intended as an evaluation of polyvinyl chloride pipe traps as a sampling technique but rather were part of a study examining invertebrate and amphibian faunas associated with slope wetlands. Slope wetlands are wetlands formed where soil contours favor outcropping of water to the surface to form pools or channels often connected to streams. Despite the apparently small amount of appropriate data in this study, there are few enough quantified or semi-quantified data on this topic to be worth a cautionary note.

  20. Decreased winter severity increases viability of a montane frog population

    PubMed Central

    McCaffery, Rebecca M.; Maxell, Bryce A.

    2010-01-01

    Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

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

    USGS Publications Warehouse

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

    2012-01-01

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

  2. Ultrasonic frogs show hyperacute phonotaxis to female courtship calls.

    PubMed

    Shen, Jun-Xian; Feng, Albert S; Xu, Zhi-Min; Yu, Zu-Lin; Arch, Victoria S; Yu, Xin-Jian; Narins, Peter M

    2008-06-12

    Sound communication plays a vital role in frog reproduction, in which vocal advertisement is generally the domain of males. Females are typically silent, but in a few anuran species they can produce a feeble reciprocal call or rapping sounds during courtship. Males of concave-eared torrent frogs (Odorrana tormota) have demonstrated ultrasonic communication capacity. Although females of O. tormota have an unusually well-developed vocal production system, it is unclear whether or not they produce calls or are only passive partners in a communication system dominated by males. Here we show that before ovulation, gravid females of O. tormota emit calls that are distinct from males' advertisement calls, having higher fundamental frequencies and harmonics and shorter call duration. In the field and in a quiet, darkened indoor arena, these female calls evoke vocalizations and extraordinarily precise positive phonotaxis (a localization error of <1 degrees ), rivalling that of vertebrates with the highest localization acuity (barn owls, dolphins, elephants and humans). The localization accuracy of O. tormota is remarkable in light of their small head size (interaural distance of <1 cm), and suggests an additional selective advantage of high-frequency hearing beyond the ability to avoid masking by low-frequency background noise. PMID:18469804

  3. Female Túngara Frogs do not Experience the Continuity Illusion

    PubMed Central

    Baugh, Alexander T.; Ryan, Michael J.; Bernal, Ximena E.; Rand, A. Stanley; Bee, Mark A.

    2015-01-01

    In humans and some non-human vertebrates, a sound containing brief silent gaps can be rendered perceptually continuous by inserting noise into the gaps. This so-called ‘continuity illusion’ arises from a phenomenon known as ‘auditory induction’ and results in the perception of complete auditory objects despite fragmentary or incomplete acoustic information. Previous studies of auditory induction in gray treefrogs (Hyla versicolor and H. chrysoscelis) have demonstrated an absence of this phenomenon. These treefrog species produce pulsatile (non-continuous) vocalizations, whereas studies of auditory induction in other taxa, including humans, often present continuous sounds (e.g., frequency-modulated sweeps). This study investigated the continuity illusion in a frog (Physalaemus pustulosus) with an advertisement vocalization that is naturally continuous and thus similar to the tonal sweeps used in human psychophysical studies of auditory induction. In a series of playback experiments, female subjects were presented with sets of stimuli that included complete calls, calls with silent gaps, and calls with silent gaps filled with noise. The results failed to provide evidence of auditory induction. Current evidence, therefore, suggests that mammals and birds experience auditory induction, but frogs may not. This emerging pattern of taxonomic differences is considered in light of potential methodological, neurophysiological, and functional explanations. PMID:26692450

  4. Evolution of advertisement calls in African clawed frogs.

    PubMed

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

    2011-01-01

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

  5. Potassium influx in the frog atrium during the cardiac cycle.

    PubMed

    Juncker, D F; Lee, P Y; Greene, E A; Stish, R; Lorber, V

    1975-11-01

    A method for measuring inwardly directed transmembrane tracer flow during the cardiac cycle was developed and applied to a study of 42K influx in frog atrial trabeculae. A fine frog atrial fiber was suspended in a stream of nonisotopic perfusate into which a smaller tracer-containing bolus could be injected, subjecting the fiber to a brief, controlled exposure to the tracer at any desired point in the cardiac cycle. In an experiment, the tissue was exposed to a fixed number of radioactive pulses at a selected point in the cardiac cycle; a brief flush with nonradioactive perfusate removed ambient and extracellular label and an extended wash and removed the remaining intracellular tracer for radioassay. The same procedure was repeated at different points in the cycle, and the resulting tracer uptake at each point measured the relative influx of the particular ion. In this way, a characteristic and reproducible 42K influx profile was demonstrated which exhibited a marked drop below diastolic values during the first 500 msec or so of the action potential followed by a rise and an overshoot above resting values. The time of return to the resting level was somewhat uncertain but was tentatively placed in the vicinity of rapid repolarization. We suggest that the rise and the overshoot reflect the activity of the membrane Na+, K+-adenosinetriphosphatase. PMID:1081436

  6. Sperm competition and the evolution of gamete morphology in frogs.

    PubMed

    Byrne, Phillip G; Simmons, Leigh W; Roberts, J Dale

    2003-10-01

    Despite detailed knowledge of the ultrastructure of spermatozoa, there is a paucity of information on the selective pressures that influence sperm form and function. Theoretical models for both internal and external fertilizers predict that sperm competition could favour the evolution of longer sperm. Empirical tests of the external-fertilization model have been restricted to just one group, the fishes, and these tests have proved equivocal. We investigated how sperm competition affects sperm morphology in externally fertilizing myobatrachid frogs. We also examined selection acting on egg size, and covariation between sperm and egg morphology. Species were ranked according to probability of group spawning and hence risk of sperm competition. Body size, testis size and oviposition environment may also influence gamete traits and were included in our analyses. After controlling for phylogenetic relationships between the species examined, we found that an increased risk of sperm competition was associated with increased sperm head and tail lengths. Path analysis showed that sperm competition had its greatest direct effect on sperm tail length, as might be expected under selection resulting from competitive fertilization. Sperm competition did not influence egg size. Oviposition location had a strong influence on egg size and a weak influence on sperm length, with terrestrial spawners having larger gametes than aquatic spawners. Our analysis revealed significant correlated evolution between egg morphology and sperm morphology. These data provide a conclusive demonstration that sperm competition selects for increased sperm length in frogs, and evidence for evolutionary covariance between aspects of male and female gamete morphology. PMID:14561298

  7. High levels of cryptic species diversity uncovered in Amazonian frogs

    PubMed Central

    Funk, W. Chris; Caminer, Marcel; Ron, Santiago R.

    2012-01-01

    One of the greatest challenges for biodiversity conservation is the poor understanding of species diversity. Molecular methods have dramatically improved our ability to uncover cryptic species, but the magnitude of cryptic diversity remains unknown, particularly in diverse tropical regions such as the Amazon Basin. Uncovering cryptic diversity in amphibians is particularly pressing because amphibians are going extinct globally at an alarming rate. Here, we use an integrative analysis of two independent Amazonian frog clades, Engystomops toadlets and Hypsiboas treefrogs, to test whether species richness is underestimated and, if so, by how much. We sampled intensively in six countries with a focus in Ecuador (Engystomops: 252 individuals from 36 localities; Hypsiboas: 208 individuals from 65 localities) and combined mitochondrial DNA, nuclear DNA, morphological, and bioacoustic data to detect cryptic species. We found that in both clades, species richness was severely underestimated, with more undescribed species than described species. In Engystomops, the two currently recognized species are actually five to seven species (a 150–250% increase in species richness); in Hypsiboas, two recognized species represent six to nine species (a 200–350% increase). Our results suggest that Amazonian frog biodiversity is much more severely underestimated than previously thought. PMID:22130600

  8. Mycotic Infections Acquired outside Areas of Known Endemicity, United States

    PubMed Central

    Thompson, George R.; Deresinski, Stan; Chiller, Tom

    2015-01-01

    In the United States, endemic mycoses—blastomycosis, coccidioidomycosis, and histoplasmosis—pose considerable clinical and public health challenges. Although the causative fungi typically exist within broadly defined geographic areas or ecologic niches, some evidence suggests that cases have occurred in humans and animals not exposed to these areas. We describe cases acquired outside regions of traditionally defined endemicity. These patients often have severe disease, but diagnosis may be delayed because of a low index of suspicion for mycotic disease, and many more cases probably go entirely undetected. Increased awareness of these diseases, with a specific focus on their potential occurrence in unusual areas, is needed. Continued interdisciplinary efforts to reevaluate and better describe areas of true endemicity are warranted, along with a more nuanced view of the notion of endemicity. The term “nonendemic” should be used with care; mycoses in such regions might more accurately be considered “not known to be endemic.” PMID:26485441

  9. Mycotic Infections Acquired outside Areas of Known Endemicity, United States.

    PubMed

    Benedict, Kaitlin; Thompson, George R; Deresinski, Stan; Chiller, Tom

    2015-11-01

    In the United States, endemic mycoses--blastomycosis, coccidioidomycosis, and histoplasmosis--pose considerable clinical and public health challenges. Although the causative fungi typically exist within broadly defined geographic areas or ecologic niches, some evidence suggests that cases have occurred in humans and animals not exposed to these areas. We describe cases acquired outside regions of traditionally defined endemicity. These patients often have severe disease, but diagnosis may be delayed because of a low index of suspicion for mycotic disease, and many more cases probably go entirely undetected. Increased awareness of these diseases, with a specific focus on their potential occurrence in unusual areas, is needed. Continued interdisciplinary efforts to reevaluate and better describe areas of true endemicity are warranted, along with a more nuanced view of the notion of endemicity. The term "nonendemic" should be used with care; mycoses in such regions might more accurately be considered "not known to be endemic." PMID:26485441

  10. Chemotherapeutics challenges in developing effective treatments for the endemic malarias.

    PubMed

    Kevin Baird, J

    2012-12-01

    The endemic malarias threaten the several billion people residing where transmission occurs. Chemotherapeutic strategy pitted against these threats hinges upon species- and stage-specific treatments guided by diagnosis and screening against sometime dangerous contraindications. This approach suits malaria as it occurs among travelers in the developed, non-endemic world. However, limiting treatment to that which diagnosis affirms may not be rational in endemic zones. Most of the endemic malarias remain out of diagnostic reach, either by inaccessibility of the parasite stage, insensitivity of the technology, or unavailability of diagnostic services. The partial and fragmented chemotherapeutic attack of malaria guided by confirmed diagnostics leaves most of the endemic malarias unchallenged. Development of elimination therapy, a single course of treatment aimed at all species and stages, would significantly advance progress against the major killers known collectively as malaria. PMID:24533286

  11. A field evaluation of frogs as a potential source of secondary organophosphorus insecticide poisoning

    USGS Publications Warehouse

    Powell, G.V.N.; DeWeese, L.R.; Lamont, T.G.

    1982-01-01

    Because amphibians are relatively resistant to organophosphorus insecticides and can bioaccumulate residues to high levels, they may be a source of secondary poisoning for vertebrates that feed on them. This hypothesis was tested by determining residues in breeding upland chorus frogs Pseudacris triseriata, that were collected from ponds treated with the organophosphorus insecticide fenthion. Frogs were collected up to 3-days posttreatment in four areas that were treated with fenthion formulated in either diesel oil or water. No residues of fenthion were detected above the 0.01 ppm level of analytical sensitivity. These results indicate that the frogs were not a likely source of secondary poisoning for predatory vertebrates.

  12. Frequency-Selective Response of the Tectorial Membrane in the Frog Basilar Papilla

    NASA Astrophysics Data System (ADS)

    Schoffelen, R. L. M.; Segenhout, J. M.; van Dijk, P.

    2009-02-01

    The frog's basilar papilla is a useful study object for cochlear mechanics, because of it's relatively simple anatomy and functionality. We investigated the displacement amplitudes of the basilar papilla's tectorial membrane in response to stimulation of the oval window at various frequencies within the auditory range of the Northern leopard frog. From our measurement data we find that the tectorial membrane exhibits a frequency selective response. The peak response was found to occur at 1500Hz in correspondence with known data for the response of auditory nerve fibers from the organ. From these data we conclude that mechanical tuning contributes significantly to the frequency selectivity of the frog's basilar papilla

  13. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    USGS Publications Warehouse

    Gregoire, D.R.; Gunzburger, M.S.

    2008-01-01

    Southern Leopard Frogs, Rana sphenocephala, are habitat generalists occurring in virtually all freshwater habitats within their geographic range, whereas Gopher Frogs, Rana capito, typically breed in ponds that do not normally contain fish. To evaluate the potential for predation by fish to influence the distribution of these species, we conducted a randomized factorial experiment. We examined the survival rate and behavior of tadpoles when exposed to Warmouth Sunfish, Lepomis gulosus, Banded Sunfish, Enneacanthus obesus, and Eastern Mosquitofish, Gambusia holbrooki. We also conducted a choice experiment to examine the survival rate of the two species of tadpoles when a predator is given a choice of both species simultaneously. Lepomis gulosus consumed the most tadpoles and ate significantly more tadpoles of R. capito than R. sphenocephala. Gambusia holbrooki injured the most tadpoles, especially R. capito. Enneacanthus obesus did not have an effect on behavior or survival of either anuran species. Tadpoles of both anurans increased hiding when in the presence of L. gulosus and G. holbrooki, but a greater proportion of R. capito hid than did R. sphenocephala. Our results suggest that R. capito are more vulnerable to predation by fish than are R. sphenocephala. The introduction of fish may play a role in population declines of certain anurans breeding in normally fish-free wetlands, and even small fish, such as mosquitofish, may have significant negative effects on the tadpoles of R. capito. Copyright 2008 Society for the Study or Amphibians and Reptiles.

  14. Transitions between Andean and Amazonian centers of endemism in the radiation of some arboreal rodents

    PubMed Central

    2013-01-01

    Background The tropical Andes and Amazon are among the richest regions of endemism for mammals, and each has given rise to extensive in situ radiations. Various animal lineages have radiated ex situ after colonizing one of these regions from the other: Amazonian clades of dendrobatid frogs and passerine birds may have Andean ancestry, and transitions from the Amazon to Andes may be even more common. To examine biogeographic transitions between these regions, we investigated the evolutionary history of three clades of rodents in the family Echimyidae: bamboo rats (Dactylomys-Olallamys-Kannabateomys), spiny tree-rats (Mesomys-Lonchothrix), and brush-tailed rats (Isothrix). Each clade is distributed in both the Andes and Amazonia, and is more diverse in the lowlands. We used two mitochondrial (cyt-b and 12S) and three nuclear (GHR, vWF, and RAG1) markers to reconstruct their phylogenetic relationships. Tree topologies and ancestral geographic ranges were then used to determine whether Andean forms were basal to or derived from lowland radiations. Results Four biogeographic transitions are identified among the generic radiations. The bamboo rat clade unambiguously originated in the Amazon ca. 9 Ma, followed by either one early transition to the Andes (Olallamys) and a later move to the Amazon (Dactylomys), or two later shifts to the Andes (one in each genus). The Andean species of both Dactylomys and Isothrix are sister to their lowland species, raising the possibility that highland forms colonized the Amazon Basin. However, uncertainty in their reconstructed ancestral ranges obscures the origin of these transitions. The lone Andean species of Mesomys is confidently nested within the lowland radiation, thereby indicating an Amazon-to-Andes transition ca. 2 Ma. Conclusions Differences in the timing of these biogeographic transitions do not appear to explain the different polarities of these trees. Instead, even within the radiation of a single family, both Andean and

  15. Adaptive Grouping Cloud Model Shuffled Frog Leaping Algorithm for Solving Continuous Optimization Problems

    PubMed Central

    Liu, Haorui; Yi, Fengyan; Yang, Heli

    2016-01-01

    The shuffled frog leaping algorithm (SFLA) easily falls into local optimum when it solves multioptimum function optimization problem, which impacts the accuracy and convergence speed. Therefore this paper presents grouped SFLA for solving continuous optimization problems combined with the excellent characteristics of cloud model transformation between qualitative and quantitative research. The algorithm divides the definition domain into several groups and gives each group a set of frogs. Frogs of each region search in their memeplex, and in the search process the algorithm uses the “elite strategy” to update the location information of existing elite frogs through cloud model algorithm. This method narrows the searching space and it can effectively improve the situation of a local optimum; thus convergence speed and accuracy can be significantly improved. The results of computer simulation confirm this conclusion. PMID:26819584

  16. DEVELOPMENTAL MALFORMATION OF FROG EMBRYOS: AN ANALYSIS OF TERATOGENICITY OF CHEMICAL MIXTURES

    EPA Science Inventory

    Chemical compounds known to be teratogenic to frog embryos were tested singly and in binary mixtures and Weibull functions were used to model their concentration response relationships. eparate Weibull function with an additive concentration variable modeled the mixtures using on...

  17. PHENOBARBITAL AFFECTS THYROID HISTOLOGY AND LARVAL DEVELOPMENT IN THE AFRICAN CLAWED FROG XENOPUS LAEVIS

    EPA Science Inventory

    The abstract highlights our recent study to explore endocrine disrupting effects of phenobarbital in the African clawed frog, Xenopus laevis. In mammals, this chemical is known to induce the biotransforming enzyme UDP-glucuronosyltransferase (UDPGT) resulting in increased thyroid...

  18. Phase Reconstruction from FROG Using Genetic Algorithms[Frequency-Resolved Optical Gating

    SciTech Connect

    Omenetto, F.G.; Nicholson, J.W.; Funk, D.J.; Taylor, A.J.

    1999-04-12

    The authors describe a new technique for obtaining the phase and electric field from FROG measurements using genetic algorithms. Frequency-Resolved Optical Gating (FROG) has gained prominence as a technique for characterizing ultrashort pulses. FROG consists of a spectrally resolved autocorrelation of the pulse to be measured. Typically a combination of iterative algorithms is used, applying constraints from experimental data, and alternating between the time and frequency domain, in order to retrieve an optical pulse. The authors have developed a new approach to retrieving the intensity and phase from FROG data using a genetic algorithm (GA). A GA is a general parallel search technique that operates on a population of potential solutions simultaneously. Operators in a genetic algorithm, such as crossover, selection, and mutation are based on ideas taken from evolution.

  19. Semaphoring in an earless frog: the origin of a novel visual signal.

    PubMed

    Lindquist, E D; Hetherington, T E

    1998-10-01

    Social communication in anuran amphibians (frogs and toads) is mediated predominantly by acoustic signals. Unlike most anurans, the Panamanian golden frog, Atelopus zeteki, lacks a standard tympanic middle ear and appears to have augmented its communicatory repertoire to include rotational limb motions as visual signals, referred to here as semaphores. The communicatory nature of semaphoring was inferred from experimental manipulations using mirrored self-image presentations and nonresident introductions. Male frogs semaphored significantly more when presented with a mirrored self-image than with a nonreflective control. Novel encounters between resident males and nonresident frogs demonstrated that semaphores were used directionally and were displayed toward target individuals. Females semaphored frequently and this observation represents a rare case of signaling by females in a typically male-biased communicatory regime. Semaphore actions were clearly linked to a locomotory gait pattern and appear to have originated as an elaboration of a standard stepping motion. PMID:24399272

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

    SciTech Connect

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

    1989-01-01

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

  1. Updated Global Burden of Cholera in Endemic Countries

    PubMed Central

    Ali, Mohammad; Nelson, Allyson R.; Lopez, Anna Lena; Sack, David A.

    2015-01-01

    Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control. PMID:26043000

  2. Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

    PubMed

    Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

    2011-04-15

    Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species. PMID:20933347

  3. Temporal stability of an endemic Mexican treefrog

    PubMed Central

    Cruz-Ruiz, Griselda; Venegas-Barrera, Crystian S.; Sanchez-Sanchez, Hermilo

    2015-01-01

    The demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the size of an amphibian population and could be used to determine the current conservation status of a species. During a five year (2004–2008) period, we studied the relative abundance, sex ratio, and age-sex structure of a population of metamorphosed individuals of the endemic treefrog Hyla eximia in Central Mexico. We also studied the species’ relationship with climatic variables such as temperature and precipitation. We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with decreased abundance of males and juveniles during the rainy months (August–November). The annual abundance of H. eximia was positively correlated with rainfall, but negatively with monthly temperature. We found the sex ratio was male-biased (2:1), except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals. We conclude that variations in abundance, and frequencies by age-sex category, of H. eximia are related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change. PMID:26421242

  4. [The endemic goitre in figurative arts].

