WorldWideScience

Sample records for frog odontophrynus cultripes

  1. Falcaustra sanjuanensis sp. nov. (Nematoda: Kathlaniidae) from Odontophrynus cf. barrioi (Anura: Cycloramphidae) from Argentina.

    Science.gov (United States)

    González, Cynthya E; Sanabria, Eduardo A; Quiroga, Lorena B

    2013-03-01

    Here, we describe a new kathlaniid nematode, Falcaustra sanjuanensis sp. nov., from the large intestine of Odontophrynus cf. barrioi (Anura: Cycloramphidae), from San Juan Province, Argentina. The new species belongs to the Falcaustra group that possesses a pseudosucker. It resembles F. andrias in the distribution pattern of caudal papillae (six precloacal, four adcloacal, 12 postcloacal, one unpaired median anterior to the cloaca) but differs from F. andrias in the following characters: the longer size of males and females (11.17-13.45 mm and 10.1-15.5 mm, respectively); the longer size and form of the gubernaculum (0.17-0.23 mm, triangular form); the arrangement of postcloacal papillae (three pairs on the ventral side, two pairs on the lateral side, one pair on the subventral side) and unpaired papilla anterior to the cloaca located on the protuberance. The species description is based on light microscopy and scanning electron microscopy (SEM). Falcaustra sanjuanensis sp. nov. represents the 12th Neotropical species assigned to the genus. Also, we added a key to Neotropical species of Falcaustra.

  2. Frog Statistics

    Science.gov (United States)

    Whole Frog Project and Virtual Frog Dissection Statistics wwwstats output for January 1 through duplicate or extraneous accesses. For example, in these statistics, while a POST requesting an image is as well. Note that this under-represents the bytes requested. Starting date for following statistics

  3. Frog eat frog: exploring variables influencing anurophagy

    OpenAIRE

    Measey, G. John; Vimercati, Giovanni; de Villiers, F. Andr?; 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 ...

  4. Frog eat frog: exploring variables influencing anurophagy.

    Science.gov (United States)

    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.

  5. Frog eat frog: exploring variables influencing anurophagy

    Directory of Open Access Journals (Sweden)

    G. John Measey

    2015-08-01

    Full Text Available 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.

  6. Courtship in Frogs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Courtship in Frogs Role of Acoustic Communication in Amphibian Courtship Behaviour. Debjani Roy. General Article Volume 1 Issue 12 December 1996 pp 39-48 ...

  7. Variación morfométrica intra e interespecífica entre poblaciones de Odontophrynus (Anura: Cycloramphidae del área central de Argentina Intraand inter-specific morphometric variation between Odontophrynus populations (Anura: Cycloramphidae of central Argentina

    Directory of Open Access Journals (Sweden)

    Pablo Raúl Grenat

    2012-12-01

    Full Text Available El análisis morfométrico ha servido como apoyo para explicar fenómenos ecológicos y evolutivos y para la clasificación de nuevas especies. Nosotros realizamos el análisis morfométrico de dos especies morfológicamente crípticas con el objeto de evaluar el grado de diferenciación intra e interespecífica. Se midieron 15 variables sobre 211 individuos pertenecientes a 18 localidades del centro de Argentina. Se encontró dimorfismo sexual en seis variables morfométricas en Odontophrynus cordobae y en tres variables en O. americanus. Se encontraron diferencias significativas entre especies en seis variables. El análisis discriminante incluyendo los individuos de todas las poblaciones relevadas para O. cordobae y O. americanus, mostró una clasificación positiva de los individuos dentro de su respectiva especie del 76.37%. En el análisis discriminante realizado con base en cuatro grupos (O. cordobae alopátrico y sintópico y O. americanus alopátrico y sintópico se obtuvo una reclasificación de los individuos dentro de cada grupo del 73.45%. Las diferencias morfométricas entre especies fueron mayores en sintopía. Los resultados se alejan de los resultados esperados bajo la hipótesis del desplazamiento de caracteres y podrían sugerir que los caracteres morfológicos externos no tendrían una influencia importante en el reconocimiento y elección de machos coespecíficos por parte de las hembrasMorphometric analyses are particularly important, and for many years they have supported evolutionary and ecological phenomena, and have been useful for the classification of new species, mainly to the lowest taxonomic levels. In order to assess the degree of sexual dimorphism, the intra-specific morphometric variation and the inter-specific morphological differences, we performed morphometric analyses of two morphologically cryptic species, Odontophrynus cordobae (diploid and O. americanus (tetraploid. For this, we measured 15 morphometric

  8. Courtship in Frogs

    Indian Academy of Sciences (India)

    well-defined physical characteristics and a clear biological meaning. ... men t most successfully were the frogs and toads (hereafter referred ... Sound Pressure Level (SPL) in decibels = 20 loglOPt/Pr where,. Pt is the .... R.erythraea (left) and mean spectrum and sonagram of the female ... and egg laying activities initiated. 5.

  9. Lithobates sylvaticus (wood frog)

    Science.gov (United States)

    Fuller, Pam

    2016-01-01

    A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

  10. Pemanfaatan kulit kodok (bull frog

    Directory of Open Access Journals (Sweden)

    Muchtar Lutfie

    1995-06-01

    Full Text Available The objective of this study was to measure the tensile strength and the elongation of finished leather made from Bull Frog skin, so that the utilization of that leather can be specified. The samples used were twenty pieces of wet salted Bull Frog skin from East Java which have been processed to finished leather using chromosal B. and Irgatan LV as the tanning agents. Laboratory tests shawed that the average tensile strength was 177,675 Kg/Cm2 and the average elongation was 89,9%. Based on those results, it can be concluded that Bull Frog leather was suitable for leather goods such as bag, wallet, etc. so it can be used as substitute for Glace leather.

  11. Guinea Worm in a Frog

    Centers for Disease Control (CDC) Podcasts

    2017-03-09

    Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

  12. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  13. CARE AND FEEDING OF FROGS

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2012-01-01

    '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, 'Blériot', appear consistent with a sinusoid of period ∼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 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 delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques. If t delay ib , then the libration amplitude damps to zero. In the case of Blériot, the frog resonance model can reproduce the observed libration period P lib ≅ 4 yr. However, our simple feedback prescription suggests that Blériot's t delay ∼ 0.01P 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.