    PubMed

    Giampalmo, A

    1996-01-01

    For the past fifteen years the author has been collecting photografic documentation of works of figurative arts (graffiti, mosiac, engravings, paintings and sculptures) made at different times and places, in which he found mostly unintentional display of diseases or deformities that would be clearly identified in nosography in the light of today's knowledge. In this study the author intends to illustrate briefly different cases on endemic goitre - whose representation is particularly frequent in figurative arts - in chronological order, beginning with the most ancient ones and focussing on Italian portraying of the Nativity and the Passion of Christ, where the most striking infirmities and disabilities were mirrored and commonly accepted. This study whose interest lies between a scientific and a humanistic one has also importance in the field of art, and especially in relevant philological research which is of particular importance to us pathologists. At last it contribute to establish the epidemiology of some diseases and the knowledge of historical and geographical pathology. PMID:11623474

  5. Endemic transmission of visceral leishmaniasis in Bhutan.

    PubMed

    Yangzom, Thinley; Cruz, Israel; Bern, Caryn; Argaw, Daniel; den Boer, Margriet; Vélez, Iván Dario; Bhattacharya, Sujit K; Molina, Ricardo; Alvar, Jorge

    2012-12-01

    Visceral leishmaniasis was first reported in Bhutan in 2006. We conducted studies of the parasite, possible vectors and reservoirs, and leishmanin skin test and risk factor surveys in three villages. Nineteen cases were reported from seven districts. Parasite typing yielded two novel microsatellite sequences, both related to Indian L. donovani. In one case village, 40 (18.5%) of 216 participants had positive leishmanin skin test results, compared with 3 (4.2%) of 72 in the other case village and 0 of 108 in the control village. Positive results were strongly associated with the village and increasing age. None of the tested dogs were infected. Eighteen sand flies were collected, 13 Phlebotomus species and 5 Sergentomyia species; polymerase chain reaction for leishmanial DNA was negative. This assessment suggests that endemic visceral leishmaniasis transmission has occurred in diverse locations in Bhutan. Surveillance, case investigations, and further parasite, vector, and reservoir studies are needed. The potential protective impact of bed nets should be evaluated. PMID:23091191

  6. Temporal stability of an endemic Mexican treefrog.

    PubMed

    Cruz-Ruiz, Griselda; Venegas-Barrera, Crystian S; Sanchez-Sanchez, Hermilo; Manjarrez, Javier

    2015-01-01

    The demographic characteristics of an amphibian population fluctuate independently over time, mainly in response to the temporal variation of environmental factors, especially precipitation and temperature. These temporal fluctuations may contribute to the size of an amphibian population and could be used to determine the current conservation status of a species. During a five year (2004-2008) period, we studied the relative abundance, sex ratio, and age-sex structure of a population of metamorphosed individuals of the endemic treefrog Hyla eximia in Central Mexico. We also studied the species' relationship with climatic variables such as temperature and precipitation. We found an interannual constant abundance during the study period. However, interannual differences were observed in the population structure by age-sex category (males, females, or juveniles), with decreased abundance of males and juveniles during the rainy months (August-November). The annual abundance of H. eximia was positively correlated with rainfall, but negatively with monthly temperature. We found the sex ratio was male-biased (2:1), except for year 2008. Also, differences in snout-vent length (SVL) were found between years, suggesting changes in recruitment of new individuals. We conclude that variations in abundance, and frequencies by age-sex category, of H. eximia are related to seasonal variations in temperature and precipitation characteristics of temperate zones. However, this temporal stability may suggest that anurans have an unusual capacity to persist even in the face of human-induced habitat change. PMID:26421242

  7. Density dependent growth in adult brown frogs Rana arvalis and Rana temporaria - A field experiment

    NASA Astrophysics Data System (ADS)

    Loman, Jon; Lardner, Björn

    2009-11-01

    In species with complex life cycles, density regulation can operate on any of the stages. In frogs there are almost no studies of density effects on the performance of adult frogs in the terrestrial habitat. We therefore studied the effect of summer density on the growth rate of adult frogs during four years. Four 30 by 30 m plots in a moist meadow were used. In early summer, when settled after post-breeding migration, frogs ( Rana arvalis and Rana temporaria that have a very similar ecology and potentially compete) were enclosed by erecting a fence around the plots. Frogs were captured, measured, marked and partly relocated to create two high density and two low density plots. In early autumn the frogs were again captured and their individual summer growth determined. Growth effects were evaluated in relation to two density measures: density by design (high/low manipulation), and actual (numerical) density. R. arvalis in plots with low density by design grew faster than those in high density plots. No such effect was found for R. temporaria. For none of the species was growth related to actual summer density, determined by the Lincoln index and including the density manipulation. The result suggests that R. arvalis initially settled according to an ideal free distribution and that density had a regulatory effect (mediated through growth). The fact that there were no density effects on R. temporaria (and a significant difference in its response to that of R. arvalis) suggests it is a superior competitor to R. arvalis during the terrestrial phase. There were no density effects on frog condition index, suggesting that the growth rate modifications may actually be an adaptive trait of R. arvalis. The study demonstrates that density regulation may be dependent on resources in frogs' summer habitat.

  8. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen

    PubMed Central

    Savage, Anna E.; Terrell, Kimberly A.; Gratwicke, Brian; Mattheus, Nichole M.; Augustine, Lauren; Fleischer, Robert C.

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1–15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29–55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations. PMID:27293759

  9. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen.

    PubMed

    Savage, Anna E; Terrell, Kimberly A; Gratwicke, Brian; Mattheus, Nichole M; Augustine, Lauren; Fleischer, Robert C

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1-15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29-55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations. PMID:27293759

  10. Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A

    USGS Publications Warehouse

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.

    2000-01-01

    Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of

  11. Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

    USGS Publications Warehouse

    Germaine, S.S.; Hays, D.W.

    2009-01-01

    Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002-2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.

  12. Evaluation of Antimicrobial and Healing Activities of Frog Skin on Guinea Pigs Wounds

    PubMed Central

    Rezazade Bazaz, Mahere; Mashreghi, Mohammad; Mahdavi Shahri, Nasser; Mashreghi, Mansour; Asoodeh, Ahmad; Behnam Rassouli, Morteza

    2015-01-01

    Background: Frog skin secretions have potentials against a wide spectrum of bacteria. Also, frog skin compositions have healing properties. Objectives: The aim of this study was to investigate the antibacterial potentials along with healing properties of frog skin Rana ridibunda, a species which thoroughly lives in Iran marshes, as a biological dressing on wounds. Materials and Methods: In this study, excisional wounds, dressed with frog skin, were compared between experimental and control groups of guinea pigs. In the experimental groups, wounds were dressed with the dermal (FS) and epidermal (RFS) sides of fresh frog R. ridibunda skin, while only usual cotton gauze covered the wounds of the control group. Furthermore, microbial samples were taken on different days (0, 3, 5, and 7 days post injury) to count the number of the colony-forming units. Additionally, the microbial penetration test was performed on frog skin and then the progression of wound closure was evaluated. Results: In the microbial studies, the bacterial load considerably declined in the wounds treated with FS and RFS compared with the control wounds. On day 7 post injury, the numbers of the colony-forming units for the FS, RFS, and control groups were 6.75, 105, and 375, respectively. In the penetration test, fresh frog skin showed to be a bacterial resistant dressing. The results revealed that the rate of wound closure in the experimental groups significantly was accelerated in comparison with that in the control group. Conclusions: Our results demonstrated the antimicrobial properties of frog skin as a wound dressing, which has antimicrobial effects per se. This biological dressing shows promise as an effective biological wound dressing insofar as not only is it capable of resisting microbes and accelerating wound healing but also it is cost-effective and easy to use. PMID:26468364

  13. Metabolic fate of lactate after vigorous activity in the leopard frog, Rana pipiens.

    PubMed

    Fournier, P A; Guderley, H

    1992-02-01

    Although the ability of isolated frog muscle to synthesize glycogen from lactate has long been known, it has never been demonstrated that this metabolic activity occurs in the intact frog. Our results clearly indicate that lactate glycogenesis in frog muscle occurs to a significant extent in vivo. During recovery from strenuous exercise, most of the lactate accumulated by frogs seems to be recycled into muscle glycogen because the lactate that disappears during recovery could account nearly stoichiometrically for the glycogen that accumulates in muscle. Furthermore, the decrease in body lactate and the increase in muscle glycogen follow corresponding time courses, suggesting a precursor-product relationship between lactate and glycogen. During recovery from intense exercise, hepatectomized and normal frogs have nearly identical extents of lactate elimination and glycogen synthesis. This suggests that muscle is the main tissue responsible for the recycling of lactate into muscle glycogen and that liver plays a negligible role in lactate disposal. The negligible hepatic contribution to lactate recycling results in part from the liver's incapacity to produce glucose from lactate. In support of this proposition, we show that frog liver perfused in vitro is unable to incorporate any detectable labeled lactate into glucose despite its excellent physiological integrity. Changes in dietary status, training state, season at which the experiments were done, exercise status, and composition of the perfusion media (pH, hormonal composition, physiological saline vs. culture medium) did not give rise to lactate gluconeogenesis. Because frog liver contains all the regulatory enzymes of the gluconeogenic pathway, its inability to synthesize glucose from lactate is not due to an absence of pyruvate carboxylase. A limited ability for lactate uptake may explain why frog liver cannot produce glucose from lactate. PMID:1539733

  14. A new species of limestone karst inhabiting forest frog, genus Platymantis (Amphibia: Anura: Ceratobatrachidae: subgenus Lupacolus) from southern Luzon Island, Philippines.

    PubMed

    Brown, Rafe M; De Layola, Louise Abigail; Lorenzo, Antonio; Diesmos, Mae Lowe L; Diesmos, Arvin C

    2015-01-01

    We describe a new species of limestone karst dwelling forest frog of the genus Platymantis from the Quezon Protected Landscape in southeastern Luzon Island, Philippines. We assign Platymantis quezoni, sp. nov., to the diverse assemblage of terrestrial species in the Platymantis dorsalis Group, subgenus Lupacolus on the basis of its body size and proportions, only slightly expanded terminal discs of the fingers and toes, and its terrestrial microhabitat. The new species is distinguished from these and all other Philippine congeners by features of its external morphology, its restriction to a distinctive limestone karst microhabitat, and its advertisement call, which is unique among frogs of the family Ceratobatrachidae. Several distinguishing morphological characters include its moderate body size (22.1-33.9 mm SVL for 16 adult males and 32.4-39.7 mm SVL for five adult females), slightly expanded terminal discs of the fingers and toes, smooth skin with limited dermal tuberculation, and a dorsal color pattern of mottled tan to dark brown with black blotches. The new species is the sixth Philippine Platymantis known to occur exclusively on limestone karst substrates (previously known karst-obligate species include: P. bayani, P. biak, P. insulatus, P. paengi, and P. speleaus). Recently accelerated discovery of limestone karst anurans across the Philippines suggests that numerous additional species may await discovery on the hundreds of scattered karst formations throughout the archipelago. This possibility suggests that a major conservation priority in coming years will be to study, characterize, describe, and preserve the endemic species supported by this patchy, unique and imperiled type of forest ecosystem in the Philippines. PMID:26624745

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

    PubMed Central

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

    2009-01-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike. PMID:24575178

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

    PubMed

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

    2009-12-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike. PMID:24575178

  17. Evaluating group housing strategies for the ex-situ conservation of harlequin frogs (Atelopus spp.) using behavioral and physiological indicators.

    PubMed

    Cikanek, Shawna J; Nockold, Simon; Brown, Janine L; Carpenter, James W; Estrada, Angie; Guerrel, Jorge; Hope, Katharine; Ibáñez, Roberto; Putman, Sarah B; Gratwicke, Brian

    2014-01-01

    We have established ex situ assurance colonies of two endangered Panamanian harlequin frogs, Atelopus certus and Atelopus glyphus, but observed that males fought with each other when housed as a group. Housing frogs individually eliminated this problem, but created space constraints. To evaluate the potential stress effects from aggressive interactions when grouping frogs, we housed male frogs in replicated groups of one, two, and eight. We measured aggressive behavioral interactions and fecal glucocorticoid metabolite (GC) concentrations as indicators of stress in each tank. In both small and large groups, frogs initially interacted aggressively, but aggressive interactions and fecal GCs declined significantly after the first 2 weeks of being housed together, reaching the lowest levels by week 4. We conclude that aggressive interactions in same-sex groups of captive Atelopus may initially cause stress, but the frogs become habituated within a few weeks and they can safely be housed in same-sex groups for longer periods of time. PMID:24587290

  18. Evaluating Group Housing Strategies for the Ex-Situ Conservation of Harlequin Frogs (Atelopus spp.) Using Behavioral and Physiological Indicators

    PubMed Central

    Cikanek, Shawna J.; Nockold, Simon; Brown, Janine L.; Carpenter, James W.; Estrada, Angie; Guerrel, Jorge; Hope, Katharine; Ibáñez, Roberto; Putman, Sarah B.; Gratwicke, Brian

    2014-01-01

    We have established ex situ assurance colonies of two endangered Panamanian harlequin frogs, Atelopus certus and Atelopus glyphus, but observed that males fought with each other when housed as a group. Housing frogs individually eliminated this problem, but created space constraints. To evaluate the potential stress effects from aggressive interactions when grouping frogs, we housed male frogs in replicated groups of one, two, and eight. We measured aggressive behavioral interactions and fecal glucocorticoid metabolite (GC) concentrations as indicators of stress in each tank. In both small and large groups, frogs initially interacted aggressively, but aggressive interactions and fecal GCs declined significantly after the first 2 weeks of being housed together, reaching the lowest levels by week 4. We conclude that aggressive interactions in same-sex groups of captive Atelopus may initially cause stress, but the frogs become habituated within a few weeks and they can safely be housed in same-sex groups for longer periods of time. PMID:24587290

  19. Chytridiomycosis in wild frogs from southern Costa Rica

    USGS Publications Warehouse

    Lips, Karen R.; Green, D.E.; Papendick, R.

    2003-01-01

    In 1993, the amphibian fauna of Las Tablas, Costa Rica, began to decline, and by 1998 approximately 50% of the species formerly present could no longer be found. Three years later, at the Reserva Forestal Fortuna, in western Panama, a site approximately 75 km east southeast of Las Tablas, KRL encountered a mass die-off of amphibians and a subsequent decline in abundance and species richness. The epidemiological features of the anuran population declines and die-offs at both sites were similar, suggesting a similar cause. Herein we document the presence of the fungus, Batrachochytrium dendrobatidis, in dead and dying wild frogs collected at Las Tablas just prior to population declines of several anuran species.

  20. Odorant-evoked potassium changes in the frog olfactory epithelium.

    PubMed

    Khayari, A; Math, F; Trotier, D

    1991-01-18

    Electroolfactogram (EOG) and extracellular potassium activity (aK) measurements were carried out in frog olfactory epithelia in vivo. Odorant-evoked changes in aK were characterized on the basis of depth profile analysis. Following an olfactory stimulation with butanol vapours, an increase in aK was measured in the mucus and the proximal part of the epithelium; this response started after the beginning of the EOG and was proportional to the amplitude of the latter. In the deeper part of the epithelium, the aK response had complex waveforms showing an initial K decrease which was suppressed by local application of ouabain, suggesting the existence of a pumping mechanism at this level. The results are discussed in terms of extracellular accumulation of K ions following neuroreceptor activation with respect to EOG generation theories. PMID:2015495

  1. Proton Nuclear Magnetic Resonance Relaxation Measurements in Frog Muscle

    PubMed Central

    Finch, Edward D.; Homer, Louis D.

    1974-01-01

    Proton nuclear magnetic resonance (NMR) relaxation measurements are reported for frog muscle as a function of temperature and Larmor frequency. Each T1ρ, T2, and T1 measurement covered a time domain sufficient to identify the average relaxation time for most intracellular water. Using regression analysis the data were fit with a model where intracellular water molecules are exchanging between a large compartment in which mobility is similar to ordinary water and a small compartment in which motion is restricted. The regression results suggest that: the restricted compartment exhibits a distribution of motions skewed toward that of free water; the residence time of water molecules in the restricted compartment is approximately 1 ms; and, the activation entropy for some water molecules in the restricted compartment is negative. PMID:4547668

  2. BIG FROG WILDERNESS STUDY AREA AND ADDITIONS, TENNESSEE AND GEORGIA.

    USGS Publications Warehouse

    Slack, John F.; Gazdik, Gertrude C.

    1984-01-01

    A mineral-resource survey was made of the Big Frog Wilderness Study Area and additions, Tennessee-Georgia. Geochemical sampling found traces of gold, zinc, copper, and arsenic in rocks, stream sediments, and panned concentrates, but not in sufficient quantities to indicate the presence of deposits of these metals. The results of the survey indicate that there is little promise for the occurrence of metallic mineral deposits within the study area. The only apparent resources are nonmetallic commodities including rock suitable for construction materials, and small amounts of sand and gravel; however, these commodities are found in abundance outside the study area. A potential may exist for oil and natural gas at great depths, but this cannot be evaluated by the present study.

  3. Cutaneus myxosporidiasis in the Australian green tree frog (Litoria caerulea)

    PubMed Central

    Tomczuk, Krzysztof; Studzińska, Maria

    2010-01-01

    This case is reported with the intention of highlighting the presentation of cutaneous myxosporidiasis in Australian tree frog (Litoria caerulea) caused by genus Myxobolus. The morphology and morphometric characteristic of the spores were determined using light microscopy and differential interference contrast microscopy. Spores were pyriform in shape in frontal view and oval in lateral view, and the average size was respectively 11.4 × 6.0 × 4.5 μm (12.1 − 9.5 × 6.3 − 5.4 × 5.0 − 4.1 μm). To the best of our knowledge, this is the second case of skin invasion caused by myxosporeans in amphibians. PMID:20922417

  4. How minute sooglossid frogs hear without a middle ear

    PubMed Central

    Boistel, Renaud; Aubin, Thierry; Cloetens, Peter; Peyrin, Françoise; Scotti, Thierry; Herzog, Philippe; Gerlach, Justin; Pollet, Nicolas; Aubry, Jean-François

    2013-01-01

    Acoustic communication is widespread in animals. According to the sensory drive hypothesis [Endler JA (1993) Philos Trans R Soc Lond B Biol Sci 340(1292):215–225], communication signals and perceptual systems have coevolved. A clear illustration of this is the evolution of the tetrapod middle ear, adapted to life on land. Here we report the discovery of a bone conduction–mediated stimulation of the ear by wave propagation in Sechellophryne gardineri, one of the world’s smallest terrestrial tetrapods, which lacks a middle ear yet produces acoustic signals. Based on X-ray synchrotron holotomography, we measured the biomechanical properties of the otic tissues and modeled the acoustic propagation. Our models show how bone conduction enhanced by the resonating role of the mouth allows these seemingly deaf frogs to communicate effectively without a middle ear. PMID:24003145

  5. Induction of photolyase activity in wood frog (Rana sylvatica) embryos.

    PubMed

    Smith, M A; Kapron, C M; Berrill, M

    2000-10-01

    Rising ultraviolet-B (UVB, 280-320 nm) radiation has been proposed as a factor which may explain nonnormal amphibian population declines. Accordingly research has been directed toward estimating the photolyase activity of several amphibian species in order to predict a species' resilience to UV damage. Unfortunately, in spite of published research which demonstrated that the activity of one of the principal photorepair enzymes, photolyase, can be induced, these estimates did not address the potential for in vivo induction by environmental factors present in situ. We show here that wood frog (Rana sylvatica) embryos exposed to periods of ambient solar radiation (1) displayed significantly different photolyase activities from embryos exposed to equivalent periods of dark; and (2) were positively correlated with the UVB fluence received in vivo. Such results suggest that previous conclusions regarding the relationship between photorepair and population decline must be reevaluated. Estimating amphibian photorepair is a complicated process, and caution must be exercised when interpreting such data. PMID:11045732

  6. Percutaneous absorption of chemicals: developing an understanding for the treatment of disease in frogs.

    PubMed

    Llewelyn, V K; Berger, L; Glass, B D

    2016-04-01

    The permeable nature of frog skin presents an alternative route for the delivery of therapeutic chemicals to treat disease in frogs. However, although therapeutic chemicals are often topically applied to the skin of frogs, their pharmacokinetics have rarely been reported. To provide evidence to guide both candidate drug and formulation selection, we highlight factors expected to influence percutaneous absorption through frog skin, including the anatomy and physiology of the skin and the physicochemical properties of applied therapeutic chemicals. Importantly, we also highlight the effects of the formulation on percutaneous absorption, especially the inclusion of potential penetration enhancers as excipients. Finally, we collate empirical data on the topical application of various therapeutic chemicals in postmetamorphic frogs and show that, in contrast to mammalian species, even large chemicals (i.e. >500 Da) and those with a wide range of log P values (-4 through +6) are likely to be absorbed percutaneously. Topical application in frogs thus promises a convenient and effective method for delivering systemic treatments of a diverse range of chemicals; however, further experimental quantification is required to ensure optimal outcomes. PMID:26456710

  7. California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

    USGS Publications Warehouse

    Fellers, G.M.; Kleeman, P.M.

    2007-01-01

    Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  8. Gas chromatographic and electron spin resonance investigations of gamma-irradiated frog legs

    NASA Astrophysics Data System (ADS)

    Morehouse, Kim M.; Ku, Yuoh; Albrecht, Heidi L.; George C., Yang

    Several very sensitive techniques to measure radiation-induced products in frog legs were investigated. Presented here are results from the use of electron spin resonance (ESR) spectroscopy and capillary gas chromatography (GC) to measure radiolysis products in γ-irradiated frog legs. When bone is irradiated, a characteristic ESR signal develops and is easily measured. The intensity of the ESR signal is dose-dependent and stable for several months at room temperature. When triglycerides or fatty acids are irradiated, some of the major stable products formed are hydrocarbons with one less carbon than the precursor fatty acids. These hydrocarbons are formed as the result of the loss of CO 2 during various free radical reactions. A capillary GC procedure was developed to monitor the formation of these hydrocarbons in γ-irradiated frog legs. Since frog legs contain large amounts of palmitic, stearic, oleic, and linoleic acids, the formation of the hydrocarbons (pentadecane, heptadecane, 8-heptadecene, and 6,9-heptadecadiene, respectively) from the decarboxylation of these fatty acids was monitored. The yields of these hydrocarbons were found to be linear with applied dose. A sample from a lot of imported frog legs that were believed to have been treated with ionizing radiation was also analyzed. The ESR technique, in conjunction with the GC data on the hydrocarbons, appears to be a useful approach for identifying and monitoring frog legs that have been treated with ionizing radiation.

  9. Frogs Jump Forward: Semantic Knowledge Influences the Perception of Element Motion in the Ternus Display.

    PubMed

    Hsu, Patty; Taylor, J Eric T; Pratt, Jay

    2015-01-01

    The Ternus effect is a robust illusion of motion that produces element motion at short interstimulus intervals (ISIs; < 50 ms) and group motion at longer ISIs (> 50 ms). Previous research has shown that the nature of the stimuli (e.g., similarity, grouping), not just ISI, can influence the likelihood of perceiving element or group motion. We examined if semantic knowledge can also influence what type of illusory motion is perceived. In Experiment I, we used a modified Ternus display with pictures of frogs in a jump-ready pose facing forwards or backwards to the direction of illusory motion. Participants perceived more element motion with the forward-facing frogs and more group motion with the backward-facing frogs. Experiment 2 tested whether this effect would still occur with line drawings of frogs, or if a more life-like image was necessary. Experiment 3 tested whether this effect was due to visual asymmetries inherent in the jumping pose. Experiment 4 tested whether frogs in a "non-jumping," sedentary pose would replicate the original effect. These experiments elucidate the role of semantic knowledge in the Ternus effect. Prior knowledge of the movement of certain animate objects, in this case, frogs can also bias the perception of element or group motion. PMID:26541055

  10. Towards a better understanding of the use of probiotics for preventing chytridiomycosis in Panamanian golden frogs.

    PubMed

    Becker, Matthew H; Harris, Reid N; Minbiole, Kevin P C; Schwantes, Christian R; Rollins-Smith, Louise A; Reinert, Laura K; Brucker, Robert M; Domangue, Rickie J; Gratwicke, Brian

    2011-12-01

    Populations of native Panamanian golden frogs (Atelopus zeteki) have collapsed due to a recent chytridiomycosis epidemic. Reintroduction efforts from captive assurance colonies are unlikely to be successful without the development of methods to control chytridiomycosis in the wild. In an effort to develop a protective treatment regimen, we treated golden frogs with Janthinobacterium lividum, a skin bacterium that has been used to experimentally prevent chytridiomycosis in North American amphibians. Although J. lividum appeared to colonize A. zeteki skin temporarily, it did not prevent or delay mortality in A. zeteki exposed to Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis. After introduction of J. lividum, average bacterial cell counts reached a peak of 1.7 × 10(6) cells per frog ~2 weeks after treatment but declined steadily after that. When J. lividum numbers declined to ~2.8 × 10(5) cells per frog, B. dendrobatidis infection intensity increased to greater than 13,000 zoospore equivalents per frog. At this point, frogs began to die of chytridiomycosis. Future research will concentrate on isolating and testing antifungal bacterial species from Panama that may be more compatible with Atelopus skin. PMID:22328095

  11. The pattern of catecholamine response to burst activity in leopard frogs, Rana pipiens.

    PubMed

    Fournier, P A; Nadeau, A; Guderley, H

    1994-07-01

    It is well known that burst activity causes a rapid breakdown of muscle glycogen and extensive accumulation of lactate in frogs. During recovery, it has been shown that lactate is nearly totally recycled into muscle glycogen. Since catecholamines are likely to play some role in the regulation of postexercise repletion of muscle glycogen, the pattern of catecholamine response was assessed in frogs during intense physical activity and the ensuing recovery period. Chronically cannulated frogs were forced to swim until exhaustion, and serial blood samples were taken at regular time intervals for the measurements of catecholamines. The pattern of changes in plasma and muscle lactate and glucose and muscle glycogen during and after burst activity is similar to that reported in previous studies using noncannulated frogs, a result which indicates that the animals recover well from the surgical trauma associated with cannulation. The concentrations of plasma catecholamines in frogs at rest are comparable to those measured in other amphibians, and the levels of plasma epinephrine in resting frogs are much higher than those of norepinephrine. Burst activity causes a marked increase in plasma catecholamines, with higher levels reached by epinephrine. During recovery, the concentration of plasma catecholamines returns to normal within 30 min. Although this pattern of catecholamine response to intense physical activity may be favorable to the repletion of muscle glycogen postexercise, it remains to be clarified how critical the low levels and fast reduction in plasma catecholamines are for optimum glycogen resynthesis. PMID:7926648

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

    PubMed

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

    1992-06-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1535482

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

    PubMed

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

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified. PMID:2458472

  14. Compartment calcium model of frog skeletal muscle during activation.

    PubMed

    Liu, Weifan; Olson, Sarah D

    2015-01-01

    Skeletal muscle contraction is triggered by a rise in calcium (Ca(2+)) concentration in the myofibrillar space. The objective of this study was to develop a voltage dependent compartment model of Ca(2+) dynamics in frog skeletal muscle fibers. The compartment model corresponds to the myofibrillar space (MS) and a calcium store, the sarcoplasmic reticulum (SR). Ca(2+) is released from the SR to the MS based on the voltage and is able to bind to several proteins in the MS. We use a detailed model to account for voltage dependent Ca(2+) release and inactivation. With this model, we are able to match previous experimental data for Ca(2+) release and binding to proteins for an applied (fixed) voltage. We explore the sensitivity of parameters in the model and illustrate the importance of inactivation of the SR; during a long depolarization, the SR must be inactivated in order to achieve realistic Ca(2+) concentrations in the MS. A Hodgkin Huxley type model was also developed to describe voltage at the surface membrane using electrophysiological data from previous experiments. This voltage model was then used as the time dependent voltage to determine Ca(2+) release from the SR. With this fully coupled model, we were able to match previous experimental results for Ca(2+) concentrations for a given applied current. Additionally, we examined simulated Ca(2+) concentrations in the case of twitch and tetanus, corresponding to different applied currents. The developed model is robust and reproduces many aspects of voltage dependent calcium signaling in frog skeletal muscle fibers. This modeling framework provides a platform for future studies of excitation contraction coupling in skeletal muscle fibers. PMID:25234233

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  16. Spatial diversity patterns of Pristimantis frogs in the Tropical Andes.

    PubMed

    Meza-Joya, Fabio Leonardo; Torres, Mauricio

    2016-04-01

    Although biodiversity gradients have been widely documented, the factors governing broad-scale patterns in species richness are still a source of intense debate and interest in ecology, evolution, and conservation biology. Here, we tested whether spatial hypotheses (species-area effect, topographic heterogeneity, mid-domain null model, and latitudinal effect) explain the pattern of diversity observed along the altitudinal gradient of Andean rain frogs of the genus Pristimantis. We compiled a gamma-diversity database of 378 species of Pristimantis from the tropical Andes, specifically from Colombia to Bolivia, using records collected above 500 m.a.s.l. Analyses were performed at three spatial levels: Tropical Andes as a whole, split in its two main domains (Northern and Central Andes), and split in its 11 main mountain ranges. Species richness, area, and topographic heterogeneity were calculated for each 500-m-width elevational band. Spatial hypotheses were tested using linear regression models. We examined the fit of the observed diversity to the mid-domain hypothesis using randomizations. The species richness of Pristimantis showed a hump-shaped pattern across most of the altitudinal gradients of the Tropical Andes. There was high variability in the relationship between area and species richness along the Tropical Andes. Correcting for area effects had little impact in the shape of the empirical pattern of biodiversity curves. Mid-domain models produced similar gradients in species richness relative to empirical gradients, but the fit varied among mountain ranges. The effect of topographic heterogeneity on species richness varied among mountain ranges. There was a significant negative relationship between latitude and species richness. Our findings suggest that spatial processes partially explain the richness patterns of Pristimantis frogs along the Tropical Andes. Explaining the current patterns of biodiversity in this hot spot may require further studies on

  17. Transport and distribution of sodium across frog skin

    PubMed Central

    Cereijido, M.; Rotunno, Catalina A.

    1967-01-01

    1. The time course of 22Na influx across frog skin mounted as a flat sheet between two lucite chambers has been studied. The flux reaches its maximal steady value in about 30 min. 2. The time course of changes in 22Na specific activity in the cells has been followed by two different methods: (1) periodical measurements of 22Na activity in pieces of skin mounted in a special device in which the outer facing membrane was in contact with the tracer and (2) measurement of uptake of 24Na in individual pieces of skin suspended in Ringer solution. Under both circumstances the skin failed to exchange all its Na. 3. Considerations on the basis of the kinetics of 22Na influx and 22Na specific activity indicate that there exist at least two different Na compartments in the epithelium, one of them being directly involved in Na transport. 4. The 22Na specific activity profile was studied in skins which had previously been mounted as a flat sheet between two chambers with tracer in one of them. This was carried out by removing the skin from the chamber, freezing, slicing and analysing the slices for Na and 22Na. The results indicate that both Na compartments are distributed across the whole epithelium. 5. The results of these studies are taken to indicate: (a) that the Na partition in the tissue is not a result of the Na being contained in different cellular layers; (b) that Na transport across frog skin is carried out by all the epithelial cells and is not restricted to those of a particular layer; (c) that Na entry from an outer solution containing from 1 to 10 mM-Na occurs into the transporting cells down an electrochemical potential gradient and therefore need not involve an active mechanism at the outer border of the cells. PMID:6051783

  18. Is Chytridiomycosis Driving Darwin’s Frogs to Extinction?

    PubMed Central

    Soto-Azat, Claudio; Valenzuela-Sánchez, Andrés; Clarke, Barry T.; Busse, Klaus; Ortiz, Juan Carlos; Barrientos, Carlos; Cunningham, Andrew A.

    2013-01-01

    Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd) infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9%) of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans), all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9%) was significantly lower than that found in other anurans (7.3%). The prevalence of infection (30%) in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x2 = 106.407, P<0.001). This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further. PMID:24278196

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

    PubMed

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

    2011-05-01

    Non-recombining sex chromosomes are expected to undergo evolutionary decay, ending up genetically degenerated, as has happened in birds and mammals. Why are then sex chromosomes so often homomorphic in cold-blooded vertebrates? One possible explanation is a high rate of turnover events, replacing master sex-determining genes by new ones on other chromosomes. An alternative is that X-Y similarity is maintained by occasional recombination events, occurring in sex-reversed XY females. Based on mitochondrial and nuclear gene sequences, we estimated the divergence times between European tree frogs (Hyla arborea, H. intermedia, and H. molleri) to the upper Miocene, about 5.4-7.1 million years ago. Sibship analyses of microsatellite polymorphisms revealed that all three species have the same pair of sex chromosomes, with complete absence of X-Y recombination in males. Despite this, sequences of sex-linked loci show no divergence between the X and Y chromosomes. In the phylogeny, the X and Y alleles cluster according to species, not in groups of gametologs. We conclude that sex-chromosome homomorphy in these tree frogs does not result from a recent turnover but is maintained over evolutionary timescales by occasional X-Y recombination. Seemingly young sex chromosomes may thus carry old-established sex-determining genes, a result at odds with the view that sex chromosomes necessarily decay until they are replaced. This raises intriguing perspectives regarding the evolutionary dynamics of sexually antagonistic genes and the mechanisms that control X-Y recombination. PMID:21629756

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

    SciTech Connect

    Monson, P.D.; Call, D.J.; Cox, D.A.; Liber, K.; Ankley, G.T.

    1999-02-01

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

  1. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    PubMed

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models. PMID:25593158

  2. Impact of global warming at the range margins: phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian

    PubMed Central

    Ruiz-Aravena, Manuel; Gonzalez-Mendez, Avia; Estay, Sergio A; Gaitán-Espitia, Juan D; Barria-Oyarzo, Ismael; Bartheld, José L; Bacigalupe, Leonardo D

    2014-01-01

    When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally. PMID:25512843

  3. Impact of global warming at the range margins: phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian.

    PubMed

    Ruiz-Aravena, Manuel; Gonzalez-Mendez, Avia; Estay, Sergio A; Gaitán-Espitia, Juan D; Barria-Oyarzo, Ismael; Bartheld, José L; Bacigalupe, Leonardo D

    2014-12-01

    When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally. PMID:25512843

  4. Spatial distribution of Madeira Island Laurisilva endemic spiders (Arachnida: Araneae)

    PubMed Central

    2014-01-01

    Abstract Madeira island presents a unique spider diversity with a high number of endemic species, many of which are still poorly known. A recent biodiversity survey on the terrestrial arthropods of the native forest, Laurisilva, provided a large set of standardized samples from various patches throughout the island. Out of the fifty two species recorded, approximately 33.3% are Madeiran endemics, many of which had not been collected since their original description. Two new species to science are reported – Ceratinopsis n. sp. and Theridion n. sp. – and the first records of Poeciloneta variegata (Blackwall, 1841) and Tetragnatha intermedia Kulczynski, 1891 are reported for the first time for Madeira island. Considerations on species richness and abundance from different Laurisilva locations are presented, together with distribution maps for endemic species. These results contribute to a better understanding of spider diversity patterns and endemic species distribution in the native forest of Madeira island. PMID:24855443

  5. Bird pollination of Canary Island endemic plants

    NASA Astrophysics Data System (ADS)

    Ollerton, Jeff; Cranmer, Louise; Stelzer, Ralph J.; Sullivan, Steve; Chittka, Lars

    2009-02-01

    The Canary Islands are home to a guild of endemic, threatened bird-pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently, they appear to have co-opted generalist passerine birds as sub-optimal pollinators. To test this idea, we carried out a quantitative study of the pollination biology of three of the bird-pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops as well as seed-set and pollen removal and deposition. These data showed that the plants are effectively pollinated by non-flower specialist passerine birds that only occasionally visit flowers. The large nectar standing crops and extended flower longevities (>10 days) of Canarina and Isoplexis suggests that they have evolved a bird pollination system that effectively exploits these low frequency non-specialist pollen vectors and is in no way sub-optimal. Seed set in two of the three species was high and was significantly reduced or zero in flowers where pollinator access was restricted. In L. berthelotii, however, no fruit set was observed, probably because the plants were self-incompatible horticultural clones of a single genet. We also show that, while all three species are easily detectable for birds, the orange Canarina and the red Lotus (but less so the yellow-orange Isoplexis) should be difficult to detect for insect pollinators without specialised red receptors, such as bumblebees. Contrary to expectations if we accept that the flowers are primarily adapted to sunbird pollination, the chiffchaff ( Phylloscopus canariensis) was an effective pollinator of these species.

  6. Biological model of diversification and the biogeography of endemism

    SciTech Connect

    Connor, E.F.; McKenney, M.S.

    1985-01-01

    Endemic taxa have restricted geographical distributions in some relative sense. This may arise via vicariant range fragmentation affecting entire biotas, or by dispersal and ecological specialization affecting individual species. Endemics arising because of vicariance will tend to show concordant, overlapping distributions, while endemics arising because of dispersal will be largely independently distributed. As a result, the extent to which a biota has experienced vicariant events should be manifest by geographical concentrations of endemic taxa. The evidence adduced in favor of this hypothesis is that the geographical distributions of endemic taxa are unusually concordant. The authors present a test of this hypothesis using the biogeographies of species and subspecies of birds distributed across the lowlands of northern South America. Their results indicate that the distributions of extant endemics is consistent with a major role for vicariant speciation within the Amazon basin. This approach to assessing the role of vicariance in speciation and biogeography is more robust than cladistic analyses because it is insensitive to variation in rates of evolution.