  14. From frog integument to human skin: dermatological perspectives from frog skin biology

    NARCIS (Netherlands)

    Haslam, I.S.; Roubos, E.W.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

    2014-01-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

  15. Snoring puddle frog

    International Nuclear Information System (INIS)

    Lloyd, Mark Anthony

    2000-01-01

    Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society. Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate. The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved. The precise frequency of the croak of a particular species of frog; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes. 'The Recognition Concept of Species' (1985) is a monograph that has become something of a 'classic' in annals of evolutionary biology. Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system. Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives. Biological evolution has numerous links and parallels with the evolution of human cultures. Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable. Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan. We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl. Outsiders do not understand our language: terms like 'credit for fission products

  16. Eleutherodactylus frog introductions to Hawaii

    Science.gov (United States)

    Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

    1999-01-01

    As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

  17. Neuromuscular control of prey capture in frogs.

    OpenAIRE

    Nishikawa, K C

    1999-01-01

    While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions. (1) How do frog tongues differ biomechanically? (2) What anatomical and physiological differences are responsible? (3) How is biomechanics related to mechanisms of neuromuscular cont...

  18. Prey specialization and diet of frogs in Borneo

    OpenAIRE

    Ahlm, Kristoffer

    2015-01-01

    Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet. However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization. The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the 156 k...

  19. THE PROPELLER AND THE FROG

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2010-01-01

    '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 Bleriot in Saturn's A ring, our theory predicts a libration period of ∼4 years, similar to the ∼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.

  20. Birds and frogs in mathematics and physics

    Energy Technology Data Exchange (ETDEWEB)

    Dyson, Freeman J [Institute for Advanced Study, Princeton, NJ (United States)

    2010-11-15

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

  1. Hematophagous insects as vectors for frog trypanosomes.

    Science.gov (United States)

    Ramos, B; Urdaneta-Morales, S

    1977-12-01

    Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

  2. Birds and frogs in mathematics and physics

    International Nuclear Information System (INIS)

    Dyson, Freeman J

    2010-01-01

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

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

    Science.gov (United States)

    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.

  4. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  5. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  6. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

    OpenAIRE

    Gossling, J; Loesche, W J; Nace, G W

    1982-01-01

    The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs wer...

  7. Apomorphine effects on frog locomotor behavior

    OpenAIRE

    Chu, Joanne; Wilczynski, Walter

    2007-01-01

    The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology. DA is well known for its role in facilitating motor behaviors in mammals. We examined whether a similar role for DA exists in amphibians using the Northern Leopard Frog (Rana pipiens). We investigated the effects of the nonspecific DA agonist, apomorp...

  8. Vocal competition in male Xenopus laevis frogs

    OpenAIRE

    Tobias, Martha L.; Corke, Anna; Korsh, Jeremy; Yin, David; Kelley, Darcy B.

    2010-01-01

    Male Xenopus laevis frogs produce underwater advertisement calls that attract gravid females and suppress calling by male competitors. Here we explore whether groups of males establish vocal ranks and whether auditory cues alone suffice for vocal suppression. Tests of male–male pairs within assigned groups reveal linear vocal dominance relations, in which each male has a defined rank. Both the duration over which males interact, as well as the number of competitive opportunities, affect linea...

  9. Cellular mechanisms of nociception in the frog

    Czech Academy of Sciences Publication Activity Database

    Kuffler, D. P.; Lyfenko, Alla; Vyklický st., Ladislav; Vlachová, Viktorie

    2002-01-01

    Roč. 88, č. 4 (2002), s. 1843-1850 ISSN 0022-3077 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Grant - others:NATO(XX) Grant 977062 Institutional research plan: CEZ:AV0Z5011922 Keywords : cellular mechanisms of nociception * frog Subject RIV: FH - Neurology Impact factor: 3.743, year: 2002

  10. Biogeographic patterns of Colombian frogs and toads

    International Nuclear Information System (INIS)

    Lynch, John D.; Ruiz Carranza, Pedro M; Ardila Robayo, Maria Cristina

    1997-01-01

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

  11. Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria ...

    African Journals Online (AJOL)

    Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption. Data for the study were collected through questionnaire, ...

  12. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

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

    Science.gov (United States)

    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…

  14. Efficacy of ivermectin as an anthelmintic in leopard frogs.

    Science.gov (United States)

    Letcher, J; Glade, M

    1992-02-15

    Ivermectin administered cutaneously at dosages of 2 mg/kg of body weight eliminated nematode infections in leopard frogs. Three clinical trials were conducted. In the first trial, 5 groups of 11 frogs were given ivermectin IM at dosages of 0, 0.2, 0.4, 2, or 20 mg/kg. All frogs given ivermectin IM at dosages of 2.0 mg/kg or greater died. In trial 2, 44 frogs, allotted to 5 groups, were given ivermectin cutaneously at 0, 0.2, 2, or 20 mg/kg. Cutaneously administered ivermectin was not toxic at dosages up to 20 mg/kg. In trial 3, nematode infections were eliminated in all 10 frogs treated cutaneously with ivermectin at 2.0 mg/kg.

  15. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    OpenAIRE

    Edward C. Netherlands; Courtney A. Cook; Donnavan J.D. Kruger; Louis H. du Preez; Nico J. Smit

    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 extracell...

  16. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    Directory of Open Access Journals (Sweden)

    Dian Ratri Wulandari

    2013-04-01

    Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

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

    Science.gov (United States)

    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.

  18. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  19. Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands.

    Science.gov (United States)

    Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal; Gröne, Andrea; Kik, Marja J L

    2017-08-31

    Frog virus 3 was isolated from a strawberry poison frog ( Oophaga pumilio ) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op /2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the reference Frog virus 3 isolate. Copyright © 2017 Saucedo et al.

  20. Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal A; Gröne, Andrea; Kik, Marja J L

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  1. Complete genome sequence of frog virus 3, isolated from a strawberry poison frog (Oophaga pumilio) imported from nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; Beurden, van Steven J.; Suárez, Nicolás M.; Haenen, Olga L.M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kika, Marja J.L.

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  2. FROG: The Fast And Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  3. Metabolomic profiling of Green Frogs exposed to Mixed Pesticides

    Data.gov (United States)

    U.S. Environmental Protection Agency — GC/MS data from the metabolomic profiling of green frog livers after exposure to pesticides and their mixtures. This dataset is associated with the following...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Dian Zhang

    Full Text Available 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.

  6. Is chytridiomycosis driving Darwin's frogs to extinction?

    Directory of Open Access Journals (Sweden)

    Claudio Soto-Azat

    Full Text Available 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%; x(2 = 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.

  7. Female preferences for aposematic signal components in a polymorphic poison frog

    NARCIS (Netherlands)

    Maan, Martine E.; Cummings, Molly E.