  7. Prediction of phylogeographic endemism in an environmentally complex biome

    PubMed Central

    Carnaval, Ana Carolina; Waltari, Eric; Rodrigues, Miguel T.; Rosauer, Dan; VanDerWal, Jeremy; Damasceno, Roberta; Prates, Ivan; Strangas, Maria; Spanos, Zoe; Rivera, Danielle; Pie, Marcio R.; Firkowski, Carina R.; Bornschein, Marcos R.; Ribeiro, Luiz F.; Moritz, Craig

    2014-01-01

    Phylogeographic endemism, the degree to which the history of recently evolved lineages is spatially restricted, reflects fundamental evolutionary processes such as cryptic divergence, adaptation and biological responses to environmental heterogeneity. Attempts to explain the extraordinary diversity of the tropics, which often includes deep phylogeographic structure, frequently invoke interactions of climate variability across space, time and topography. To evaluate historical versus contemporary drivers of phylogeographic endemism in a tropical system, we analyse the effects of current and past climatic variation on the genetic diversity of 25 vertebrates in the Brazilian Atlantic rainforest. We identify two divergent bioclimatic domains within the forest and high turnover around the Rio Doce. Independent modelling of these domains demonstrates that endemism patterns are subject to different climatic drivers. Past climate dynamics, specifically areas of relative stability, predict phylogeographic endemism in the north. Conversely, contemporary climatic heterogeneity better explains endemism in the south. These results accord with recent speleothem and fossil pollen studies, suggesting that climatic variability through the last 250 kyr impacted the northern and the southern forests differently. Incorporating sub-regional differences in climate dynamics will enhance our ability to understand those processes shaping high phylogeographic and species endemism, in the Neotropics and beyond. PMID:25122231

  8. Climate threat on the Macaronesian endemic bryophyte flora.

    PubMed

    Patiño, Jairo; Mateo, Rubén G; Zanatta, Florian; Marquet, Adrien; Aranda, Silvia C; Borges, Paulo A V; Dirkse, Gerard; Gabriel, Rosalina; Gonzalez-Mancebo, Juana M; Guisan, Antoine; Muñoz, Jesús; Sim-Sim, Manuela; Vanderpoorten, Alain

    2016-01-01

    Oceanic islands are of fundamental importance for the conservation of biodiversity because they exhibit high endemism rates coupled with fast extinction rates. Nowhere in Europe is this pattern more conspicuous than in the Macaronesian biogeographic region. A large network of protected areas within the region has been developed, but the question of whether these areas will still be climatically suitable for the globally threatened endemic element in the coming decades remains open. Here, we make predictions on the fate of the Macaronesian endemic bryophyte flora in the context of ongoing climate change. The potential distribution of 35 Macaronesian endemic bryophyte species was assessed under present and future climate conditions using an ensemble modelling approach. Projections of the models under different climate change scenarios predicted an average decrease of suitable areas of 62-87% per species and a significant elevational increase by 2070, so that even the commonest species were predicted to fit either the Vulnerable or Endangered IUCN categories. Complete extinctions were foreseen for six of the studied Macaronesian endemic species. Given the uncertainty regarding the capacity of endemic species to track areas of suitable climate within and outside the islands, active management associated to an effective monitoring program is suggested. PMID:27377592

  9. Climate threat on the Macaronesian endemic bryophyte flora

    PubMed Central

    Patiño, Jairo; Mateo, Rubén G.; Zanatta, Florian; Marquet, Adrien; Aranda, Silvia C.; Borges, Paulo A. V.; Dirkse, Gerard; Gabriel, Rosalina; Gonzalez-Mancebo, Juana M.; Guisan, Antoine; Muñoz, Jesús; Sim-Sim, Manuela; Vanderpoorten, Alain

    2016-01-01

    Oceanic islands are of fundamental importance for the conservation of biodiversity because they exhibit high endemism rates coupled with fast extinction rates. Nowhere in Europe is this pattern more conspicuous than in the Macaronesian biogeographic region. A large network of protected areas within the region has been developed, but the question of whether these areas will still be climatically suitable for the globally threatened endemic element in the coming decades remains open. Here, we make predictions on the fate of the Macaronesian endemic bryophyte flora in the context of ongoing climate change. The potential distribution of 35 Macaronesian endemic bryophyte species was assessed under present and future climate conditions using an ensemble modelling approach. Projections of the models under different climate change scenarios predicted an average decrease of suitable areas of 62–87% per species and a significant elevational increase by 2070, so that even the commonest species were predicted to fit either the Vulnerable or Endangered IUCN categories. Complete extinctions were foreseen for six of the studied Macaronesian endemic species. Given the uncertainty regarding the capacity of endemic species to track areas of suitable climate within and outside the islands, active management associated to an effective monitoring program is suggested. PMID:27377592

  10. Prediction of phylogeographic endemism in an environmentally complex biome.

    PubMed

    Carnaval, Ana Carolina; Waltari, Eric; Rodrigues, Miguel T; Rosauer, Dan; VanDerWal, Jeremy; Damasceno, Roberta; Prates, Ivan; Strangas, Maria; Spanos, Zoe; Rivera, Danielle; Pie, Marcio R; Firkowski, Carina R; Bornschein, Marcos R; Ribeiro, Luiz F; Moritz, Craig

    2014-10-01

    Phylogeographic endemism, the degree to which the history of recently evolved lineages is spatially restricted, reflects fundamental evolutionary processes such as cryptic divergence, adaptation and biological responses to environmental heterogeneity. Attempts to explain the extraordinary diversity of the tropics, which often includes deep phylogeographic structure, frequently invoke interactions of climate variability across space, time and topography. To evaluate historical versus contemporary drivers of phylogeographic endemism in a tropical system, we analyse the effects of current and past climatic variation on the genetic diversity of 25 vertebrates in the Brazilian Atlantic rainforest. We identify two divergent bioclimatic domains within the forest and high turnover around the Rio Doce. Independent modelling of these domains demonstrates that endemism patterns are subject to different climatic drivers. Past climate dynamics, specifically areas of relative stability, predict phylogeographic endemism in the north. Conversely, contemporary climatic heterogeneity better explains endemism in the south. These results accord with recent speleothem and fossil pollen studies, suggesting that climatic variability through the last 250 kyr impacted the northern and the southern forests differently. Incorporating sub-regional differences in climate dynamics will enhance our ability to understand those processes shaping high phylogeographic and species endemism, in the Neotropics and beyond. PMID:25122231

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

    PubMed Central

    Li, Yongmin; Wu, Xiaoyou; Zhang, Huabin; Yan, Peng; Xue, Hui; Wu, Xiaobing

    2015-01-01

    Paleogeological events and Pleistocene climatic fluctuations have had profound influences on the genetic patterns and phylogeographic structure of species in southern China. In this study, we investigated the population genetic structure and Phylogeography of the Odorrana schmackeri species complex, mountain stream-dwelling odorous frogs, endemic to southern China. We obtained mitochondrial sequences (1,151bp) of the complete ND2 gene and two flanking tRNAs of 511 individuals from 25 sites for phylogeographic analyses. Phylogenetic reconstruction revealed seven divergent evolutionary lineages, with mean pairwise (K2P) sequence distances from 7.8% to 21.1%, except for a closer ND2 distance (3.4%). The complex geological history of southern China drove matrilineal divergence in the O. schmackeri species complex into highly structured geographical units. The first divergence between lineage A+B and other lineages (C-G) had likely been influenced by the uplift of coastal mountains of Southeast China during the Mio-Pliocene period. The subsequent divergences between the lineages C-G may have followed the formation of the Three Gorges and the intensification of the East Asian summer monsoon during the late Pliocene and early Pleistocene. Demographic analyses indicated that major lineages A and C have been experienced recent population expansion (c. 0.045–0.245 Ma) from multiple refugia prior to the Last Glacial Maximum (LGM). Molecular analysis suggest that these seven lineages may represent seven different species, three described species and four cryptic species and should at least be separated into seven management units corresponding to these seven geographic lineages for conservation. PMID:26394403

  12. An Ancient Origin for the Enigmatic Flat-Headed Frogs (Bombinatoridae: Barbourula) from the Islands of Southeast Asia

    PubMed Central

    Blackburn, David C.; Bickford, David P.; Diesmos, Arvin C.; Iskandar, Djoko T.; Brown, Rafe M.

    2010-01-01

    Background The complex history of Southeast Asian islands has long been of interest to biogeographers. Dispersal and vicariance events in the Pleistocene have received the most attention, though recent studies suggest a potentially more ancient history to components of the terrestrial fauna. Among this fauna is the enigmatic archaeobatrachian frog genus Barbourula, which only occurs on the islands of Borneo and Palawan. We utilize this lineage to gain unique insight into the temporal history of lineage diversification in Southeast Asian islands. Methodology/Principal Findings Using mitochondrial and nuclear genetic data, multiple fossil calibration points, and likelihood and Bayesian methods, we estimate phylogenetic relationships and divergence times for Barbourula. We determine the sensitivity of focal divergence times to specific calibration points by jackknife approach in which each calibration point is excluded from analysis. We find that relevant divergence time estimates are robust to the exclusion of specific calibration points. Barbourula is recovered as a monophyletic lineage nested within a monophyletic Costata. Barbourula diverged from its sister taxon Bombina in the Paleogene and the two species of Barbourula diverged in the Late Miocene. Conclusions/Significance The divergences within Barbourula and between it and Bombina are surprisingly old and represent the oldest estimates for a cladogenetic event resulting in living taxa endemic to Southeast Asian islands. Moreover, these divergence time estimates are consistent with a new biogeographic scenario: the Palawan Ark Hypothesis. We suggest that components of Palawan's terrestrial fauna might have “rafted” on emergent portions of the North Palawan Block during its migration from the Asian mainland to its present-day position near Borneo. Further, dispersal from Palawan to Borneo (rather than Borneo to Palawan) may explain the current day disjunct distribution of this ancient lineage. PMID:20711504

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

    PubMed Central

    2013-01-01

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

  14. Ultraviolet Radiation Influences Perch Selection by a Neotropical Poison-Dart Frog

    PubMed Central

    Kats, Lee B.; Bucciarelli, Gary M.; Schlais, David E.; Blaustein, Andrew R.; Han, Barbara A.

    2012-01-01

    Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy. PMID:23251505

  15. Field hydration state varies among tropical frog species with different habitat use.

    PubMed

    Tracy, Christopher R; Tixier, Thomas; Le Nöene, Camille; Christian, Keith A

    2014-01-01

    We have previously shown that ecological habit (e.g., arboreal, terrestrial, amphibious) correlates with thermoregulatory behaviors and water balance physiology among species of hylid frogs in northern Australia. We hypothesized that these frogs would be different with respect to their field hydration states because of the challenges associated with the different ecological habits. There are very few data on the hydration levels that frogs maintain in the field, and the existing data are from disparate species and locations and do not relate hydration state to habit or changes in seasonal water availability. We measured the hydration state of 15 species of frogs from tropical northern Australia to determine the influences of ecological habit and season on the hydration state that these frogs maintain. As predicted, frogs were significantly less hydrated in the dry season than they were in the wet season and showed significantly higher variation among individuals, suggesting that maintaining hydration is more challenging in the dry season. In the wet season, terrestrial species were significantly less hydrated than arboreal or amphibious species. During the dry season, amphibious species that sought refuge in cracking mud after the pond dried were significantly less hydrated than terrestrial or arboreal species. These data suggest that hydration behaviors and voluntary tolerance of dehydration vary with habitat use, even within closely related species in the same family or genus. Terrestrial and arboreal species might be expected to be the most vulnerable to changes in water availability, because they are somewhat removed from water sources, but the physiological characteristics of arboreal frogs that result in significant cutaneous resistance to water loss allow them to reduce the effects of their dehydrating microenvironment. PMID:24642537

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

    PubMed

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

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

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

    PubMed

    Kats, Lee B; Bucciarelli, Gary M; Schlais, David E; Blaustein, Andrew R; Han, Barbara A

    2012-01-01

    Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy. PMID:23251505

  18. Cryoprotectants and Extreme Freeze Tolerance in a Subarctic Population of the Wood Frog

    PubMed Central

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

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to –8°C, either directly or following three cycles of freezing/thawing between –4 and 0°C, or –16°C increased the liver’s synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

  19. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    PubMed Central

    Netherlands, Edward C.; Cook, Courtney A.; Kruger, Donnavan J.D.; du Preez, Louis H.; Smit, Nico J.

    2015-01-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01) in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity. PMID:25830113

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

    PubMed

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

    2015-01-01

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

  1. Biomarkers of oxidative stress and metal accumulation in marsh frog (Pelophylax ridibundus).

    PubMed

    Borković-Mitić, Slavica S; Prokić, Marko D; Krizmanić, Imre I; Mutić, Jelena; Trifković, Jelena; Gavrić, Jelena; Despotović, Svetlana G; Gavrilović, Branka R; Radovanović, Tijana B; Pavlović, Slađan Z; Saičić, Zorica S

    2016-05-01

    To understand the effect of metals on the marsh frog Pelophylax ridibundus and the possible environment-induced changes in oxidative stress enzymes, we determined the concentrations of 18 metals: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, In, Li, Mn, Ni, Pb, Sr, and Zn, in the tissues (liver, skin, and muscle) and water samples collected from different locations in Serbia. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione S-transferase (GST), acetylcholinesterase (AChE), and changes in concentrations of reduced glutathione (GSH) and sulfhydryl groups (SH) were analyzed in the tissues of the sampled frogs. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Ga, Hg, and Ni were highest in the liver, whereas those of Ba, Ca, Li, Mn, Pb, Sr, and Zn were highest in the skin. Hg correlated positively with liver SOD (in frogs from Danube-Tisza-Danube Canal (DTD)), muscle CAT (DTD), and muscle GST Ponjavica River (PO); Pb demonstrated a strong positive correlation with liver GR in frogs from Mt. Fruška Gora (FG); Cd only exhibited a positive correlation with AChE in the skin of frogs from DTD. In the skin, Zn correlated positively with AChE (DTD), SH groups (PO), and CAT (FG), and negatively with CAT, GST, and SH in the liver of frogs from DTD. Examination of these oxidative stress biomarkers, together with analysis of metal accumulation in the liver and skin of marsh frogs, provides a powerful tool for the assessment of metal pollution. PMID:26846240

  2. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

    PubMed

    Netherlands, Edward C; Cook, Courtney A; Kruger, Donnavan J D; du Preez, Louis H; Smit, Nico J

    2015-04-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01) in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity. PMID:25830113

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

    PubMed Central

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

    2015-01-01

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

  4. Defects in Host Immune Function in Tree Frogs with Chronic Chytridiomycosis

    PubMed Central

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

    2014-01-01

    The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea) and white-lipped (L. infrafrenata) tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species. PMID:25211333

  5. Enzymatic Regulation of Glycogenolysis in a Subarctic Population of the Wood Frog: Implications for Extreme Freeze Tolerance

    PubMed Central

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

    2013-01-01

    The wood frog, Rana sylvatica, from Interior Alaska survives freezing at –16°C, a temperature 10–13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype’s exceptional freeze tolerance, which is necessary for their survival in a subarctic climate. PMID:24236105

  6. A World Malaria Map: Plasmodium falciparum Endemicity in 2007

    PubMed Central

    Hay, Simon I; Guerra, Carlos A; Gething, Peter W; Patil, Anand P; Tatem, Andrew J; Noor, Abdisalan M; Kabaria, Caroline W; Manh, Bui H; Elyazar, Iqbal R. F; Brooker, Simon; Smith, David L; Moyeed, Rana A; Snow, Robert W

    2009-01-01

    Background Efficient allocation of resources to intervene against malaria requires a detailed understanding of the contemporary spatial distribution of malaria risk. It is exactly 40 y since the last global map of malaria endemicity was published. This paper describes the generation of a new world map of Plasmodium falciparum malaria endemicity for the year 2007. Methods and Findings A total of 8,938 P. falciparum parasite rate (PfPR) surveys were identified using a variety of exhaustive search strategies. Of these, 7,953 passed strict data fidelity tests for inclusion into a global database of PfPR data, age-standardized to 2–10 y for endemicity mapping. A model-based geostatistical procedure was used to create a continuous surface of malaria endemicity within previously defined stable spatial limits of P. falciparum transmission. These procedures were implemented within a Bayesian statistical framework so that the uncertainty of these predictions could be evaluated robustly. The uncertainty was expressed as the probability of predicting correctly one of three endemicity classes; previously stratified to be an informative guide for malaria control. Population at risk estimates, adjusted for the transmission modifying effects of urbanization in Africa, were then derived with reference to human population surfaces in 2007. Of the 1.38 billion people at risk of stable P. falciparum malaria, 0.69 billion were found in Central and South East Asia (CSE Asia), 0.66 billion in Africa, Yemen, and Saudi Arabia (Africa+), and 0.04 billion in the Americas. All those exposed to stable risk in the Americas were in the lowest endemicity class (PfPR2−10 ≤ 5%). The vast majority (88%) of those living under stable risk in CSE Asia were also in this low endemicity class; a small remainder (11%) were in the intermediate endemicity class (PfPR2−10 > 5 to < 40%); and the remaining fraction (1%) in high endemicity (PfPR2−10 ≥ 40%) areas. High endemicity was widespread in the

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

    PubMed

    Westgate, Martin J; Scheele, Ben C; Ikin, Karen; Hoefer, Anke Maria; Beaty, R Matthew; Evans, Murray; Osborne, Will; Hunter, David; Rayner, Laura; Driscoll, Don A

    2015-01-01

    Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization) had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species. PMID:26580412

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

    PubMed

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

    2016-05-01

    Detour behaviour, an individual's ability to reach its goal by taking an indirect route, has been used to test spatial cognitive abilities across a variety of taxa. Although many amphibians show a strong homing ability, there is currently little evidence of amphibian spatial cognitive flexibility. We tested whether a territorial frog, Allobates femoralis, can flexibly adjust its homing path when faced with an obstacle. We displaced male frogs from their calling sites into the centre of circular arenas and recorded their escape routes. In the first experiment we provided an arena with equally high walls. In the second experiment we doubled the height of the homeward facing wall. Finally, we provided a tube as a shortcut through the high wall. In the equal-height arena, most frogs chose to escape via the quadrant facing their former calling site. However, when challenged with different heights, nearly all frogs chose the low wall, directing their movements away from the calling site. In the "escape tunnel" experiment most frogs still chose the low wall. Our results show that displaced A. femoralis males can flexibly adjust their homing path and avoid (presumably energetically costly) obstacles, providing experimental evidence of spatial cognitive flexibility in an amphibian. PMID:26997105

  9. Chemical Camouflage– A Frog's Strategy to Co-Exist with Aggressive Ants

    PubMed Central

    Rödel, Mark-Oliver; Brede, Christian; Hirschfeld, Mareike; Schmitt, Thomas; Favreau, Philippe; Stöcklin, Reto; Wunder, Cora; Mebs, Dietrich

    2013-01-01

    Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression. PMID:24349157

  10. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    PubMed

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. PMID:26033303

  11. Treatment trial of clinically ill corroboree frogs with chytridiomycosis with two triazole antifungals and electrolyte therapy.

    PubMed

    Brannelly, Laura A; Skerratt, Lee F; Berger, Lee

    2015-09-01

    Chytridiomycosis caused by the pathogen Batrachochytrium dendrobatidis is an important cause of amphibian declines globally, and is the worst pathogen on record for causing biodiversity loss. The critically endangered southern corroboree frog, Pseudophryne corroboree, is functionally extinct in the wild and is surviving in captive assurance colonies. These captive colonies must remain disease free, and there is no known treatment for corroboree frogs with terminal chytridiomycosis. In this study we tested two triazole antifungals (itraconazole and voriconazole) coupled with aggressive electrolyte therapy on moribund corroboree frogs with severe chytridiomycosis. Six moribund frogs were given 20 mL baths of 0.5 μg/mL itraconazole for 5 min/day for 5 days coupled with electrolyte injections every 8 h for 3 days followed by every 12 h for 3 days. Six other moribund frogs were given 1 mL drops of 1.25 μg/mL voriconazole daily for 7 days coupled with the aggressive electrolyte therapy. While only one animal survived this treatment regime, time until death was extended for all animals by at least 3 days and infection load decreased by an average of 89.3%. Our results suggest there is potential for recovery of terminally ill P. corroboree, and we suggest further trials include antibiotics as well as exploring variations on the above treatment regime with other antifungals. PMID:26246159

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

    PubMed

    Rödel, Mark-Oliver; Brede, Christian; Hirschfeld, Mareike; Schmitt, Thomas; Favreau, Philippe; Stöcklin, Reto; Wunder, Cora; Mebs, Dietrich

    2013-01-01

    Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression. PMID:24349157

  13. Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

    USGS Publications Warehouse

    Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

    2013-01-01

    The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

  14. Water balance and arginine vasotocin in the cocooning frog Cyclorana platycephala (hylidae).

    PubMed

    Cartledge, Victoria A; Withers, Philip C; Bradshaw, S Don

    2008-01-01

    It is well established that forming a cocoon, for frog species capable of doing so, markedly reduces evaporative water loss; however, the capacity of cocooned frogs to maintain hydration during extended estivation is not well understood. The combined effects of long-term estivation and water loss were examined in the cocoon-forming species Cyclorana platycephala by assessing the hydration state of the frogs throughout a 15-mo estivation period. Frogs lost mass throughout the 15-mo period to a maximum of 36%+/-6.5% of their initial standard mass. Plasma osmolality reached maximal levels by the ninth month of estivation at 487 mOsm kg(-1) and then remained stable to the fifteenth month of estivation. Urine osmolality continued to increase to the fifteenth month of estivation, at which point plasma and urine concentrations were isosmotic. The use of bladder water to counter losses from circulation was indicated by the relatively slow rate of increase in plasma osmolality with mass loss and the progressive increase in urine osmolality. For estivating frogs, evidence was found for a possible threshold relationship between plasma osmolality and plasma arginine vasotocin (AVT) concentration. After estivation, plasma AVT concentrations decreased markedly after 15-mo estivators were placed in water for 2 h, suggesting that high levels of AVT may not be integral to rapid rehydration in this species. PMID:18040971