    Aposematic signals may be subject to conflicting selective pressures from predators and conspecifics. We studied female preferences for different components of aposematic coloration in the polymorphic poison frog Oophaga pumilio across several phenotypically distinct populations. This frog shows

  8. Determination of age, longevity and age at reproduction of the frog ...

    Indian Academy of Sciences (India)

    Unknown

    separately in plastic bags and placed in 5 different aquaria. Each frog was anaesthetized (using anaesthetic ether), the body mass ... bone of each frog, were measured using an ocular .... One of the problems generally associated with skeleto-.

  9. Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

    DEFF Research Database (Denmark)

    Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

    1995-01-01

    Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

  10. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available 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

  11. Frogs Call at a Higher Pitch in Traffic Noise

    Directory of Open Access Journals (Sweden)

    Kirsten M. Parris

    2009-06-01

    Full Text Available Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii and the common eastern froglet (Crinia signifera. We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates.

  12. THE MOCHE BOTANICAL FROG (La rana botánica mochica)

    OpenAIRE

    Donna McClelland †

    2011-01-01

    Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog perform...

  13. Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

    Science.gov (United States)

    Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

    2005-01-01

    We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

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

    Science.gov (United States)

    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.

  15. Tourism and the Conservation of Critically Endangered Frogs

    Science.gov (United States)

    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

  16. Frog sound identification using extended k-nearest neighbor classifier

    Science.gov (United States)

    Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

    2017-09-01

    Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

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

    Directory of Open Access Journals (Sweden)

    Fábio P de Sá

    Full Text Available 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.

  18. Apomorphine effects on frog locomotor behavior.

    Science.gov (United States)

    Chu, Joanne; Wilczynski, Walter

    2007-05-16

    The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology. DA is well known for its role in facilitating motor behaviors in mammals. We examined whether a similar role for DA exists in amphibians using the Northern Leopard Frog (Rana pipiens). We investigated the effects of the nonspecific DA agonist, apomorphine (APO) on a complex motor task that included two distinct components known to be differentially modulated by DA in mammals: swimming and climbing. We demonstrated that a high single dose of APO (20 mg/kg, body weight) strongly increased the amount of time spent completing the motor task. Furthermore, we showed that although APO did not significantly alter several aspects of swimming behavior, two aspects of climbing behavior were disrupted. Both climbing speed and climbing ability were impaired by APO treatment. These results increase our understanding of DA function in amphibians and add to our understanding of structure-function homologies of dopamine function across vertebrate taxa.

  19. Distribution, structure and projections of the frog intracardiac neurons.

    Science.gov (United States)

    Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

    2012-05-21

    Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  1. Landscape genetics of high mountain frog metapopulations

    Science.gov (United States)

    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

  2. Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae

    Directory of Open Access Journals (Sweden)

    Duellman William E.

    1986-12-01

    Full Text Available Color polymorphism is common in many species of marsupial frogs.  Extreme cases of pattern polymorphism are documented in four species. In Amphignathodon guentheri, Castrotheca aureomaculata, G. qriswoldi, and G. helenae juveniles are known to have only one color morph, where as two or more patterns exist in adults. In these species, polymorphism apparently develops ontogenetically. El polimorfismo cromático es común a algunas especies de sapos marsupiales. Casos extremos del modelo de polimorfismo son evidentes en cuatro especies Amphignathodon guentheri, Gastrotheca aureomaculata, G. griswoldi, y G. helenae. En estas especies, se sabe que los juveniles tienen sólo un morfo de color; el polimorfismo, al parecer, se desarrolla ontogenéticamente.

  3. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  4. Speculations on colonizing success of the African clawed frog ...

    African Journals Online (AJOL)

    1991-12-12

    Dec 12, 1991 ... Robinson. Ann. Durban Mus. 1: 167-170. SMITH, J.L.B. 1961. Fishes of the family Apogonidae of the western Indian Ocean and the Red Sea.lchlhyol. .... J. Herp. 12: 391-396. BAIRD, T. 1983. Influence of social and predatory stimulus on the air-breathing behavior of the African clawed frog,. Xenopus laevis.

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

    Science.gov (United States)

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

    2015-08-21

    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.

  6. Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

    Science.gov (United States)

    Roelants, Kim; Bossuyt, Franky

    2005-02-01

    Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

  7. Choosing the safest route: frog orientation in an agricultural landscape

    NARCIS (Netherlands)

    Mazerolle, M.J.; Vos, C.C.

    2006-01-01

    Orientation is a key component to successful movements between habitats. We hypothesized that barren agricultural landscapes hinder the ability of frogs to orient and move between habitats. Specifically, we predicted that when presented with a choice between a short route through a hostile

  8. Frogs from the Leeward group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Brongersma, L.D.

    1948-01-01

    The present notes deal with a small collection of frogs that was made by Dr. P. WAGENAAR HUMMELINCK during his visits to the islands of the Leeward Group, Venezuela and Eastern Colombia. I have included in this study the specimens of Pleurodema brachyops (Cope) already present in the Rijksmuseum van

  9. Taxonomic variation in oviposition by tailed frogs (Aschaphus spp.).

    Science.gov (United States)

    Nancy E. Karraker; David S. Pilliod; Michael J. Adams; Evelyn L. Bull; Paul Stephen Corn; Lowell V. Diller; Linda A. Dupuis; Marc P. Hayes; Blake R. Hossack; Garth R. Hodgson; Erin J. Hyde; Kirk Lohman; Bradford R. Norman; Lisa M. Ollivier; Christopher A. Pearl; Charles R. Peterson

    2006-01-01

    Tailed frogs (Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular...

  10. A new grass frog from Namibia | Channing | African Zoology

    African Journals Online (AJOL)

    A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that ...

  11. Antifungal activity of epithelial secretions from selected frog species ...

    African Journals Online (AJOL)

    This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions ...

  12. Vectorcardiogram of the 'Man-Frog' | Skowron | South African ...

    African Journals Online (AJOL)

    Chest electrodes from a man and from a frog are connected simultaneously to an oscilloscope - the one to the vertical and the other to the horizontal plates - and the resulting display observed. It consists of a loop, the interpretation of which is discussed, and the conclusion is reached that the presently held vector theory ...

  13. Macro and Trace Element Accumulation in Edible Crabs and Frogs ...

    African Journals Online (AJOL)

    The tissue accumulation of five macroelements (Na, Mg, K, Ca, Fe) and twelve trace elements (Vd, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Pb) were assessed in the organs of the edible frogs; Xenopus laevis and Rana esculentus, and whole body of the crab, Callinestes caught from Alaro Stream Floodplain (Ibadan, ...

  14. Ranavirus in wild edible frogs Pelophylax kl. esculentus in Denmark

    DEFF Research Database (Denmark)

    Ariel, Ellen; Kielgast, Jos; Svart, Hans Erik

    2009-01-01

    interviewed by phone and 10 cases were examined on suspicion of diseaseinduced mortality. All samples were negative for Bd. Ranavirus was isolated from 2 samples of recently dead frogs collected during a mass mortality event in an artificial pond near Slagelse, Denmark. The identity of the virus was confirmed...

  15. Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

    DEFF Research Database (Denmark)

    Ariel, Ellen; Subramaniam, Kuttichantran; Imnoi, Kamonchai

    2017-01-01

    Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus) during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad r...

  16. Foraging behaviour in tadpoles of the bronze frog Rana temporalis ...

    Indian Academy of Sciences (India)

    Unknown

    The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to ... less of whether they are siblings or non-siblings in a group, which correlates well with ..... Sutherland W J and Parker G A 1992 The relationship between.

  17. Elastic modulus of tree frog adhesive toe pads.

    Science.gov (United States)

    Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

    2011-10-01

    Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

  18. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  19. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

    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.

  1. Measurement and Evaluation of Wear Frogs Switches ŽSR

    Directory of Open Access Journals (Sweden)

    Urda Ján

    2014-05-01

    Full Text Available This paper deals with the measurement and evaluation of wear frogs switches ZSR. One of the main problems is the oversize wear. The possibilities analysis of this problem is offered through a set of switches and monitoring of selected parameters. One of these parameters is also monitoring the vertical wear

  2. Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

    Science.gov (United States)

    Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

    2018-03-01

    Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

  3. COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

    Science.gov (United States)

    The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

  4. Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

    2018-01-01

    GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

  5. Sexual differences in prevalence of a new species of trypanosome infecting t?ngara frogs

    OpenAIRE

    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 trypa...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Effect of cattle exclosures on Columbia Spotted Frog abundance

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2018-01-01

    Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

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

    Science.gov (United States)

    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.

  9. The Genome of the Western Clawed Frog Xenopus tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. The rediscovered Hula painted frog is a living fossil.

    Science.gov (United States)

    Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig

    2013-01-01

    Amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. Because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. Here we report the rediscovery of the Hula painted frog, the first amphibian to have been declared extinct. We provide evidence that not only has this species survived undetected in its type locality for almost 60 years but also that it is a surviving member of an otherwise extinct genus of alytid frogs, Latonia, known only as fossils from Oligocene to Pleistocene in Europe. The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian.

  11. ESR analysis of irradiated frogs' legs and fishes

    International Nuclear Information System (INIS)

    Raffi, J.; Agnel, J.-P.; Evans, J.C.; Rowlands, C.C.; Lesgards, G.

    1989-01-01

    Electron spin resonance (ESR) spectral analysis of different parts (bones, scales, jaw, etc.) from ionized (irradiated) frozen frogs' legs and fishes (brown trout and sardine) were recorded. There is always present, after treatment, a signal due to the irradiation. ESR and ENDOR experiments lead us to assign it to h 1 centers from hydroxyapatite, as in the case of other irradiated meat bones. The use of ESR to prove whether one of these foods has been irradiated or not is discussed. (author)

  12. Vocalizations of primary forest frog species in the Central Amazon.

    OpenAIRE

    Zimmerman, Barbara L.; Bogart, James P.

    1984-01-01

    The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos National Park near Itaituba, the Reserva Ducke near Manaus, and the INPA-WWF reserves near Manaus. Structural and time parameters and sonographs of these calls including previously undescribed vocalization by 10 species are presented. Unlike open habitat species, several forest frong species characteriscally demonstrated one on more of the following temporal parameters: very low call rates, sporadic i...

  13. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    discrimination from background noise and heterospecific calls. However, we present here evidence that two anurans, Brachycephalus ephippium and B. pitanga, are insensitive to the sound of their own calls. Both species produce advertisement calls outside their hearing sensitivity range and their inner ears...... by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs....

  14. Reflex Marine celebrates 10. anniversary of FROG crew transfer device

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-07-15

    Reflex Marine developed the initial 3-person FROG crew transfer device in response to the main risks identified from incidents involving traditional rope baskets for personnel transfer: falling, collisions, hard landings, and immersion. To address these issues, the FROG was developed with 4-point harnesses, a protective shell, shock-absorbing landing feet, and self-righting capability. As a result of industry demand for a higher capacity transfer device, the company introduced 6- and 9-man versions of the FROG. The perceptions and reality of marine transfers have changed greatly over the past decade, from the design of the device to vessel specifications and increased focus on crane operations. Marine transfers offer a low-risk alternative to helicopter transfers. The TORO, a low-cost crew transfer capsule launched in February 2009, fits into a standard shipping container, providing significant logistical advantages. The TORO can carry 4 passengers, offer protection from side impacts and hard landings, and is buoyant and self-righting. Most of the units are being used by major oil and gas companies, but offshore wind turbines are an emerging source of demand for the crew transfer system. 3 figs.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. © 2016. Published by The Company of Biologists Ltd.

  17. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  18. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Nielsen, Robert

    2000-01-01

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  19. IgE antibodies of fish allergic patients cross-react with frog parvalbumin.

    Science.gov (United States)

    Hilger, C; Thill, L; Grigioni, F; Lehners, C; Falagiani, P; Ferrara, A; Romano, C; Stevens, W; Hentges, F

    2004-06-01

    The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin alpha has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin alpha and beta from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca(2+) depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with alpha parvalbumin and 11 of 12 reacted with beta parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens.

  20. An addition to the diversity of dendrobatid frogs in Venezuela: description of three new collared frogs (Anura: Dendrobatidae: Mannophryne

    Directory of Open Access Journals (Sweden)

    César Luis Barrio-Amorós

    2010-07-01

    Full Text Available Three new species of collared frogs of the genus Mannophryne are described from Venezuela. Two are newly discovered taxa from the Venezuelan Andes, whereas the third species, previously confused with M. trinitatis, is from the Caracas area in the Cordillera de la Costa. The call of the three new species and that of Mannophryne collaris are described. Taxonomic, zoogeographic, and conservation issues are discussed.

  1. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia) commercialized in France

    OpenAIRE

    Ohler, Annemarie; Nicolas, Violaine

    2017-01-01

    International audience; Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya ca...

  2. A frog's-eye view of the landscape : quantifying connectivity for fragmented amphibian populations

    NARCIS (Netherlands)

    Vos, C.C.