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

    PubMed

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

    2007-11-01

    Physiological responses to dehydration in amphibians are reasonably well documented, although little work has addressed this problem in hibernating animals. We investigated osmotic and metabolic responses to experimental manipulation of hydration state in the wood frog (Rana sylvatica), a terrestrial hibernator that encounters low environmental water potential during autumn and winter. In winter-conditioned frogs, plasma osmolality varied inversely with body water content (range 69-79%, fresh mass) primarily due to increases in sodium and chloride concentrations, as well as accumulation of glucose and urea. Decreased hydration was accompanied by a marked reduction in the resting rate of oxygen consumption, which was inversely correlated with plasma osmolality and urea concentration. In a separate experiment, resting rates of oxygen consumption in fully hydrated frogs receiving injections of saline or saline containing urea did not differ initially; however, upon dehydration, metabolic rates decreased sooner in the urea-loaded frogs than in control frogs. Our findings suggest an important role for urea, acting in concert with dehydration, in the metabolic regulation and energy conservation of hibernating R. sylvatica. PMID:17661060

  16. Habitat fragmentation causes bottlenecks and inbreeding in the European tree frog (Hyla arborea).

    PubMed

    Andersen, Liselotte W; Fog, Kåre; Damgaard, Christian

    2004-06-22

    A genetic study of the European tree frog, Hyla arborea, in Denmark was undertaken to examine the population structure on mainland Jutland and the island of Lolland after a period of reduction in suitable habitat and population sizes. The two regions have experienced the same rate of habitat loss but fragmentation has been more severe on Lolland. Genetic variation based on 12 polymorphic DNA microsatellites was analysed in 494 tree frogs sampled from two ponds in Jutland and 10 ponds on Lolland. A significant overall deviation from Hardy-Weinberg expectations could be attributed to three ponds, all on Lolland. This was most probably caused by an inbreeding effect reducing fitness, which was supported by the observed significant negative correlation between larva survival and mean F(IS) value and mean individual inbreeding coefficient. A significant reduction in genetic variation (bottleneck) was detected in most of the ponds on Lolland. Population-structure analysis suggested the existence of at least 11 genetically different populations, corresponding to most of the sampled population units. The results indicated that the populations were unique genetic units and could be used to illustrate the migration pattern between newly established ponds arisen either by natural colonization of tree frogs or by artificial introduction. A high degree of pond fidelity in the tree frogs was suggested. A severe fragmentation process reducing population size and fitness within some of the populations probably caused the significant reduction in genetic variation of tree frog populations on Lolland. PMID:15306354

  17. Frog: a FRee Online druG 3D conformation generator.

    PubMed

    Leite, T Bohme; Gomes, D; Miteva, M A; Chomilier, J; Villoutreix, B O; Tufféry, P

    2007-07-01

    In silico screening methods based on the 3D structures of the ligands or of the proteins have become an essential tool to facilitate the drug discovery process. To achieve such process, the 3D structures of the small chemical compounds have to be generated. In addition, for ligand-based screening computations or hierarchical structure-based screening projects involving a rigid-body docking step, it is necessary to generate multi-conformer 3D models for each input ligand to increase the efficiency of the search. However, most academic or commercial compound collections are delivered in 1D SMILES (simplified molecular input line entry system) format or in 2D SDF (structure data file), highlighting the need for free 1D/2D to 3D structure generators. Frog is an on-line service aimed at generating 3D conformations for drug-like compounds starting from their 1D or 2D descriptions. Given the atomic constitution of the molecules and connectivity information, Frog can identify the different unambiguous isomers corresponding to each compound, and generate single or multiple low-to-medium energy 3D conformations, using an assembly process that does not presently consider ring flexibility. Tests show that Frog is able to generate bioactive conformations close to those observed in crystallographic complexes. Frog can be accessed at http://bioserv.rpbs.jussieu.fr/Frog.html. PMID:17485475

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

    PubMed Central

    Westgate, Martin J.; Scheele, Ben C.; Ikin, Karen; Hoefer, Anke Maria; Beaty, R. Matthew; Evans, Murray; Osborne, Will; Hunter, David; Rayner, Laura; Driscoll, Don A.

    2015-01-01

    Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization) had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species. PMID:26580412

  19. Polychlorinated biphenyls and chlorinated pesticides in southern Ontario, Canada, green frogs

    SciTech Connect

    Russell, R.W.; Gillan, K.A.; Haffner, G.D.

    1997-11-01

    Green frogs were collected from seven southern Ontario, Canada, locations and analyzed for chlorinated organic chemicals to establish the relative distribution of these chemicals at specific sites. At Hillman Marsh, a wildlife reserve in an agricultural area, green frogs accumulated significantly greater amount of highly chlorinated polychlorinated biphenyls (PCBs) than green frogs from all other collection sites. The source of PCBs is unknown. At Ancaster, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) accumulated in green frogs to a significantly greater extent than at all other sites. This was attributed to the presence of agriculture at Ancaster and the historic use of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in agriculture. Chemical concentrations measured in green frogs from all locations were considerably lower than reported levels in other species resulting in observable effects. Specific data relating chronic effects in amphibians to environmental exposure to DDE and PCBs is lacking. Contaminant accumulation in southern Ontario amphibians may be an important factor contributing to amphibian declines only at specific sites.

  20. Inflammation-Induced Reactivation of the Ranavirus Frog Virus 3 in Asymptomatic Xenopus laevis

    PubMed Central

    Robert, Jacques; Grayfer, Leon; Edholm, Eva-Stina; Ward, Brian; De Jesús Andino, Francisco

    2014-01-01

    Natural infections of ectothermic vertebrates by ranaviruses (RV, family Iridoviridae) are rapidly increasing, with an alarming expansion of RV tropism and resulting die-offs of numerous animal populations. Notably, infection studies of the amphibian Xenopus laevis with the ranavirus Frog Virus 3 (FV3) have revealed that although the adult frog immune system is efficient at controlling RV infections, residual quiescent virus can be detected in mononuclear phagocytes of otherwise asymptomatic animals following the resolution of RV infections. It is noteworthy that macrophage-lineage cells are now believed to be a critical element in the RV infection strategy. In the present work, we report that inflammation induced by peritoneal injection of heat-killed bacteria in asymptomatic frogs one month after infection with FV3 resulted in viral reactivation including detectable viral DNA and viral gene expression in otherwise asymptomatic frogs. FV3 reactivation was most prominently detected in kidneys and in peritoneal HAM56+ mononuclear phagocytes. Notably, unlike adult frogs that typically clear primary FV3 infections, a proportion of the animals succumbed to the reactivated FV3 infection, indicating that previous exposure does not provide protection against subsequent reactivation in these animals. PMID:25390636

  1. Lead concentrations in bullfrog Rana catesbeiana and green frog R. clamitans tadpoles inhabiting highway drainages

    USGS Publications Warehouse

    Birdsall, C.W.; Grue, C.E.; Anderson, A.

    1986-01-01

    Lead concentrations were determined in sediment and tadpoles of bullfrogs Rana catesbeiana and green frogs R. clamitans from drainages along highways with different daily average traffic volumes (range, 4272 to I08,800 vehicles day-I) and from ponds >0.4 km from the nearest highway. Lead concentrations (mg kg--I dry weight) in sediment (7-8 to 940) were usually greater (4-5 times) than those in the tadpoles (bullfrog, 0,07 to 270; green frog, 0,90 to 240 mg kg-I). Lead concentrations in sediment (r =0.63) and in both species of tadpoles (bullfrog, r = 0.69; green frog, r = 0.57) were positively correlated with average daily traffic volume. Lead concentrations in both species of tadpoles (bullfrog, r = (). 76: green frog, r = 0.75) were also positively correlated with lead concentrations in sediment. At sites where both bullfrog and green frog tadpoles were collected. lead concentrations in the two species were closely related (r = 0.84). Lead concentrations in tadpoles living near highways may contribute to the elevated lead levels reported in wildlife that are potential tadpole predators. Dietary lead concentrations similar to those in our tadpoles have been associated with physiological and reproductive effects in some species of birds and mammals. However, additional data are needed to determine the hazards to predators of lead concentrations in tadpoles.

  2. DNA repair and resistance to UV-B radiation in western spotted frogs

    USGS Publications Warehouse

    Blaustein, A.R.; Hays, J.B.; Hoffman, P.D.; Chivers, D.P.; Kiesecker, J.M.; Leonard, W.P.; Marco, A.; Olson, D.H.; Reaser, J.K.; Anthony, R.G.

    1999-01-01

    We assessed DNA repair and resistance to solar radiation in eggs of members of the western spotted frog complex (Rana pretiosa and R. luteiventris), species whose populations are suffering severe range reductions and declines. Specifically, we measured the activity of photoreactivating enzyme (photolyase) in oocytes of spotted frogs. In some species, photoreactivation is the most important mechanism for repair of UV-damaged DNA. Using field experiments, we also compared the hatching success of spotted frog embryos at natural oviposition sites at three elevations, where some embryos were subjected to ambient levels of UV-B radiation and others were shielded from UV-B radiation. Compared with other amphibians, photolyase activities in spotted frogs were relatively high. At all sites, hatching success was unaffected by UV-B. Our data support the interpretation that amphibian embryos with relatively high levels of photolyase are more resistant to UV-B radiation than those with lower levels of photolyase. At the embryonic stage, UV-B radiation does not presently seem to be contributing to the population declines of spotted frogs.

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

    USGS Publications Warehouse

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

    2000-01-01

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

  4. Diet of introduced bullfrogs (Rana catesbeiana): Predation on and diet overlap with native frogs on Daishan Island, China

    USGS Publications Warehouse

    Wu, Zhengjun; Li, Y.; Wang, Y.; Adams, Michael J.

    2005-01-01

    We examined diet of introduced Bullfrogs (Rana catesbeiana) and three native frog species (Rana limnocharis, Rana nigromaculata, and Bufo bufo gargarizans) co-occurring at a group of ponds on Daishan Island, east of China, to gain insight into the nature of potential interactions between Bullfrogs and native frog species. For postmetamorphic Bullfrogs, aquatic prey items dominated volumetrically. Prey size, diet volume and volumetric percentage of native frogs in diet increased with Bullfrog body size. The number and volumetric percentage of native frogs in the diet were not different for female and male Bullfrogs, and both were higher for adults than for juveniles. Diet overlap between males and juveniles was higher than that between males and females and between females and juveniles. Diet overlap with each native frog species of male Bullfrogs was lower than that of female Bullfrogs and juvenile Bullfrogs. We did not exam effects of Bullfrogs on native frogs but our results suggest that the primary threat posed by juvenile Bullfrogs to native frogs on Daishan Island is competition for food, whereas the primary threat posed by male Bullfrogs is direct predation. Female Bullfrogs may threaten native frogs by both competition and predation. These differences among Bullfrog groups may be attributed to differences in body size and microhabitat use.

  5. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Service's Safe Harbor Policy published in the Federal Register on June 17, 1999 (64 FR 32717), the Service... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow... the Federally threatened California red-legged frog (Rana draytonii), under the Endangered Species...

  6. Inverse Effects on Growth and Development Rates by Means of Endocrine Disruptors in African Clawed Frog Tadpoles ("Xenopus Laevis")

    ERIC Educational Resources Information Center

    Hackney, Zachary Carl

    2007-01-01

    Previous work on fish, frogs, and salamanders, showed the ability for estrogen (EE2) and anthropogenic endocrine disruptors to skew sex ratios and cause hermaphrodism. This study addressed the effects of estrogens on growth and development rates of African clawed frog tadpoles ("Xenopus laevis") during their gender determination stages. The…

  7. Extraordinary micro-endemism in Australian desert spring amphipods.

    PubMed

    Murphy, N P; Adams, M; Guzik, M T; Austin, A D

    2013-03-01

    Increasing pressure for water in the Australian arid zone is placing enormous stress on the diverse endemic communities inhabiting desert springs. Detailed information about the evolutionary processes occurring within and between individual endemic species will help to develop effective and biologically relevant management strategies this fragile ecosystem. To help determine conservation priorities, we documented the genetic structure of the endemic freshwater amphipod populations in springs fed by the Great Artesian Basin in central Australia. Phylogenetic and phylogeographic history and genetic diversity measures were examined using nuclear and mitochondrial DNA from approximately 500 chiltoniid amphipods across an entire group of springs. Pronounced genetic diversity was identified, demonstrating that levels of endemism have been grossly underestimated in these amphipods. Using the GMYC model, 13 genetically divergent lineages were recognized as Evolutionarily Significant Units (ESUs), all of which could be considered as separate species. The results show that due to the highly fragmented ecosystem, these taxa have highly restricted distributions. Many of the identified ESUs are endemic to a very small number of already degraded springs, with the rarest existing in single springs. Despite their extraordinarily small ranges, most ESUs showed relative demographic stability and high levels of genetic diversity, and genetic diversity was not directly linked to habitat extent. The relatively robust genetic health of ESUs does not preclude them from endangerment, as their limited distributions ensure they will be highly vulnerable to future water extraction. PMID:23142695

  8. Changing trends of an endemic trauma.

    PubMed

    Ahuja, Rajeev B; Bhattacharya, Sameek; Rai, Ashish

    2009-08-01

    The incidence of severe burn is extremely high in the Low and Middle Income Countries with an estimated 90% of the world incidence of which 50% is in South East Asia. Through an earlier analysis of 11,196 burn admission over 8 years (1993-2000--Phase I) to our burn unit we established the endemic nature of the injury [Ahuja RB, Bhattacharya S. An analysis of 11,196 burn admissions and evaluation of conservative management techniques. Burns 2002;28:555-61]. A continued analysis of 5566 burn admissions over the next 7 years (2001-2007--Phase II) and its comparison with the Phase I reveals a significant change in the epidemiological profile. The average yearly admissions have fallen by 43.14%, from 1399.5 patients in Phase I to 795.14 patients in Phase II. This fall in average yearly admissions is predominant in the age group 16-35 years (52.61% decline) and 36-55 years (46.51% decline). The overall female to male ratio has also changed from 1.26:1 to 0.91:1. However, the overall mean %TBSA burn has reduced only mildly from 49.12% TBSA in Phase I to 44.39% in Phase II. During Phase II there was also a significant decline of 46.93% and 56.25% in the yearly admission of flame and scald burn respectively. Non-intentional incidents still remain the main mode of injury accounting for 87.12% in Phase I and 89.89% in Phase II. But, the yearly admissions of non-intentional burns fell from 1219.25 in Phase I to 714.71 in Phase II, which is a significant drop of 41.38%. Kitchen continues to dominate as the main location for flame incidents, but the yearly admission rate from kitchen accidents dropped from 897.5 patients in Phase I to 368.43 patients in Phase II. At the same time, liquefied petroleum gas (LPG) leaks which accounted for only 0.72% of all kitchen accidents in Phase I rose to 10.74% in Phase II. Another redeeming feature is the reduction in overall mortality from 51.8% in Phase I to 40.20% in Phase II. Interestingly, a very significant negative correlation exists

  9. Heat production by single fibres of frog muscle.

    PubMed

    Curtin, N A; Howarth, J V; Woledge, R C

    1983-04-01

    The heat produced during contractions of preparations consisting of one or a few muscle fibres was measured for the first time. Fibres were dissected from the anterior tibialis muscles of the frog, Rana temporaria. Measurements were made with thermopiles of a design based on that described by Howarth et al. (1975). Although the fibre preparations were small, measurable signals could be recorded because the heat capacity of the thermopiles was also small. The output of the thermopile was amplified by a galvanometer circuit. In all the experiments the ends of the preparation were held in a fixed position during stimulation ("isometric'). Observations were made of heat production during twitches and tetanic contractions. The heat produced in a twitch of a single fibre depended on the stimulus strength in an all-or-nothing way. The results show that the amount of heat produced in individual twitches is fairly constant at different temperatures in the range 3-15 degrees C. In contrast, the heat produced in tetanic contractions is considerably greater at higher temperatures. The time course of heat production in a tetanus was influenced by temperature such that the early rapid phase of heat production was less obvious at the higher temperature. The quantities of heat produced by fibre preparations were in reasonable agreement with those produced by whole muscles when the comparison was made on the basis of heat produced per g wet weight of tissue. PMID:6602811

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

    PubMed

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

    2012-09-01

    Painted frogs (Discoglossus) are an anuran clade that originated in the Upper Miocene. Extant species are morphologically similar and have a circum-Mediterranean distribution. We assembled a multilocus dataset from seven nuclear and four mitochondrial genes for several individuals of all but one of the extant species and reconstructed a robust phylogeny by applying a coalescent-based species-tree method and a concatenation approach, both of which gave congruent results. The earliest phylogenetic split within Discoglossus separates D. montalentii from a clade comprising all other species. Discoglossus montalentii is monophyletic for haplotype variation at all loci and has distinct morphological, bioacoustic and karyotypic characters. We find moderate support for a sister-group relationship between the Iberian taxa and the Moroccan D. scovazzi, and high support for a D. pictus -D. sardus clade distributed around the Tyrrhenian basin. Topological discordance among gene trees during the speciation of D. galganoi, D. scovazzi, D. pictus and D. sardus is interpreted as the consequence of nearly simultaneous, vicariant diversification. The timing of these events is unclear, but possibly coincided with the final geotectonic rearrangement of the Western Mediterranean in the Middle Miocene or later during the Messinian salinity crisis. The Iberian taxa D. galganoi galganoi and D. g. jeanneae are reciprocally monophyletic in mitochondrial DNA but not in nuclear gene trees, and are therefore treated as subspecies of D. galganoi. PMID:22641173

  11. The importance of heterozygosity in a frog's life

    NASA Astrophysics Data System (ADS)

    Schmeller, Dirk S.; Schregel, Julia; Veith, Michael

    2007-05-01

    High genetic variability may increase metabolic efficiency and thus allows responding to environmental challenges as limits to adaptation are approached. Therefore, it has been suggested that high genetic variability contributes strongly to the fitness of an individual. Survival to high age may thus depend on high genetic variability, and genetically variable individuals may have a higher survival rate to high ages in comparison to less variable sympatric conspecifics. Such a heterozygosity × age relationship might be more readily detectable in stressful as compared to benign environments. For testing the relationship between age and heterozygosity, we genetically analyzed 71 individuals of the frog species Rana perezi from a total of seven populations at 13 allozyme loci. The age of the individuals was determined by skeletochronology. We found effects on age of both environment and allozyme heterozygosity, especially in populations with high stress regimes. A significant heterozygosity × age relationship has so far rarely been shown in natural populations. The result of our analysis suggests that more heterozygous individuals have a higher longevity and may be an important source of genetic variability of a population, likely contributing to a stabilization of the effective population size.

  12. Water Diffusion, T2, and Compartmentation in Frog Sciatic Nerve

    PubMed Central

    Peled, Sharon; Cory, David G.; Raymond, Stephen A.; Kirschner, Daniel A.; Jolesz, Ferenc A.