    1999-01-01

    The spatial habitat requirements are studied for two amphibian species: the tree frog ( Hyla arborea ) and the moor frog ( Rana arvalis ). Fragmentation, the destruction of suitable habitat, results in small fragments that are separated by

  3. Propulsive force calculations in swimming frogs I. A momentum-impulse approach

    NARCIS (Netherlands)

    Nauwelaerts, S; Stamhuis, EJ; Aerts, P

    Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

  4. Surveys for California red-legged frog and arroyo toad on the Los Padres National Forest

    Science.gov (United States)

    Valerie K. Hubbartt; Thomas G. Murphey

    2005-01-01

    Starting in the spring of 1999 through the fall of 2000, USDA Forest Service biologists have conducted surveys throughout the Los Padres National Forest for the federally-listed California red-legged frog (Rana aurora draytonii) and arroyo toad (Bufo californicus). Sites known to have frogs or toads present were monitored for...

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

    Science.gov (United States)

    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 (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.

  6. Bacterial flora on Cascades frogs in the Klamath Mountains of California

    Science.gov (United States)

    Karen Pope

    2013-01-01

    Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

  7. Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

    Science.gov (United States)

    Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

    2015-04-01

    We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

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

    Directory of Open Access Journals (Sweden)

    S D Biju

    Full Text Available 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.

  9. Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

    Science.gov (United States)

    Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

    2017-05-01

    Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Parasites of the mink frog (rana septentrionalis) from Minnesota, U.S.A.

    Science.gov (United States)

    Schotthoefer, Anna M.; Bolek, M.G.; Cole, Rebecca A.; Beasley, Val 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.

  12. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  13. Alternative leech vectors for frog and turtle trypanosomes.

    Science.gov (United States)

    Siddall, M E; Desser, S S

    1992-06-01

    Trypanosoma pipientis infections were achieved by exposing laboratory-raised bullfrog tadpoles (Rana catesbeiana) to the leech Desserobdella picta that had fed on infected frogs. Likewise, a laboratory-raised snapping turtle (Chelydra serpentina) was infected with Trypanosoma chrysemydis following exposure to infected Placobdella ornata. Transmission of the trypanosomes by these leeches constitutes new vector records for the parasites. The biology of D. picta and P. ornata suggests that they are more important in transmitting these flagellates than the species of leech previously reported as vectors.

  14. Taxonomy Icon Data: Japanese tree frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese tree frog Hyla japonica Chordata/Vertebrata/Amphibia Hyla_japonica_L.png Hyla_jap...onica_NL.png Hyla_japonica_S.png Hyla_japonica_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap...onica&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap

  15. Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Samantha Vertucci

    Full Text Available Southwest Australia (SWA is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals, and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly

  16. A Method for Mechanism Analysis of Frog Swimming Based on Motion Observation Experiments

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-05-01

    Full Text Available For understanding the mechanism of frog swimming under water and designing a frog-inspired swimming robot, kinematics of the frog body and trajectories of joints should be obtained. In this paper, an aquatic frog, Xenopus laevis, was chosen for analysis of swimming motions which were recorded by a high speed camera, and kinematic data were processed in a swimming data extraction platform. According to the shape features of the frog, we propose a method that the frog eyes are set as the natural data extraction markers for body motion, and kinematic data of joint trajectories are calculated by the contour points on the limbs. For the data processing, a pinhole camera model was built to transform the pixel coordinate system to world coordinate system, and the errors caused by the water refraction were analyzed and corrected. Finally, from the developed data extraction platform, the kinematic data for the analysis of swimming mechanism and design of frog-inspired robot were obtained.

  17. Poison frog colors are honest signals of toxicity, particularly for bird predators.

    Science.gov (United States)

    Maan, Martine E; Cummings, Molly E

    2012-01-01

    Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

  18. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834

    Directory of Open Access Journals (Sweden)

    Achariya Sailasuta

    2011-01-01

    Full Text Available One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834, were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140 were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia.

  19. Environmental and Host Effects on Skin Bacterial Community Composition in Panamanian Frogs

    Directory of Open Access Journals (Sweden)

    Brandon J. Varela

    2018-02-01

    Full Text Available Research on the amphibian skin microbiota has focused on identifying bacterial taxa that deter a pathogenic chytrid fungus, and on describing patterns of microbiota variation. However, it remains unclear how environmental variation affects amphibian skin bacterial communities, and whether the overall functional diversity of the amphibian skin microbiota is associated to such variation. We sampled skin microbial communities from one dendrobatoid frog species across an environmental gradient along the Panama Canal, and from three dendrobatoid frog species before and after the onset of the wet season in one site. We found frog skin microbial alpha diversity to be highest in frogs from sites with low soil pH, but no clear effect of the onset of the wet season. However, we found frog skin microbial community structure to be affected by soil pH and the onset of the wet season, which also resulted in a decrease in between-sample variation. Across the sampled frog species, bacterial functional groups changed with the onset of the wet season, with certain bacterial functional groups entirely disappearing and others differing in their relative abundances. In particular, we found the proportion of Bd-inhibitory bacteria to correlate with mean soil pH, and to increase in two of the frog species with the onset of the wet season. Taken together, our results suggest that structure and predicted function of amphibian bacterial skin communities may be influenced by environmental variables such as pH and precipitation, site effects, and host effects.

  20. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834)

    Science.gov (United States)

    Sailasuta, Achariya; Satetasit, Jetjun; Chutmongkonkul, Malinee

    2011-01-01

    One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834), were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140) were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs) surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia. PMID:21918731

  1. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    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

  2. Network thermodynamic approach compartmental analysis. Na+ transients in frog skin.

    Science.gov (United States)

    Mikulecky, D C; Huf, E G; Thomas, S R

    1979-01-01

    We introduce a general network thermodynamic method for compartmental analysis which uses a compartmental model of sodium flows through frog skin as an illustrative example (Huf and Howell, 1974a). We use network thermodynamics (Mikulecky et al., 1977b) to formulate the problem, and a circuit simulation program (ASTEC 2, SPICE2, or PCAP) for computation. In this way, the compartment concentrations and net fluxes between compartments are readily obtained for a set of experimental conditions involving a square-wave pulse of labeled sodium at the outer surface of the skin. Qualitative features of the influx at the outer surface correlate very well with those observed for the short circuit current under another similar set of conditions by Morel and LeBlanc (1975). In related work, the compartmental model is used as a basis for simulation of the short circuit current and sodium flows simultaneously using a two-port network (Mikulecky et al., 1977a, and Mikulecky et al., A network thermodynamic model for short circuit current transients in frog skin. Manuscript in preparation; Gary-Bobo et al., 1978). The network approach lends itself to computation of classic compartmental problems in a simple manner using circuit simulation programs (Chua and Lin, 1975), and it further extends the compartmental models to more complicated situations involving coupled flows and non-linearities such as concentration dependencies, chemical reaction kinetics, etc.

  3. LOCALIZATION OF PERMEABILITY BARRIERS IN THE FROG SKIN EPITHELIUM

    Science.gov (United States)

    Martinez-Palomo, A.; Erlij, D.; Bracho, H.

    1971-01-01

    Ruthenium red and colloidal lanthanum were used to determine the site of the structural barriers to diffusion within the intercellular spaces of frog skin epithelium. Electron micrographs show that occluding zonules located at the outer border of the stratum corneum and at the outer layer of the stratum granulosum are true tight junctions since they are impermeable to these tracers. Measurement of 140La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum. Examination of these skins with the electron microscope suggests that the compartment is localized between the external membrane of the cells at the outer layer of the s. granulosum and at the outermost surface of the skin. These observations and other findings described in the literature indicate that the site of the external high resistance barrier of the frog skin is localized at the outer border of the s. granulosum. PMID:4329611

  4. A novel 35 kDa frog liver acid metallophosphatase.

    Science.gov (United States)

    Szalewicz, A; Radomska, B; Strzelczyk, B; Kubicz, A

    1999-04-12

    The lower molecular weight (35 kDa) acid phosphatase from the frog (Rana esculenta) liver is a glycometalloenzyme susceptible to activation by reducing agents and displaying tartrate and fluoride resistance. Metal chelators (EDTA, 1,10-phenanthroline) inactivate the enzyme reversibly in a time- and temperature-dependent manner. The apoenzyme is reactivated by divalent transition metal cations, i. e. cobalt, zinc, ferrous, manganese, cadmium and nickel to 130%, 75%, 63%, 62%, 55% and 34% of the original activity, respectively. Magnesium, calcium, cupric and ferric ions were shown to be ineffective in this process. Metal analysis by the emission spectrometry method (inductively coupled plasma-atomic emission spectrometry) revealed the presence of zinc, iron and magnesium. The time course of the apoenzyme reactivation, the stabilization effect and the relatively high resistance to oxidizing conditions indicate that the zinc ion is crucial for the enzyme activity. The presence of iron was additionally confirmed by the visible absorption spectrum of the enzyme with a shoulder at 417 nm and by the electron paramagnetic resonance line of high spin iron(III) with geff of 2.4. The active center containing only zinc or both zinc and iron ions is proposed. The frog liver lower molecular weight acid phosphatase is a novel metallophosphatase of lower vertebrate origin, distinct from the mammalian tartrate-resistant, purple acid phosphatases.

  5. Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia

    Directory of Open Access Journals (Sweden)

    Leandro Talione Sabagh

    2012-02-01

    Full Text Available We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae and Leptodactylus andreae (Leptodactylidae in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.

  6. First report of Hepatozoon sp. in the Oregon spotted frog, Rana pretiosa.

    Science.gov (United States)

    Stenberg, Patricia L; Bowerman, William J

    2010-07-01

    From 2005 through 2008, we screened 650 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon, USA, for hemoparasites. A Hepatozoon sp., not previously reported in R. pretiosa, was found in one population of frogs, mostly as intracellular gamonts at a prevalence of 10.5% with parasitemias ranging from 0.02% to greater than 42% of erythrocytes within individual frogs. Intra-and extracellular merozoites were present, but rare. A potential vector, the mosquito Culex boharti, was common throughout the habitat of the population carrying Hepatozoon sp.

  7. The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

    Science.gov (United States)

    Del Pino, Eugenia M

    2018-01-03

    The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Species Profile: Gopher Frog (Rana capito spp.) on Military Installations in the Southeastern United States

    National Research Council Canada - National Science Library

    Palis, John

    1997-01-01

    ....' Gopher frogs inhabit xeric upland pine communities of the Southeastern Coastal Plain from the southern half of the North Carolina coastal plain to southern Florida and westward to eastern Louisiana...

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

    Science.gov (United States)

    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.

  10. Further Development and Validation of the Frog Embryo Teratogenesis Assay - Xenopus (FETAX). Phase III

    National Research Council Canada - National Science Library

    Bantle, John

    1996-01-01

    This interlaboratory study of the Frog Embryo Teratogenesis Assay (FETAX) was undertaken in order to assess the repeatability and reliability of data collected under the guide published by the American Society for Testing and Materials...

  11. Design and Evaluation of a Digital Flight Control System for the FROG Unmanned Aerial Vehicle

    National Research Council Canada - National Science Library

    Flood, Christopher

    2001-01-01

    .... This autopilot imposed significant limitations on the responsiveness of the FROG. This project developed and tested an off board digital flight control system for use in lieu of the previous electromechanical device...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

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

  16. Effects of X-irradiation on some aspects of protein metabolism in the frog, Rana hexadactyla

    International Nuclear Information System (INIS)

    Rajarami Reddy, G.; Sasira Babu, K.

    1980-01-01

    Changes in the level of total proteins and protease in brain, muscle and liver tissues of normal and X-irradiated frogs were determined. Low doses of radiation produced an increment in protein level while high doses produced decrement. However, protease activity at all doses exhibited an elevatory trend. Exposure of frogs to lethal doses resulted in increased protease activity and decreased protein content during post-irradiation periods. The results are discussed on the basis of protein destruction and lysosomal damage. (auth.)

  17. Interference of a short-chain phospholipid with ion transport pathways in frog skin

    DEFF Research Database (Denmark)

    Unmack, M A; Frederiksen, O; Willumsen, N J

    1997-01-01

    The effects of mucosal application of the short-chain phospholipid didecanoyl-L-alpha-phosphatidylcholine (DDPC; with two saturated 10-carbon acyl chains) on active Na+ transport and transepithelial conductance (G) in the frog skin (Rana temporaria) were investigated. Active Na+ transport...... of the frog skin epithelium and opens a paracellular tight junction pathway. Both effects may be caused by incorporation of DDPC in the apical cell membrane....

  18. Pecular Features of Hematopoiesis in the Liver of Mature and Immature Green Frogs (Pelophylax Esculentus Complex

    Directory of Open Access Journals (Sweden)

    Akulenko N. M.

    2016-12-01

    Full Text Available The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex. Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.

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

    Directory of Open Access Journals (Sweden)

    Ximena E. Bernal

    2016-04-01

    Full Text Available 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.

  20. Glycogen accumulation in normal and irradiated minced muscle autografts on frog gastrocnemius

    International Nuclear Information System (INIS)

    Malhotra, R.K.; Kaul, R.; Malhotra, N.