    2010-01-01

    A potential relationship between structural compartments in neural tissue and NMR parameters may increase the specificity of MRI in diagnosing diseases. Nevertheless, our understanding of MR of nerves and white matter is limited, particularly the influence of various water compartments on the MR signal is not known. In this study, components of the 1H transverse relaxation decay curve in frog peripheral nerve were correlated with the diffusion characteristics of the water in the nerve. Three T2 values were identified with nerve. Water mobility was found to be unrestricted on the timescale of 100 msec in the component of the signal with the intermediate T2 time, suggesting some contribution from the interstitial space to this T2 component. Restricted diffusion was observed in the component with the longest T2 time, supporting the assignment of at least part of the spins contributing to this component to an intracellular compartment. The observed nonexponential behavior of the diffusion attenuation curves was investigated and shown to be potentially caused by the wide range of axon sizes in the nerve. PMID:10542350

  13. Role of cutaneous surface fluid in frog osmoregulation.

    PubMed

    Larsen, Erik Hviid; Ramløv, Hans

    2013-07-01

    The study investigated whether evaporative water loss (EWL) in frogs stems from water diffusing through the skin or fluid secreted by mucous glands. Osmolality of cutaneous surface fluid (CSF) of Rana esculenta (Pelophylax kl. esculentus) subjected to isoproterenol or 30°C-34°C was 191±9.3 and 181±7.5 mosm/kg, respectively, as compared to lymph osmolality of, 249±10 mosm/kg. Cation concentrations of CSF were likewise independent of pre-treatment with averages of, [Na(+)]=65.5±5.1 and [K(+)]=14.9±1.6 mmol/L, and lymph concentrations of 116 mmol Na(+)/L and 5.1 mmol K(+)/L. The relatively high [K(+)] confirms that CSF is produced by submucosal glands. Since the chemical energy of water of CSF was always higher than that of body fluids, diffusion of water would be from CSF to the interstitial fluid and not in the opposite direction. It is concluded that volume and composition of CSF are regulated by subepidermal exocrine gland secretion balanced by EWL into the atmosphere and ion reuptake by the epidermal epithelium. Previously discovered regulatory mechanisms of epithelial ion absorption, hitherto not ascribed a body function, fit well with a role in regulating turnover of CSF. As a regulated external physiological compartment, CSF would be of importance for the immune defenses that amphibians employ in protecting their skin. PMID:23587876

  14. The adrenergic receptor subtypes present in frog (Rana esculenta) skin.

    PubMed

    Bellantuono, Vito; Cassano, Giuseppe; Lippe, Claudio

    2008-08-01

    Frog skin transports ions and water under hormonal control. In spite of the fundamental role played by adrenergic stimulation in maintaining the water balance of the organism, the receptor subtype(s) present in the skin have not been identified yet. We measured the increase in short-circuit current (ISC, an estimate of ion transport) induced by cirazoline, clonidine, xamoterol, formoterol, or BRL 37344, in order to verify the presence of alpha1, alpha2, beta1, beta2, or beta3 receptor subtypes, respectively. Only after treatment with formoterol, BRL 37344 and, to a lesser extent, cirazoline was measured a significant increase in ISC (57%, 33.2%, and 4.7%, respectively). The formoterol and BRL 37344 concentrations producing half-maximal effect (EC50) were 1.12 and 70.1 nM, respectively. Moreover, the formoterol effect was inhibited by treatment with ICI 118551 (antagonist of beta2 receptors) while SR 59230A (antagonist of beta3 receptors) had no effect; opposite findings were obtained when the BRL 37344 stimulation was investigated. Finally, by measuring the transepithelial fluxes of 22Na+ and 36Cl-, we demonstrated that Na+ absorption is increased by activation of beta2 and beta3 and is cAMP-sensitive, whereas the Cl- secretion is only increased by activation of beta2 receptors and is cAMP- and calmodulin-sensitive. PMID:18544474

  15. Sexual selection drives speciation in an Amazonian frog

    USGS Publications Warehouse

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

    2007-01-01

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

  16. Aposematism increases acoustic diversification and speciation in poison frogs.

    PubMed

    Santos, Juan C; Baquero, Margarita; Barrio-Amorós, César; Coloma, Luis A; Erdtmann, Luciana K; Lima, Albertina P; Cannatella, David C

    2014-12-01

    Multimodal signals facilitate communication with conspecifics during courtship, but they can also alert eavesdropper predators. Hence, signallers face two pressures: enticing partners to mate and avoiding detection by enemies. Undefended organisms with limited escape abilities are expected to minimize predator recognition over mate attraction by limiting or modifying their signalling. Alternatively, organisms with anti-predator mechanisms such as aposematism (i.e. unprofitability signalled by warning cues) might elaborate mating signals as a consequence of reduced predation. We hypothesize that calls diversified in association with aposematism. To test this, we assembled a large acoustic signal database for a diurnal lineage of aposematic and cryptic/non-defended taxa, the poison frogs. First, we showed that aposematic and non-aposematic species share similar extinction rates, and aposematic lineages diversify more and rarely revert to the non-aposematic phenotype. We then characterized mating calls based on morphological (spectral), behavioural/physiological (temporal) and environmental traits. Of these, only spectral and temporal features were associated with aposematism. We propose that with the evolution of anti-predator defences, reduced predation facilitated the diversification of vocal signals, which then became elaborated or showy via sexual selection. PMID:25320164

  17. Genetic diversification, vicariance, and selection in a polytypic frog.

    PubMed

    Robertson, Jeanne M; Zamudio, Kelly R

    2009-01-01

    Spatial patterns of heritable phenotypic diversity reflect the relative roles of gene flow and selection in determining geographic variation within a species. We quantified color differentiation and genetic divergence among 20 populations of the red-eyed tree frog (Agalychnis callidryas) in lower Central America. Phylogenetic analyses revealed 5 well-supported mitochondrial DNA clades, and we infer from our phylogeny that geographic barriers have played a large role in structuring populations. Two phenotypic characters varied independently among isolated population groups: Flank coloration distinguished Caribbean from Pacific individuals, whereas leg coloration exhibited a more complex geographic pattern. We detected 3 generalized spatial patterns of genetic and phenotypic diversity: 1) phenotypic differentiation in the presence of historical connectivity, 2) phenotypic uniformity across genetically differentiated regions, and 3) codistribution of genetic and phenotypic characters. These patterns indicate that phenotypic diversification is highly regionalized and can result from spatial variation in localized adaptations, geographic isolation, genetic drift, and/or evolutionary stasis. Although the mode of selection underlying color variation was not the focal objective of this study, we discuss the possible roles of natural and sexual selection in mediating population differentiation. Our study underscores the fact that selection gradients vary across relatively small spatial scales, even in species that occupy relatively homogeneous environments. PMID:19589848

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

    PubMed

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

    2016-04-01

    Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution. PMID:26960074

  19. Antibody dependent enhancement of frog virus 3 infection

    PubMed Central

    2010-01-01

    Background Viruses included in the family Iridoviridae are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3) is the type species of the genus Ranavirus and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it. Results Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement. Conclusions This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent. PMID:20167100

  20. Aposematism increases acoustic diversification and speciation in poison frogs

    PubMed Central

    Santos, Juan C.; Baquero, Margarita; Barrio-Amorós, César; Coloma, Luis A.; Erdtmann, Luciana K.; Lima, Albertina P.; Cannatella, David C.

    2014-01-01

    Multimodal signals facilitate communication with conspecifics during courtship, but they can also alert eavesdropper predators. Hence, signallers face two pressures: enticing partners to mate and avoiding detection by enemies. Undefended organisms with limited escape abilities are expected to minimize predator recognition over mate attraction by limiting or modifying their signalling. Alternatively, organisms with anti-predator mechanisms such as aposematism (i.e. unprofitability signalled by warning cues) might elaborate mating signals as a consequence of reduced predation. We hypothesize that calls diversified in association with aposematism. To test this, we assembled a large acoustic signal database for a diurnal lineage of aposematic and cryptic/non-defended taxa, the poison frogs. First, we showed that aposematic and non-aposematic species share similar extinction rates, and aposematic lineages diversify more and rarely revert to the non-aposematic phenotype. We then characterized mating calls based on morphological (spectral), behavioural/physiological (temporal) and environmental traits. Of these, only spectral and temporal features were associated with aposematism. We propose that with the evolution of anti-predator defences, reduced predation facilitated the diversification of vocal signals, which then became elaborated or showy via sexual selection. PMID:25320164

  1. [Current epidemiology and laboratory diagnosis of endemic mycoses in Spain].

    PubMed

    Buitrago, María J; Cuenca-Estrella, Manuel

    2012-08-01

    Histoplasmosis and paracoccidioidomycosis are emerging infections in Spain associated with immigration and travelling. In last three decades a total of 128 cases of histoplasmosis have been reported in Spain, 59 in travellers, 63 in immigrants, three associated to drug abuse, two in laboratory workers, and one in a solid organ transplant receptor. In 1969 the first Spanish case of paracoccidioidomycosis was published and a total of 21 cases have been reported so far. Those patients suffered from the chronic form of the disease with period of latency as long as 50 years. Other endemic mycoses such as blastomycosis, coccidioidomycosis, lobomycosis, pythiosis and sporotrichosis have not increased in frequency. Microbiological cultures of endemic fungi must be handled in facilities which comply with international biosafety regulations and must also be taken into account for cultures from patients with suspected endemic mycosis. PMID:22130575

  2. Possible differences in pathogenicity between cane toad-, frog- and platypus-derived isolates of Mucor amphibiorum, and a platypus-derived isolate of Mucor circinelloides.

    PubMed

    Stewart, N J; Munday, B L

    2005-03-01

    Platypuses (Ornithorhynchus anatinus) in the north of the island state of Tasmania, Australia, suffer from a serious disease called ulcerative mycosis, which is responsible for high morbidity and, presumably, mortality rates in areas where it occurs. The disease is caused by the dimorphic fungus Mucor amphibiorum, which is also found in Queensland, New South Wales and Victoria. However, it does not cause disease in platypuses in those states. It has been previously reported that a closely related fungus, Mucor circinelloides, may also be capable of causing this disease. This paper describes pathogenicity trials involving cane toads (Bufo marinus) as the experimental model. The toads were infected with either Tasmanian, platypus-derived M. amphibiorum, West Australian, frog-derived M. amphibiorum, Queensland cane-toad-derived M. amphibiorum or Tasmanian platypus-derived M. circinelloides. The Tasmanian isolates of M. amphibiorum were more likely to cause a serious, long-term infection than were Queensland or West Australian isolates, and (+) mating types caused a more serious infection than the (-) mating type. The isolate of M. circinelloides was incapable of infecting the toads, lending further weight to the theory that it represents an environmental contaminant. The results suggest that an endemic strain of M. amphibiorum has mutated and become pathogenic to platypuses. Alternatively, a pathogenic strain of M. amphibiorum may have been introduced into Tasmania, where it is infecting a naïve population. PMID:15832556

  3. Two new species of frogs of the genus Pristimantis from Llanganates National Park in Ecuador with comments on the regional diversity of Ecuadorian Pristimantis (Anura, Craugastoridae)

    PubMed Central

    Navarrete, María J.; Venegas, Pablo J.; Ron, Santiago R.

    2016-01-01

    Abstract We describe two new species of frogs of the genus Pristimantis from the eastern slopes of the Ecuadorian Andes, at Parque Nacional Llanganates. The new species are characterized by the spiny appearance typical of several species inhabiting montane forests. Pristimantis yanezi sp. n. is most similar to Pristimantis colonensis and Pristimantis incanus but differs from both in groin coloration and by having smaller tubercles on the upper eyelids, heels, and tarsus. Pristimantis llanganati sp. n. is most similar to Pristimantis eriphus and Pristimantis chloronotus. It can be distinguished from Pristimantis eriphus by the color pattern on the scapular region and by having smaller conical tubercles on the dorsum. Pristimantis chloronotus differs from Pristimantis llanganati sp. n. in having a pair of sinuous paravertebral folds. Both new species occur in a region with few amphibian collections and nothing is known about their abundance and ecology. Therefore, it is recommended to assign them to the Data Deficient Red List category. Updated figures of species richness of Pristimantis among biogeographic regions in Ecuador are also presented. Pristimantis reach their highest diversity in Montane Forests of the eastern versant of the Andes. Its species richness across regions cannot be explained by regional area, elevation, temperature, or precipitation. Political endemism in Pristimantis is higher than that of other terrestrial vertebrates. PMID:27408555

  4. Two new species of frogs of the genus Pristimantis from Llanganates National Park in Ecuador with comments on the regional diversity of Ecuadorian Pristimantis (Anura, Craugastoridae).

    PubMed

    Navarrete, María J; Venegas, Pablo J; Ron, Santiago R

    2016-01-01

    We describe two new species of frogs of the genus Pristimantis from the eastern slopes of the Ecuadorian Andes, at Parque Nacional Llanganates. The new species are characterized by the spiny appearance typical of several species inhabiting montane forests. Pristimantis yanezi sp. n. is most similar to Pristimantis colonensis and Pristimantis incanus but differs from both in groin coloration and by having smaller tubercles on the upper eyelids, heels, and tarsus. Pristimantis llanganati sp. n. is most similar to Pristimantis eriphus and Pristimantis chloronotus. It can be distinguished from Pristimantis eriphus by the color pattern on the scapular region and by having smaller conical tubercles on the dorsum. Pristimantis chloronotus differs from Pristimantis llanganati sp. n. in having a pair of sinuous paravertebral folds. Both new species occur in a region with few amphibian collections and nothing is known about their abundance and ecology. Therefore, it is recommended to assign them to the Data Deficient Red List category. Updated figures of species richness of Pristimantis among biogeographic regions in Ecuador are also presented. Pristimantis reach their highest diversity in Montane Forests of the eastern versant of the Andes. Its species richness across regions cannot be explained by regional area, elevation, temperature, or precipitation. Political endemism in Pristimantis is higher than that of other terrestrial vertebrates. PMID:27408555

  5. Co-Occurrence Patterns of Common and Rare Leaf-Litter Frogs, Epiphytic Ferns and Dung Beetles across a Gradient of Human Disturbance

    PubMed Central

    Oldekop, Johan A.; Bebbington, Anthony J.; Truelove, Nathan K.; Tysklind, Niklas; Villamarín, Santiago; Preziosi, Richard F.

    2012-01-01

    Indicator taxa are commonly used to identify priority areas for conservation or to measure biological responses to environmental change. Despite their widespread use, there is no general consensus about the ability of indicator taxa to predict wider trends in biodiversity. Many studies have focused on large-scale patterns of species co-occurrence to identify areas of high biodiversity, threat or endemism, but there is much less information about patterns of species co-occurrence at local scales. In this study, we assess fine-scale co-occurrence patterns of three indicator taxa (epiphytic ferns, leaf litter frogs and dung beetles) across a remotely sensed gradient of human disturbance in the Ecuadorian Amazon. We measure the relative contribution of rare and common species to patterns of total richness in each taxon and determine the ability of common and rare species to act as surrogate measures of human disturbance and each other. We find that the species richness of indicator taxa changed across the human disturbance gradient but that the response differed among taxa, and between rare and common species. Although we find several patterns of co-occurrence, these patterns differed between common and rare species. Despite showing complex patterns of species co-occurrence, our results suggest that species or taxa can act as reliable indicators of each other but that this relationship must be established and not assumed. PMID:22701730

  6. Co-occurrence patterns of common and rare leaf-litter frogs, epiphytic ferns and dung beetles across a gradient of human disturbance.

    PubMed

    Oldekop, Johan A; Bebbington, Anthony J; Truelove, Nathan K; Tysklind, Niklas; Villamarín, Santiago; Preziosi, Richard F

    2012-01-01

    Indicator taxa are commonly used to identify priority areas for conservation or to measure biological responses to environmental change. Despite their widespread use, there is no general consensus about the ability of indicator taxa to predict wider trends in biodiversity. Many studies have focused on large-scale patterns of species co-occurrence to identify areas of high biodiversity, threat or endemism, but there is much less information about patterns of species co-occurrence at local scales. In this study, we assess fine-scale co-occurrence patterns of three indicator taxa (epiphytic ferns, leaf litter frogs and dung beetles) across a remotely sensed gradient of human disturbance in the Ecuadorian Amazon. We measure the relative contribution of rare and common species to patterns of total richness in each taxon and determine the ability of common and rare species to act as surrogate measures of human disturbance and each other. We find that the species richness of indicator taxa changed across the human disturbance gradient but that the response differed among taxa, and between rare and common species. Although we find several patterns of co-occurrence, these patterns differed between common and rare species. Despite showing complex patterns of species co-occurrence, our results suggest that species or taxa can act as reliable indicators of each other but that this relationship must be established and not assumed. PMID:22701730

  7. Classification and distribution of large intestinal bacteria in nonhibernating and hibernating leopard frogs (Rana pipiens).

    PubMed Central

    Banas, J A; Loesche, W J; Nace, G W

    1988-01-01

    The large intestinal flora of the leopard frog, Rana pipiens, was examined to determine whether differences existed between the nonhibernating and hibernating states of the animal and to determine the relative concentrations and proportions of potential frog pathogens. Hibernators had a logarithmic decrease of bacteria per milligram of intestine averaging one, and significantly greater proportions of facultative bacteria and psychrophiles relative to nonhibernators. The predominant anaerobic bacteria were gram-positive Clostridium species and gram-negative Bacteroides and Fusobacterium species. The predominant facultative bacteria were enterobacteria in nonhibernators but Pseudomonas species in hibernators. Many species of Pseudomonas are pathogenic for frogs, and thus the intestinal flora in hibernators may be a potential source of infectious disease. PMID:3263838

  8. Columbia spotted frog (Rana luteiventris) in southeastern Oregon: A survey of historical localities, 2009

    USGS Publications Warehouse

    Pearl, Chistopher A.; Galvan, Stephanie K.; Adams, Michael J.; McCreary, Brome

    2010-01-01

    The Columbia spotted frog (Rana luteiventris) occupies a large range in western North America and is comprised of at least three genetic units. Concern exists regarding the status of the Great Basin populations in Oregon, Idaho, and Nevada. We surveyed target and nearby alternate sites on public lands in southeastern Oregon where there was evidence that Columbia spotted frogs were historically present. We found the species at 59.5 percent (25 of 42) of target or nearby alternate sites. They were in 15 of 23 permanent streams and 8 of 13 intermittent streams. Our surveys do not provide evidence of widespread population losses in our sites. Interpretation of status of Columbia spotted frogs in this study is limited by a lack of precision in some of the historical locations and by our inability to determine if locations where only adults were indicated in the historical record once had breeding populations. Our results support the need for continued investigation of these populations.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  10. Wet but not slippery: boundary friction in tree frog adhesive toe pads

    PubMed Central

    Federle, W; Barnes, W.J.P; Baumgartner, W; Drechsler, P; Smith, J.M

    2006-01-01

    Tree frogs are remarkable for their capacity to cling to smooth surfaces using large toe pads. The adhesive skin of tree frog toe pads is characterized by peg-studded hexagonal cells separated by deep channels into which mucus glands open. The pads are completely wetted with watery mucus, which led previous authors to suggest that attachment is solely due to capillary and viscous forces generated by the fluid-filled joint between the pad and the substrate. Here, we present evidence from single-toe force measurements, laser tweezer microrheometry of pad mucus and interference reflection microscopy of the contact zone in Litoria caerulea, that tree frog attachment forces are significantly enhanced by close contacts and boundary friction between the pad epidermis and the substrate, facilitated by the highly regular pad microstructure. PMID:16971337

  11. The reproductive biology and larvae of the first tadpole-bearing frog, Limnonectes larvaepartus.

    PubMed

    Kusrini, Mirza D; Rowley, Jodi J L; Khairunnisa, Luna R; Shea, Glenn M; Altig, Ronald

    2015-01-01

    Most of the reproductive modes of frogs include an exotrophic tadpole, but a number of taxa have some form of endotrophic development that lacks a feeding tadpole stage. The dicroglossid frog genus Limnonectes ranges from China south into Indonesia. The breeding biologies of the approximately 60 described species display an unusual diversity that range from exotrophic tadpoles to endotrophic development in terrestrial nests. There have been mentions of oviductal production of typical, exotrophic tadpoles in an undescribed species of Limnonectes from Sulawesi, Indonesia. Here we examine newly collected specimens of this species, now described as L. larvaepartus and present the first substantial report on this unique breeding mode. Typical exotrophic tadpoles that are retained to an advanced developmental stage in the oviducts of a female frog are birthed into slow-flowing streams or small, non-flowing pools adjacent to the streams. PMID:25555000

  12. Infection risk to travelers going to dengue fever endemic regions.

    PubMed

    Pongsumpun, P; Patanarapelert, K; Sriprom, M; Varamit, S; Tang, I M

    2004-03-01

    The risk of dengue virus infection to travelers visiting dengue fever endemic regions was studied through the use of mathematical modeling. A Susceptible-Infected-Recovered (SIR) model is used to describe the transmission of dengue fever (DF) in an endemic region into which tourists enter. The dynamics of a new class of human, the traveler, is incorporated into the systems of first order differential equations in the SIR describing the dynamics of the transmission in the host region. Using standard dynamic analysis methods, the numbers of travelers who become infected with the dengue virus are calculated as a function of the length of time the tourist stays in the region. PMID:15272760

  13. Measuring malaria endemicity from intense to interrupted transmission

    PubMed Central

    Hay, Simon I; Smith, David L; Snow, Robert W

    2008-01-01

    Summary The quantification of malaria transmission for the classification of malaria risk has long been a concern for epidemiologists. During the era of the Global Malaria Eradication Programme, measurements of malaria endemicity were institutionalised by their incorporation into rules outlining defined action points for malaria control programmes. We review the historical development of these indices and their contemporary relevance. This is at a time when many malaria-endemic countries are scaling-up their malaria control activities and reconsidering their prospects for elimination. These considerations are also important to an international community that has recently been challenged to revaluate the prospects for malaria eradication. PMID:18387849

  14. Enteropathogenic Escherichia coli Serotypes and Endemic Diarrhea in Infants

    PubMed Central

    Toledo, M. Regina F.; Alvariza, M. do Carmo B.; Murahovschi, Jayme; Ramos, Sonia R. T. S.; Trabulsi, Luiz R.