    1989-01-01

    Alterations induced in glycogen content and phosphorylase activity have been studied in normal and irradiated minced muscle autografts on frog gastrocnemius at days 1, 3, 5, 7, 10, 15 and 30 postgrafting. The changes observed in the glycogen content and phosphorylase activity conform to the degeneration and regeneration phases of muscle repair. An attempt has been made to explain the altered glycogen utilizing capacities of the frog skeletal muscle during its repair and regeneration. (author)

  1. How minute sooglossid frogs hear without a middle ear.

    Science.gov (United States)

    Boistel, Renaud; Aubin, Thierry; Cloetens, Peter; Peyrin, Françoise; Scotti, Thierry; Herzog, Philippe; Gerlach, Justin; Pollet, Nicolas; Aubry, Jean-François

    2013-09-17

    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.

  2. Endocrine control of active sodium transport across frog skin

    International Nuclear Information System (INIS)

    Maetz, J.

    1959-01-01

    I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [fr

  3. Origin of invasive Florida frogs traced to Cuba

    Science.gov (United States)

    Heinicke, Matthew P.; Diaz, Luis M.; Hedges, S. Blair

    2011-01-01

    Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent. PMID:21270024

  4. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  5. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve

    International Nuclear Information System (INIS)

    Salem, A.; Hafedh, A.; Mohsen, S.

    2004-01-01

    Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve. Design: The combined effect of magnetic field and cadmium (1.5mg/kg; in lymphatic sac) were studied in frog sciatic nerves (Rana Esculenta). Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma (ICP) ionic composition. Setting: Frogs (Rana Esculenta) were reared in swimming-pool (Faculte des Sciences de Bizerte, Tunisia). Frogs were cared for under the Tunisian Code of Practice for the Care and Use of Animals for Scientific purpose and the Experimental Protocols were approved by the Ethics Committee. Subjects: Treated and control groups (n=6) weighing 50-100g at the time of experiments were housed in the same condition three weeks before the beginning of the experiments. Results: Acute exposure to magnetic field increased significantly the calcium (+298%, p<0.05) and iron (+50%, p<0.05) contents of frog sciatic nerve, whereas magnesium and copper contents remained unchanged. The association between magnetic field and cadmium, induced marked increase of calcium (+360%, p<0.05), whereas magnesium content remained stable. Conclusions: Magnetic field exposure alters the ionic composition in the frog sciatic nerve, especially calcium and iron. Magnetic field magnifies the effect of cadmium on calcium homeostasis. (author)

  6. Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

    Science.gov (United States)

    Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

    2012-04-01

    Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

  7. The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

    Directory of Open Access Journals (Sweden)

    Marcio Mageski

    2015-10-01

    Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

  8. Acute Toxicity of a Heavy Metal Cadmium to an Anuran, the Indian Skipper Frog Rana cyanophlyctis

    Directory of Open Access Journals (Sweden)

    Ajai Kumar Srivastav

    2016-08-01

    Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L. At different exposure periods (24, 48, 72 and 96 h, the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of cadmium chloride for the frog R. cyanophlyctis at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.

  9. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

    Science.gov (United States)

    Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

    2008-02-01

    We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  10. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí, Espírito Santo (Praia das Neves and Setiba and Bahia (Prado and Trancoso. We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species, followed by Grussaí and Trancoso (eight species in each. The commonest species in the restingas was Scinax alter (found in eight restingas, followed by Aparasphenodon brunoi (seven areas. Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007. Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  11. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Science.gov (United States)

    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

  12. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Edward C. Netherlands

    2015-04-01

    Full Text Available 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.

  13. Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

    Science.gov (United States)

    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. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

    Science.gov (United States)

    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 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.

  15. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Directory of Open Access Journals (Sweden)

    Corinna E Dreher

    Full Text Available 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

  16. Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

    Science.gov (United States)

    Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

    2016-04-01

    Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    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. © 2015 SETAC.

  18. Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

    Directory of Open Access Journals (Sweden)

    Mark-Oliver Rödel

    Full Text Available 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.

  19. THE MOCHE BOTANICAL FROG (La rana botánica mochica

    Directory of Open Access Journals (Sweden)

    Donna McClelland †

    2011-06-01

    Full Text Available Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog was associated with agriculture. ESPAÑOL: El arte de la cultura mochica de la costa norte del Perú presenta plantas y animales mostrando rasgos sobrenaturales. Uno de los animales es una rana con elementos felinos y asociada con tubérculos, ramas y plantas de yuca. La Rana Botánica probablemente tiene su origen en Leptodactylus pentadactylus, una rana carnívora de la selva amazónica. La Rana Botánica copula con felinos y, en vasijas pintadas con líneas finas o con escenarios representados en bajorrelieve, toma parte en ceremonias involucrando a otros animales y cosechas domésticas. Parece ser que la Rana Botánica era un ser sobrenatural asociado con la agricultura.

  20. Evaluation of use of tiletamine/zolazepam for anesthesia of bullfrogs and leopard frogs.

    Science.gov (United States)

    Letcher, J; Durante, R

    1995-07-01

    Use of tiletamine hydrochloride and zolazepam hydrochloride (1:1 fixed ratio combination) as an anesthetic agent in 2 anuran species was studied. A dosage of 5 mg/kg of body weight, administered IM, resulted in variable weak tranquilization. Intramuscular administration at dosages of 10 and 20 mg/kg induced variable states of tranquilization or anesthesia in leopard frogs (Rana pipiens) and bullfrogs (R catesbeiana). The dosages of 50 mg/kg induced anesthesia with greater consistency than lower dosages in bullfrogs, but resulted in mortalities. The same dosage was uniformly fatal in leopard frogs. Neither gross nor histologic lesions were identified in the frogs that died. Depth and duration of anesthesia was dosage related. At the 20 and 50 mg/kg dosages, leopard frogs attained a greater depth of anesthesia and remained anesthetized for a significantly greater duration than did bullfrogs; however, at the 5 and 10 mg/kg dosages, bullfrogs developed greater tranquilization for longer periods than did leopard frogs. Results of this study revealed profound intraspecies variation in depth and duration of effect of tiletamine/zolazepam; therefore, the drug does not appear to be a suitable injectable anesthetic in anurans.

  1. Citizen Science Program Shows Urban Areas Have Lower Occurrence of Frog Species, but Not Accelerated Declines.

    Directory of Open Access Journals (Sweden)

    Martin J Westgate

    Full Text Available 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.

  2. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Directory of Open Access Journals (Sweden)

    Fan Jizhuang

    2017-04-01

    Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

  3. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats. Keywords: Climate change, Functionality, Microhabitat, Refuge, Ectotherm, Precipitation

  4. Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

    Science.gov (United States)

    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.

  5. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    Science.gov (United States)

    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.

  6. Chiricahua leopard frog status in the Galiuro Mountains, Arizona, with a monitoring framework for the species' entire range

    Science.gov (United States)

    Lawrence L. C. Jones; Michael J. Sredl

    2005-01-01

    The Chiricahua leopard frog (Rana chiricahuensis) was historically widespread in suitable habitat throughout its range. Reports of recent population declines led to inventories of Chiricahua leopard frog localities. Surveys reported here establish a new baseline of occurrence in the Galiuros: only two of 21 historical localities were found to be...