    1983-01-01

    Enteropathogenic Escherichia coli serotypes were searched for in feces of 550 children with endemic diarrhea and in 129 controls, in São Paulo, in 1978 and 1979; serotypes O111ab:H−, O111ab:H2, and O119:H6 were significantly associated with diarrhea in children 0 to 5 months old and were the most frequent agents of diarrhea in this age group as compared with enterotoxigenic and enteroinvasive E. coli, Salmonella sp., Shigella sp., and Yersinia enterocolitica. It is concluded that various enteropathogenic E. coli serotypes may be agents of endemic infantile diarrhea. PMID:6339384

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

    PubMed

    Yan, Fang; Jiang, Ke; Wang, Kai; Jin, Jie-Qiong; Suwannapoom, Chatmongkon; Li, Cheng; Vindum, Jens V; Brown, Rafe M; Che, Jing

    2016-01-18

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-01-01

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

  18. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

    USGS Publications Warehouse

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

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and

  19. Application of Surface-Water Microlayer Sampler in the Hydrologic Assessment of Frog Malformations in Minnesota

    NASA Astrophysics Data System (ADS)

    Jones, P. M.; Menheer, M. A.; Taylor, H.; Aiken, G.; Peart, D.; Thurman, E. M.; Scribner, E. A.; Weishaar, J.; Rostad, C.; Rosenberry, D.

    2001-12-01

    Since the summer of 1993, frog malformations have been reported throughout North America, including over 150 sites in 54 counties of Minnesota. Water-quality analyses of bulk water (grab) samples collected at more than 20 frog malformation sites have yet to indicate any direct relationships between water quality and frog malformation rates. However, many potential contaminants to frog egg masses, metamorphs, and adults are hydrophobic or have a strong association with floating particles that may accumulate in microlayers found on the surface of water bodies. To assess surface microlayer chemistry, a radio-controlled catamaran sampler was developed to collect hydrophobic microlayer samples using a rotating Teflon-coated drum. The drum was positioned to sit approximately 0.5 inch in the surface-water body. Samples were collected on the rotating drum, extracted off the rotating drum using a series of wiper-blades, and funneled into Teflon collection pans. A series of water samples were collected using three different techniques to determine if any relationships exist between the water quality of the surface microlayer and/or lower waters and frog malformation rates. Grab, upper-surface, and microlayer samples were collected during June, August and October 2001 at four surface-water bodies. Grab samples were collected through Teflon tubing held throughout the vertical water column, while upper-surface water samples were collected through Teflon tubing held at the water surface. Microlayer samples were collected using the designed sampler. Collected water samples were analyzed for major ions, trace elements, nutrients, total mercury, dissolved organic carbon, pesticides, hormones, isoflavones, and a series of waste-water constituents. In 2000, frog malformation rates were above 5% at two of the sites, and rates were less than 1% at the other two sites. Available results from water-quality analyses will be presented.

  20. Epidermal laser stimulation of action potentials in the frog sciatic nerve

    NASA Astrophysics Data System (ADS)

    Jindra, Nichole M.; Goddard, Douglas; Imholte, Michelle; Thomas, Robert J.

    2010-01-01

    Measurements of laser-stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) are made using two infrared lasers. The dorsal sides of the frog's hind limbs are exposed to short-pulsed 1540- and 1064-nm wavelengths at three separate spot sizes: 2, 3, and 4 mm. Energy density thresholds are determined for eliciting an action potential at each experimental condition. Results from these exposures show similar evoked potential thresholds for both wavelengths. The 2-mm-diam spot sizes yield action potentials at radiant exposure levels almost double that seen with larger beam sizes.

  1. Leap Frog Digital Sensors and Definition, Integration & Testing FY 2003 Annual Report

    SciTech Connect

    Meitzler, Wayne D.; Ouderkirk, Steven J.; Shoemaker, Steven V.; Tzemos, Spyridon; Griswold, Richard L.

    2003-12-31

    The objective of Leap Frog is to develop a comprehensive security tool that is transparent to the user community and more effective than current methods for preventing and detecting security compromises of critical physical and digital assets. Current security tools intrude on the people that interact with these critical assets by requiring them to perform additional functions or having additional visible sensors. Leap Frog takes security to the next level by being more effective and reducing the adverse impact on the people interacting with protected assets.

  2. Breeding chorus indices are weakly related to estimated abundance of boreal chorus frogs

    USGS Publications Warehouse

    Corn, P.S.; Muths, E.; Kissel, A.M.; Scherer, R. D.

    2011-01-01

    Call surveys used to monitor breeding choruses of anuran amphibians generate index values that are frequently used to represent the number of male frogs present, but few studies have quantified this relationship. We compared abundance of male Boreal Chorus Frogs (Pseudacris maculata), estimated using capture–recapture methods in two populations in Colorado, to call index values derived from automated recordings. Single index values, such as might result from large monitoring efforts, were unrelated to population size. A synthetic call saturation index (CSI), the daily proportion of the maximum possible sum of index values derived from multiple recordings, was greater in larger populations, but the relationship was not highly predictive.

  3. Extinction of montane populations of the northern leopard frog (Rana pippins) in Colorado

    USGS Publications Warehouse

    Corn, Paul Stephen; Fogleman, James C.

    1984-01-01

    Between 1973 and 1982 nine populations of the northern leopard frog in the Red Feather Lakes region of Larimer County, Colorado, failed in reproduce. These failures all resulted in extinction of the populations. One area formerly supporting a population was recolonized in 1980, but no frogs were observed at any of the nine sites in 1981 or 1982. Six of the populations went extinct because the breeding ponds dried up. The remaining populations were small enough to be susceptible to random events, but the nature of these events is unknown.

  4. Temperature-dependent elaboration of collagenase by the renal adenocarcinoma of the leopard frog, Rana pipiens.

    PubMed

    Ogilvie, D J; McKinnell, R G; Tarin, D

    1984-08-01

    Naturally occurring renal adenocarcinoma in North American leopard frogs, Rana pipiens, metastasize frequently (77%) when these ectothermic animals are kept in a warm environment but not when they are kept cold. We have found that explants of these tumors secrete collagenase, an enzyme capable of dissolving connective tissue fibers and found previously to be closely correlated with metastatic colony-forming capability of murine mammary tumors, and that the amount released sequentially rises and falls as the ambient temperature is shifted between metastasis-permissive and -inhibitory levels. In contrast, normal frog renal tissue has low collagenase output, unaffected by temperature changes. PMID:6331646

  5. [NAG-infection in grass frogs (Rana temporaria) subjected to hypothermia].

    PubMed

    Avtsyn, A P; Shakhlamov, V A; Trager, R S; Timashkevich, T B; Poliakova, G P

    1976-12-01

    Rana temporaria kept under hypothermic conditions approaching anabiosis were inoculated with NAG-vibrios and examined clinically, bacteriologically, histologically, and electron microscopically. Oral inoculation of hypothermic frogs with NAG-vibrios resulted in 18 to 24 hours in the development of acute NAG-infection resembling the cholera-like syndrome, and characterized by general intoxication and local enteropathogenic effects. NAG-vibrios persisted in the frog gastrointestinal tract for a long time after the cessation of the acute period of the disease. PMID:1088086

  6. Ion secretion and isotonic transport in frog skin glands.

    PubMed

    Ussing, H H; Lind, F; Larsen, E H

    1996-07-01

    The aim of this study was to clarify the mechanism of isotonic fluid transport in frog skin glands. Stationary ion secretion by the glands was studied by measuring unidirectional fluxes of 24Na+, 42K+, and carrier-free 134Cs+ in paired frog skins bathed on both sides with Ringer's solution, and with 10(-5) M noradrenaline on the inside and 10(-4) M amiloride on the outside. At transepithelial thermodynamic equilibrium conditions, the 134Cs+ flux ratio, JoutCs/JinCs, varied in seven pairs of preparations from 6 to 36. Since carrier-free 134Cs+ entering the cells is irreversibly trapped in the cellular compartment (Ussing & Lind, 1996), the transepithelial net flux of 134Cs+ indicates that a paracellular flow of water is dragging 134Cs+ in the direction from the serosal- to outside solution. From the measured flux ratios it was calculated that the force driving the secretory flux of Cs+ varied from 30 to 61 mV among preparations. In the same experiments unidirectional Na+ fluxes were measured as well, and it was found that also Na+ was subjected to secretion. The ratio of unidirectional Na+ fluxes, however, was significantly smaller than would be predicted if the two ions were both flowing along the paracellular route dragged by the flow of water. This result indicates that Na+ and Cs+ do not take the same pathway through the glands. The flux ratio of unidirectional K+ fluxes indicated active secretion of K+. The time it takes for steady-state K+ fluxes to be established was significantly longer than that of the simultaneously measured Cs+ fluxes. These results allow the conclusion that - in addition to being transported between cells - K+ is submitted to active transport along a cellular pathway. Based on the recirculation theory, we propose a new model which accounts for stationary Na+, K+, Cl- and water secretion under thermodynamic equilibrium conditions. The new features of the model, as compared to the classical Silva-model for the shark-rectal gland, are: (i

  7. Myofilament spacing and force generation in intact frog muscle fibres.

    PubMed Central

    Bagni, M A; Cecchi, G; Colomo, F

    1990-01-01

    1. The relation between sarcomere length and steady tetanic tension was determined at 10-12 degrees C for 70-80 microns long length-clamped segments of single fibres isolated from the tibialis anterior muscle of the frog, in normal and hypertonic or hypotonic Ringer solutions. 2. The tension depression and potentiation observed in hypertonic and hypotonic Ringers solutions varied with sarcomere length, so that, as opposed to myofilament overlap predictions, the optimum length for tension development was shorter in hypertonic Ringer solution and longer in hypotonic Ringer solution than in normal Ringer solution. As the fibres were stretched from 1.96 to 2.24 microns sarcomere length, both tension depression in hypertonic Ringer solution and tension potentiation in hypotonic Ringer solution increased by 9 and 5%, respectively. 3. Within this range of sarcomere lengths the length-stiffness relation in hypotonic and in hypertonic Ringer solutions exhibit little or no change relative to that in normal Ringer solution. 4. The results indicate that separation between the thick and the thin myofilaments influences the mechanism of force generation. There is an optimum interfilament distance (10-12 nm surface to surface between the thick and the thin filaments) for tension production. In isotonic Ringer solution, this corresponds to the interfilament distance at sarcomere lengths around 2.10 microns. The force per attached cross-bridge, rather than their number, appears to decrease as the interfilament distance is brought above or below the optimum length. Even if this effect is moderate in isotonic Ringer solution, it should be taken into account in models of the force-generation mechanism. PMID:2086776

  8. High susceptibility of the endangered dusky gopher frog to ranavirus.

    PubMed

    Sutton, William B; Gray, Matthew J; Hardman, Rebecca H; Wilkes, Rebecca P; Kouba, Andrew J; Miller, Debra L

    2014-11-13

    Amphibians are one of the most imperiled vertebrate groups, with pathogens playing a role in the decline of some species. Rare species are particularly vulnerable to extinction because populations are often isolated and exist at low abundance. The potential impact of pathogens on rare amphibian species has seldom been investigated. The dusky gopher frog Lithobates sevosus is one of the most endangered amphibian species in North America, with 100-200 individuals remaining in the wild. Our goal was to determine whether adult L. sevosus were susceptible to ranavirus, a pathogen responsible for amphibian die-offs worldwide. We tested the relative susceptibility of adult L. sevosus to ranavirus (103 plaque-forming units) isolated from a morbid bullfrog via 3 routes of exposure: intra-coelomic (IC) injection, oral (OR) inoculation, and water bath (WB) exposure. We observed 100% mortality of adult L. sevosus in the IC and WB treatments after 10 and 19 d, respectively. Ninety-five percent mortality occurred in the OR treatment over the 28 d evaluation period. No mortality was observed in the control treatment after 28 d. Our results indicate that L. sevosus is susceptible to ranavirus, and if adults in the wild are exposed to this pathogen, significant mortality could occur. Additionally, our study demonstrates that some adult amphibian species can be very susceptible to ranavirus, which has been often overlooked in North American studies. We recommend that conservation planners consider testing the susceptibility of rare amphibian species to ranavirus and that the adult age class is included in future challenge experiments. PMID:25392038

  9. Hylid frog phylogeny and sampling strategies for speciose clades.

    PubMed

    Wiens, John J; Fetzner, James W; Parkinson, Christopher L; Reeder, Tod W

    2005-10-01

    How should characters and taxa be sampled to resolve efficiently the phylogeny of ancient and highly speciose groups? We addressed this question empirically in the treefrog family Hylidae, which contains > 800 species and may be nonmonophyletic with respect to other anuran families. We sampled 81 species (54 hylids and 27 outgroups) for two mitochondrial genes (12S, ND1), two nuclear genes (POMC, c-myc), and morphology (144 characters) in an attempt to resolve higher-level relationships. We then added 117 taxa to the combined data set, many of which were sampled for only one gene (12S). Despite the relative incompleteness of the majority of taxa, the resulting trees placed all taxa in the expected higher-level clades with strong support, despite some taxa being > 90% incomplete. Furthermore, we found no relationship between the completeness of a taxon and the support (parsimony bootstrap or Bayesian posterior probabilities) for its localized placement on the tree. Separate analysis of the data set with the most taxa (12S) gives a somewhat problematic estimate of higher-level relationships, suggesting that data sets scored only for some taxa (ND1, nuclear genes, morphology) are important in determining the outcome of the combined analysis. The results show that hemiphractine hylids are not closely related to other hylids and should be recognized as a distinct family. They also show that the speciose genus Hyla is polyphyletic, but that its species can be arranged into three monophyletic genera. A new classification of hylid frogs is proposed. Several potentially misleading signals in the morphological data are discussed. PMID:16243760

  10. Does multiple paternity improve fitness of the frog Crinia georgiana?

    PubMed

    Byrne, P G; Roberts, J D

    2000-06-01

    In the Australian myobatrachid frog Crinia georgiana simultaneous polyandry occurs in about half of all matings, which leads to multiple paternity, but reduced fertilization success and occasional female mortality. Multiple paternity may provide benefits to females that compensate for these costs, for example, through enhanced genetic diversity of a clutch. In nature, embryos and tadpoles of C. georgiana develop in shallow, temporary pools and may be exposed to fluctuating water levels and the risk of desiccation between rain events. Fertilization by genetically diverse sires may act as a bet hedge against these conditions. To evaluate this hypothesis, females were artificially mated with one or two males in the field and eggs and larvae reared in the laboratory under constant or fluctuating developmental conditions. Experiment 1 exposed embryos from single- and multiple-paternity clutches to conditions where eggs were completely covered during development or eggs sat in air on a moist substrate. Experiment 2 exposed freshly hatched larvae from single- and multiple-paternity clutches to constant wet conditions, where larvae were completely covered, or fluctuating wet conditions, where larvae ranged from being completely submersed to partially exposed over a 13-day cycle. We measured mean performance and best performance as alternate measures of genetic benefits. There were no effects of paternity on percent survival to hatching, time to hatching, body size at hatching, percent survival to metamorphosis, time to metamorphosis, or body size at metamorphosis. We also analyzed variance within clutches as a measure of genetic diversity. Again there were no predictable effects of multiple paternity. Polyandry does not appear to provide any genetic benefits that compensate for the high costs of polyandry in this species. PMID:10937269

  11. Cost-effective conservation of an endangered frog under uncertainty.

    PubMed

    Rose, Lucy E; Heard, Geoffrey W; Chee, Yung En; Wintle, Brendan A

    2016-04-01

    How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well-developed tools exist for prioritizing areas for one-time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost-effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost-effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost-effectiveness analysis. This allowed us to discern between cost-effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost-effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost-effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost-effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost

  12. A tree of tree frogs around the Black Sea.

    PubMed

    Irwin, Darren E

    2016-09-01

    Speciation, the process by which one species evolves into two or more, is a major focus of ongoing debate, particularly regarding the geographic context in which it occurs. Geographic models of speciation tend to fall into discrete categories, typically referred to as allopatric, parapatric and sympatric speciation, according to whether two groups evolve reproductive isolation while geographically isolated, differentiated but connected by gene flow, or completely co-occurring. Yet molecular studies indicate that full development of reproductive isolation can take very long compared with the timescale at which climatic oscillations occur, such that the geographic context of differentiating forms might change often during the long process to full species. Studies of genetic relationships across the ranges of organisms with low-dispersal distances have the potential to reveal these complex histories. In a particularly elegant example in this issue, Dufresnes et al. () use genetic variation and ecological niche modelling to show that a ring of populations of the eastern tree frog (Hyla orientalis) surrounding the Black Sea had a complex history of geographic differentiation. Alternating phases of geographic fragmentation and phases of gene flow between neighbouring populations have produced a pattern of gradual genetic change connecting the western, southern and eastern sides of the ring, with the northwestern and northeastern forms being most differentiated. In the north, a population in Crimea appears to have been produced through mixture of the two extreme forms. The overall genetic relationships are reminiscent of those found in ring species, which have been used as prime demonstrations of the process of speciation. The difference, however, is that the terminal forms appear to have mixed rather than be reproductively isolated, although more research is needed to infer whether there might be some reproductive isolation on the northern side of the ring. PMID

  13. The actions of tubocurarine at the frog neuromuscular junction.

    PubMed Central

    Colquhoun, D; Dreyer, F; Sheridan, R E

    1979-01-01

    1. The action of tubocurarine on voltage-clamped frog muscle end-plates has been re-examined by means (a) equilibrium dose-ratio measurements, (b) current fluctuation measurements and (c) voltage-jump relaxation measurements. 2. The equilibrium measurements can be interpreted as implying that tubocurarine has (a) a competitive blocking action, with a dissociation constant of 0.34 microM, which is not dependent on membrane potential, and (b) an additional voltage-dependent blocking action. 3. In the presence of tubocurarine two kinetic components can be seen. The faster one is similar to, but rather faster than, the normal ion channel closing rate. The other is much slower (1--3 sec), and, in relaxation experiments it is in the opposite direction to the fast relaxation. 4. A number of alternative explanations for the results are discussed. The mechanism that fits them best appears to be a combination of competitive block (or block of shut channels), with a strongly voltage-dependent block of open ion channels by tubocurarine. Estimates of the rate constants for channel blocking (and their voltage dependence) are derived. From these estimates the dissociation constant for the binding of tubocurarine to open channels appears to be roughly 0.12 microM at --70 mV and 0.02 microM at --12 mV. 5. Several potential sources of error in the experiments, and in their interpretation, are discussed. The most serious of these are problems associated with diffusion in the small volume of the synaptic cleft, viz. (a) changes in cleft concentration consequent on changes in binding, and (b) ionophoretic flux of antagonist and agonist into the synaptic cleft. PMID:315462

  14. Light-dependent magnetic compass in Iberian green frog tadpoles

    NASA Astrophysics Data System (ADS)

    Diego-Rasilla, Francisco Javier; Luengo, Rosa Milagros; Phillips, John B.

    2010-12-01

    Here, we provide evidence for a wavelength-dependent effect of light on magnetic compass orientation in Pelophylax perezi (order Anura), similar to that observed in Rana catesbeiana (order Anura) and Notophthalmus viridescens (order Urodela), and confirm for the first time in an anuran amphibian that a 90° shift in the direction of magnetic compass orientation under long-wavelength light (≥500 nm) is due to a direct effect of light on the underlying magnetoreception mechanism. Although magnetic compass orientation in other animals (e.g., birds and some insects) has been shown to be influenced by the wavelength and/or intensity of light, these two amphibian orders are the only taxa for which there is direct evidence that the magnetic compass is light-dependent. The remarkable similarities in the light-dependent magnetic compasses of anurans and urodeles, which have evolved as separate clades for at least 250 million years, suggest that the light-dependent magnetoreception mechanism is likely to have evolved in the common ancestor of the Lissamphibia (Early Permian, ~294 million years) and, possibly, much earlier. Also, we discuss a number of similarities between the functional properties of the light-dependent magnetic compass in amphibians and blue light-dependent responses to magnetic stimuli in Drosophila melanogaster, which suggest that the wavelength-dependent 90° shift in amphibians may be due to light activation of different redox forms of a cryptochrome photopigment. Finally, we relate these findings to earlier studies showing that the pineal organ of newts is the site of the light-dependent magnetic compass and recent neurophysiological evidence showing magnetic field sensitivity in the frog frontal organ (an outgrowth of the pineal).

  15. Induction of apoptosis in frog virus 3-infected cells.

    PubMed

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  16. Frog Virus 3 DNA Replication Occurs in Two Stages

    PubMed Central

    Goorha, R.

    1982-01-01

    Viral DNA synthesis in frog virus 3 (FV3)-infected cells occurs both in the nucleus and in the cytoplasm (Goorha et al., Virology 84:32-51, 1978). Relationships between viral DNA molecules synthesized in these two compartments and their role in the virus replication were examined. The data presented here suggest that (i) FV3 DNA replicated in two stages and (ii) nucleus and cytoplasm were the sites of stages 1 and 2 of DNA replication, respectively. Stages 1 and 2 were further distinguished by their temporal appearance during infection and by the sizes of the replicating DNA as determined by sedimentation in neutral sucrose gradients. In stage 1, replicating molecules, between the size of unit and twice the unit length, were produced early in infection (2 h postinfection). In contrast, stage 2 of DNA replication occurred only after 3 h postinfection, and replicating molecules were large concatemers. Results of pulse-chase experiments showed that the concatemeric DNA served as the precursor for the production of mature FV3 DNA. Denaturation of concatemeric DNA with alkali or digestion with S1 nuclease reduced it to less than genome size molecules, indicating the presence of extensive single-stranded regions. Analysis of replicating DNA by equilibrium centrifugation in CsCl gradients after a pulse-chase suggested that these single-stranded regions were subsequently repaired. Based on these and previous data, a scheme of FV3 replication is presented. According to this scheme, FV3 utilizes the nucleus for early transcription and stage 1 of DNA replication. The viral DNA is then transported to the cytoplasm, where it participates in stage 2 DNA replication to form a concatemeric replication complex. The processing of concatemers to produce mature viral DNA and virus assembly also occurs in the cytoplasm. This mode of replication is strikingly different from any other known DNA virus. PMID:7109033

  17. ESTIMATES OF ENDEMIC WATERBORNE ILLNESS FROM COMMUNITY INTERVENTION STUDIES

    EPA Science Inventory

    The nature and magnitude of endemic waterborne disease are not well characterized in the

    United States. Epidemiologic studies of various designs can provide an estimate of the

    waterborne attributable risk along with other types of information. Community drinking wat...

  18. Screening of traditionally used endemic Soqotraen plants for cytotoxic activity.

    PubMed

    Ali, Nasser A Awadh; Mothana, Ramzi; Ghaleb, Nasr Abdo; Lindequist, Ulrike

    2007-01-01

    Thirty extracts obtained from 10 endemic plant species belonging to 8 plant families used in the traditional medicine in Socotra have been tested for cytotoxic activity against FL-cells. Extracts of Eureiandra balfourii and Commiphora ornifolia showed the strongest activity against FL-cells with IC(50) < 10 microg/ml and 39.3 microg/ml respectively. PMID:20161922

  19. Salmonella serotype shift during an endemic dairy infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairy farms are known reservoirs for Salmonella spp. and control of this organism is challenging. Salmonellae have been shown to be endemic in herds in part because they are easily spread between animals and throughout the farm environment. The impact of the infection on the herd is variable and dep...

  20. Small Town Tales: Endemic Performance in Rural America.

    ERIC Educational Resources Information Center

    Klinger-Vartabedian, Laurel; Cregan, Lori

    Storytelling is a performance medium which is enhanced by the qualities indigenous to small towns: collective memory and common history. A type of narrative peculiar to small towns, the community-wide anecdote, is one example of storytelling. The transmittal of such tales is termed "endemic performance" because the retelling of the tales could…

  1. Endemic Mimosa species from Mexico prefer alphaproteobacterial rhizobial symbionts.

    PubMed

    Bontemps, Cyril; Rogel, Marco Antonio; Wiechmann, Anja; Mussabekova, Assel; Moody, Sarah; Simon, Marcelo F; Moulin, Lionel; Elliott, Geoffrey N; Lacercat-Didier, Laurence; Dasilva, Cindy; Grether, Rosaura; Camargo-Ricalde, Sara L; Chen, Weimin; Sprent, Janet I; Martínez-Romero, Esperanza; Young, J Peter W; James, Euan K

    2016-01-01

    The legume genus Mimosa has > 500 species, with two major centres of diversity, Brazil (c. 350 spp.) and Mexico (c. 100 spp.). In Brazil most species are nodulated by Burkholderia. Here we asked whether this is also true of native and endemic Mexican species. We have tested this apparent affinity for betaproteobacteria by examining the symbionts of native and endemic species of Mimosa in Mexico, especially from the central highlands where Mimosa spp. have diversified. Nodules were tested for betaproteobacteria using in situ immunolocalization. Rhizobia isolated from the nodules were genetically characterized and tested for their ability to nodulate Mimosa spp. Immunological analysis of 25 host taxa suggested that most (including all the highland endemics) were not nodulated by betaproteobacteria. Phylogenetic analyses of 16S rRNA, recA, nodA, nodC and nifH genes from 87 strains isolated from 20 taxa confirmed that the endemic Mexican Mimosa species favoured alphaproteobacteria in the genera Rhizobium and Ensifer: this was confirmed by nodulation tests. Host phylogeny, geographic isolation and coevolution with symbionts derived from very different soils have potentially contributed to the striking difference in the choice of symbiotic partners by Mexican and Brazilian Mimosa species. PMID:26214613

  2. Trichomonad infection in endemic and introduced columbids in the Seychelles.

    PubMed

    Bunbury, N

    2011-07-01

    Island endemic avifaunas face many threats, including the now well-documented impacts of pathogens. The impacts of pathogens on the endemic Seychelles avifauna, however, have been little studied. The protozoan parasite Trichomonas gallinae has been shown to reduce survival and reproductive success of the endemic Pink Pigeon Columba mayeri on the nearby island of Mauritius. I investigated trichomonad infection prevalence and pathogenicity in endemic Seychelles Blue Pigeons, Alectroenas pulcherrima, and two introduced species of columbid, the Madagascar Turtle-dove, Streptopelia picturata, and the Barred Ground Dove, Geopelia striata, on the Seychelles island of Mahé during September-October 2007. I asked whether: 1) trichomonad infections occur in these species; 2) prevalence varies among species; and 3) birds show any signs of pathogenicity consistent with tricho-monosis. I use the results to assess the potential threat of this pathogen to A. pulcherrima. All three species were infected with trichomonads, and the overall prevalence was 27.5%. Alectroenas pulcherrima had higher prevalence (47.1%) than the two introduced species combined (24.3%). No infected individuals showed any signs of disease. These findings suggest that trichomonad parasites should be considered as a potential disease threat to the A. pulcherrima population. PMID:21719842

  3. Studies on bilharziasis endemicity in the vicinity of Basra, Iraq*

    PubMed Central

    Najarian, H. H.; de Araoz, J.; Klimt, C. R.; al Ani, K.; Azzawi, J.

    1961-01-01

    This paper reports on investigations into the distribution of snail genera and possible limiting environmental factors in the endemic and non-endemic areas of human bilharziasis in and near Basra, carried out in 1958 by the WHO Bilharziasis Control Project staff in Iraq. These investigations confirmed the existence of an abrupt line of demarcation between these areas immediately south of Basra. During June and October 1958, the known intermediate snail host, Bulinus truncatus, was not found in canals bordering on areas of either infected or non-infected human populations. From these findings and the evidence of previous investigations it is concluded that in southern Iraq, and particularly in Basra, B. truncatus has been demonstrated with difficulty, if at all. Nevertheless, transmission has continued to take place. Explanations of this apparent phenomenon are discussed and it is concluded that populations of B. truncatus may be completely absent for several years and that other snail genera may play a role in transmitting the disease. A study of environmental factors indicates that water velocities, salinity, turbidity, and pH in the endemic and non-endemic areas showed no significant differences, but that the continuous change in water flow may be a factor limiting B. truncatus colonization. It is also concluded that the salinity in the Shatt al Arab River originates from Lake Hammar and is not introduced from the Persian Gulf by tidal wave, as has been previously believed. PMID:14478047

  4. Collection of Helianthus exilis, an endemic serpentine sunflower of California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Helianthus consists of 51 species (14 annual and 37 perennial), all restricted to North America. Serpentine sunflower, Helianthus exilis A. Gray, is endemic to the serpentine soils of the Coastal Range and Sierra Nevada mountains of California and is a potential source of useful genes for ...

  5. Global patterns in endemism explained by past climatic change.

    PubMed

    Jansson, Roland

    2003-03-22

    I propose that global patterns in numbers of range-restricted endemic species are caused by variation in the amplitude of climatic change occurring on time-scales of 10-100 thousand years (Milankovitch oscillations). The smaller the climatic shifts, the more probable it is that palaeoendemics survive and that diverging gene pools persist without going extinct or merging, favouring the evolution of neoendemics. Using the change in mean annual temperature since the last glacial maximum, estimated from global circulation models, I show that the higher the temperature change in an area, the fewer endemic species of mammals, birds, reptiles, amphibians and vascular plants it harbours. This relationship was robust to variation in area (for areas greater than 10(4) km2), latitudinal position, extent of former glaciation and whether or not areas are oceanic islands. Past climatic change was a better predictor of endemism than annual temperature range in all phylads except amphibians, suggesting that Rapoport's rule (i.e. species range sizes increase with latitude) is best explained by the increase in the amplitude of climatic oscillations towards the poles. Globally, endemic-rich areas are predicted to warm less in response to greenhouse-gas emissions, but the predicted warming would cause many habitats to disappear regionally, leading to species extinctions. PMID:12769457

  6. Ecological predictors of extinction risks of endemic mammals of China.

    PubMed

    Chen, You-Hua

    2014-07-01

    In this brief report, we analyzed ecological correlates of risk of extinction for mammals endemic to China using phylogenetic eigenvector methods to control for the effect of phylogenetic inertia. Extinction risks were based on the International Union for Conservation of Nature (IUCN) Red List and ecological explanatory attributes that include range size and climatic variables. When the effect of phylogenetic inertia were controlled, climate became the best predictor for quantifying and evaluating extinction risks of endemic mammals in China, accounting for 13% of the total variation. Range size seems to play a trivial role, explaining ~1% of total variation; however, when non-phylogenetic variation partitioning analysis was done, the role of range size then explained 7.4% of total variation. Consequently, phylogenetic inertia plays a substantial role in increasing the explanatory power of range size on the extinction risks of mammals endemic to China. Limitations of the present study are discussed, with a focus on under-represented sampling of endemic mammalian species. PMID:25017756

  7. RISK FACTORS FOR ENDEMIC GASTROINTESTINAL ILLNESS AMONG A WASHINGTON COHORT

    EPA Science Inventory

    RISK FACTORS FOR ENDEMIC GASTROINTESTINAL ILLNESS AMONG A WASHINGTON COHORT

    *Christina A. Peterson 1,2,3 and Rebecca L. Calderon 2

    1 Department of Epidemiology
    School of Public Health (SPH)
    University of North Carolina at Chapel Hill (UNC-CH), 27516
    2 Nat...

  8. Acid-shock, aluminium, and presence of Sphagnum aurantiacum: effect on embryological development in the common frog, Rana temporaria and the moor frog, Rana arvalis

    SciTech Connect

    Olsson, M.; Hogstrand, C.; Dahlberg, A.; Berglind, S.A.

    1987-07-01

    During the last two decades, several effects of acidification have been shown, e.g., enhanced leaching of metals from sediments and soil. Furthermore, an increased growth of Sphagnum aurantiacum frequently occurs in acidified waters. The aim of the present study is to investigate some effects of acidification on the embryological development on two Anurans. The toxicity of aluminium is thought to vary with pH. The highest toxicity of aluminium in the hydroxyl form have been found at pH 5. In the present study a laboratory experiment was performed to investigate the toxicity of Al to frog embryos in water with pH 5.0. In acidified waters Sphagnum and especially S. aurantiacum, is competitive and quickly become established. It has been indicated that frog spawn deposited on Sphagnum show an unusually high mortality and questions have been raised if Sphagnum reinforces the detrimental effects of acidification on Anuran reproduction.

  9. Response of the Italian agile frog (Rana latastei) to a Ranavirus, frog virus 3: a model for viral emergence in naïve populations.

    PubMed

    Pearman, Peter B; Garner, Trenton W J; Straub, Monika; Greber, Urs F

    2004-10-01

    Ranavirus (family Iridoviridae) is a genus of pathogens of poikilotherms, and some ranaviruses may play a role in widespread mortality of amphibians. Ecology of viral transmission in amphibians is poorly known but can be addressed through experimentation in the laboratory. In this study, we use the Ranavirus frog virus 3 (FV3) as an experimental model for pathogen emergence in naive populations of tadpoles. We simulated emerging disease by exposing tadpoles of the Italian agile frog (Rana latastei), to the North American Ranavirus FV3. We demonstrated that mortality occurred due to viral exposure, exposure of tadpoles to decreasing concentrations of FV3 in the laboratory produced dose-dependent survival rates, and cannibalism of virus-carrying carcasses increased mortality due to FV3. These experiments suggest the potential for ecological mechanisms to affect the level of exposure of tadpoles to Ranavirus and to impact transmission of viral pathogens in aquatic systems. PMID:15650083

  10. Future of Endemic Flora of Biodiversity Hotspots in India

    PubMed Central

    Chitale, Vishwas Sudhir; Behera, Mukund Dev; Roy, Partha Sarthi

    2014-01-01

    India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a) regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b) mixed models provide more accurate results, compared to single variable based

  11. Future of endemic flora of biodiversity hotspots in India.

    PubMed

    Chitale, Vishwas Sudhir; Behera, Mukund Dev; Roy, Partha Sarthi

    2014-01-01

    India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a) regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b) mixed models provide more accurate results, compared to single variable based

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

    PubMed

    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. PMID:27386087

  13. Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

    USGS Publications Warehouse

    Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

    2015-01-01

    In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

  14. Changes in body fluids of the cocooning fossorial frog Cyclorana australis in a seasonally dry environment.

    PubMed

    Reynolds, Stephen J; Christian, Keith A; Tracy, Christopher R; Hutley, Lindsay B

    2011-11-01

    We investigated changes in the lymph (equivalent to plasma) and urine of the cocooning frog Cyclorana australis during the dry season in monsoonal northern Australia. Frogs in moist soil for two days were fully hydrated (lymph 220 mOsm kg(-1), urine 49 mOsm kg(-1)). From five weeks onwards the soil was dry (matric potential <-8000 kPa). Aestivating frogs at three and five months formed cocoons in shallow (<20 cm) burrows and retained bladder fluid (25-80% of standard mass). After three months, urine but not lymph osmolality was elevated. After five months, lymph (314 mOsm kg(-1)) and urine (294 mOsm kg(-1)) osmolality and urea concentrations were elevated. Urea was a major contributing osmolyte in urine and accumulated in lymph after five months. Lymph sodium concentration did not change with time, whereas potassium increased in urine after five months. Active animals had moderate lymph osmolality (252 mOsm kg(-1)), but urea concentrations remained low. Urine was highly variable in active frogs, suggesting that they tolerate variation in hydration state. Despite prolonged periods in dry soil, osmolality increase in C. australis was not severe. Aestivation in a cocoon facilitates survival in shallow burrows, but such a strategy may only be effective in environments with seasonally reliable rainfall. PMID:21777688

  15. No Flower Shall Wither; or, Horticulture in the Kingdom of the Frogs. The Cutting Edge

    ERIC Educational Resources Information Center

    Clabaugh, Gary K.

    2004-01-01

    Dedicated educators, struggling with the mandates of "No Child Left Behind" will immediately identify with the hero of this allegory. Horace is a small frog, who has a passion for gardening, and watching flowers bloom. As soon as he comes of age, Horace decides to pursue his great love of nurturing tender blooming things. He studies, diligently,…

  16. Danger comes from all fronts: predator-dependent escape tactics of túngara frogs.

    PubMed

    Bulbert, Matthew W; Page, Rachel A; Bernal, Ximena E

    2015-01-01

    The escape response of an organism is generally its last line of defense against a predator. Because the effectiveness of an escape varies with the approach behaviour of the predator, it should be advantageous for prey to alter their escape trajectories depending on the mode of predator attack. To test this hypothesis we examined the escape responses of a single prey species, the ground-dwelling túngara frog (Engystomops pustulosus), to disparate predators approaching from different spatial planes: a terrestrial predator (snake) and an aerial predator (bat). Túngara frogs showed consistently distinct escape responses when attacked by terrestrial versus aerial predators. The frogs fled away from the snake models (Median: 131°). In stark contrast, the frogs moved toward the bat models (Median: 27°); effectively undercutting the bat's flight path. Our results reveal that prey escape trajectories reflect the specificity of their predators' attacks. This study emphasizes the flexibility of strategies performed by prey to outcompete predators with diverse modes of attack. PMID:25874798

  17. Danger Comes from All Fronts: Predator-Dependent Escape Tactics of Túngara Frogs

    PubMed Central

    Bulbert, Matthew W.; Page, Rachel A.; Bernal, Ximena E.

    2015-01-01

    The escape response of an organism is generally its last line of defense against a predator. Because the effectiveness of an escape varies with the approach behaviour of the predator, it should be advantageous for prey to alter their escape trajectories depending on the mode of predator attack. To test this hypothesis we examined the escape responses of a single prey species, the ground-dwelling túngara frog (Engystomops pustulosus), to disparate predators approaching from different spatial planes: a terrestrial predator (snake) and an aerial predator (bat). Túngara frogs showed consistently distinct escape responses when attacked by terrestrial versus aerial predators. The frogs fled away from the snake models (Median: 131°). In stark contrast, the frogs moved toward the bat models (Median: 27°); effectively undercutting the bat’s flight path. Our results reveal that prey escape trajectories reflect the specificity of their predators’ attacks. This study emphasizes the flexibility of strategies performed by prey to outcompete predators with diverse modes of attack. PMID:25874798

  18. Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

    USGS Publications Warehouse

    Zydlewski, Joseph; Popescu, Viorel D.; Brodie, Bekka S.; Hunter, Malcom L.

    2012-01-01

    Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

  19. Characterization and steroidal regulation of gonadotropin beta subunits in the male leopard frog, Rana pipiens.

    PubMed

    Zhang, Lihong; Kessler, Ann E; Tsai, Pei-San

    2007-01-01

    In ranid frogs, the secretion of gonadotropins (GtHs), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), is potently regulated by gonadal steroids. To better understand the gonadal regulation of GtHs at the molecular level, we elucidated the full-length cDNA sequences of LH and FSH beta subunits from the leopard frog, Rana pipiens. The cDNAs for LHbeta and FSHbeta were 1084 and 667 bp in size excluding the poly (A) tail, and encoded proteins of 138 and 127 amino acids, respectively. Using reverse-transcription polymerase chain reaction (RT-PCR), the messages for LHbeta and FSHbeta were found in the pituitary, but not in the brain, heart, kidney, or the liver. Semi-quantitative RT-PCR revealed a significant elevation of FSHbeta, but not LHbeta, in mature male R. pipiens 21 days after gonadectomy (GDX). 17beta-estradiol implant for 21 days in GDX male frogs significantly suppressed the levels of both LHbeta and FSHbeta transcripts, whereas 5alpha-dihydrotestosterone implant suppressed only the latter. Together, these results laid the groundwork for investigating gonadal regulation of GtHbeta subunits in a ranid frog. Importantly, these data also revealed differential feedback effects of an androgen and an estrogen upon GtHbeta expression. PMID:16920113

  20. EVIDENCE FOR PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, ARIZONA

    EPA Science Inventory


    Remnant populations of leopard frogs exist within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada. These populations either represent the reportedly extinct taxa Rana onca or northern, disjunct R...