  7. Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

    International Nuclear Information System (INIS)

    Sang, F.C.; Hugh-Jones, M.E.; Hagstad, H.V.

    1987-01-01

    Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60 Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

  8. Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary.

    Science.gov (United States)

    Feng, Yan-Jie; Blackburn, David C; Liang, Dan; Hillis, David M; Wake, David B; Cannatella, David C; Zhang, Peng

    2017-07-18

    Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.

  9. Environmental constraints and call evolution in torrent-dwelling frogs.

    Science.gov (United States)

    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. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  10. Synthesis of nanoparticles with frog foam nest proteins

    International Nuclear Information System (INIS)

    Choi, Hyo-Jick; Ebersbacher, Charles F.; Myung, Nosang V.; Montemagno, Carlo D.

    2012-01-01

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water–oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8–10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  11. Synthesis of nanoparticles with frog foam nest proteins

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyo-Jick, E-mail: choihc@ucmail.uc.edu; Ebersbacher, Charles F. [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States); Myung, Nosang V. [University of California, Riverside, Department of Chemical and Environmental Engineering (United States); Montemagno, Carlo D., E-mail: montemcd@ucmail.uc.edu [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States)

    2012-09-15

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water-oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8-10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  12. Synthesis of nanoparticles with frog foam nest proteins

    Science.gov (United States)

    Choi, Hyo-Jick; Ebersbacher, Charles F.; Myung, Nosang V.; Montemagno, Carlo D.

    2012-09-01

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water-oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8-10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  13. Birds and frogs selected papers, 1990-2014

    CERN Document Server

    Dyson, Freeman J

    2015-01-01

    This book is a sequel to the volume of selected papers of Dyson up to 1990 that was published by the American Mathematical Society in 1996. The present edition comprises a collection of the most interesting writings of Freeman Dyson, all personally selected by the author, from the period 1990–2014. The five sections start off with an Introduction, followed by Talks about Science, Memoirs, Politics and History, and some Technical Papers. The most noteworthy is a lecture entitled Birds and Frogs to the American Mathematical Society that describes two kinds of mathematicians with examples from real life. Other invaluable contributions include an important tribute to C. N. Yang written for his retirement banquet at Stony Brook University, as well as a historical account of the Operational Research at RAF Bomber Command in World War II provocatively titled A Failure of Intelligence. The final section carries the open-ended question of whether any conceivable experiment could detect single gravitons to provide d...

  14. Habitat selection, movement patterns, and hazards encountered by northern leopard frogs (Lithobates pipiens) in an agricultural landscape

    Science.gov (United States)

    Knutson, Melinda G.; Herner-Thogmartin, Jennifer H.; Thogmartin, Wayne E.; Kapfer, Joshua M.; Nelson, John

    2018-01-01

    Telemetry data for 59 Northern Leopard Frogs (Lithobates pipiens) breeding in ponds in Houston and Winona Counties, MN; 2001-2002. Agricultural intensification is causing declines in many wildlife species, including Northern Leopard Frogs (Lithobates pipiens). Specific information about frog movements, habitat selection, and sources of mortality can be used to inform conservation-focused land management and acquisition. We studied Northern Leopard Frogs in southeastern Minnesota, part of the Driftless Area ecoregion, characterized by hills and valleys and a mix of agriculture, forests, small towns and farmsteads. In this area, small farm ponds, originally built to control soil erosion are used by the species for breeding and wintering in addition to riparian wetlands. But, this agricultural landscape may be hazardous for frogs moving between breeding, feeding, and wintering habitats. We surgically implanted transmitters into the peritoneal cavity of 59 Northern Leopard Frogs and tracked them from May to October 2001-2002. The total distance traveled by radio-tagged frogs ranged from 12 to 3316 m, the 95% home range averaged 5.3 ± 1.2 (SE) ha, and the 50% core area averaged 1.05 ± 0.3 (SE) ha. As expected, Northern Leopard Frogs selected wetlands over all other land cover classes and row crops were generally avoided at all levels of selection. Only a few tracked frogs were successful at dispersing (n = 6). Most frogs attempting to disperse (n =31) ended up missing (n = 14), died due to mowing (n = 8), or were recorded as transmitter failure (n = 2) or unknown mortalities (n = 1). For the conservation of Northern Leopard Frogs in this agricultural setting, we must consider both the aquatic and the terrestrial needs of this species. Conservation agencies that restore, manage, and acquire wetlands should consider the hazards posed by land uses adjacent to frog breeding and wintering sites and plan for movement corridors between these locations. For example

  15. A success model and implementation on examining teacher’s attitude in using frog virtual learning environment

    Directory of Open Access Journals (Sweden)

    Wan Rozaini Sheik Osman

    2017-12-01

    Full Text Available The Frog Virtual Learning Environment (Frog VLE together with school administrators, teachers, students and parents has formed the concept of a virtual community within the school environment. The research uses a qualitative approach that involves interviewing four selected teachers in a primary school located in the district of Baling/ Sik, Kedah. The study employs a structured questionnaire as an interview protocol instrument. The questionnaires were also distributed to sixteen other teachers to compare the responses. The findings showed that teachers were using Frog VLE application and it helps in teaching and learning. Frog VLE also motivates teachers to teach better. However, not all teachers are comfortable using it because there are many obstacles and constraints that teachers face when applying them. The analysis of result from the teacher’s attitude indicated that there was an important relationship between the teacher’s basic knowledge of ICT and the skills in accessing the Frog VLE.

  16. FROG ASSEMBLAGE ASSOCIATED WITH BROMELIADS IN A SANDY COASTAL PLAIN IN THE STATE OF ESPÍRITO SANTO, SOUTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    MARCIO MARQUES MAGESKI

    Full Text Available ABSTRACT Amphibians may use bromeliads for reproduction (i.e., bromeligenous species or only for refuge and foraging (i.e., bromelicolous species. The partition of bromeliad resources is essential to maintain the coexistence of the associated assemblages. We sampled 913 bromeliads in a sandy coastal plain (i.e., restinga habitat in southeastern Brazil and found 234 frogs belonging to seven species. One of the frog species was bromeligenous and the other six were facultative bromelicolous. The bromeliads of the genus Aechmea were the most frequently used by frogs. The low degree of frog occupancy of bromeliads (26% suggests habitat segregation. Our study highlights the importance of maintenance of bromeliad species for conservation of the associated frog assemblages.

  17. Columbia spotted frog (Rana luteiventris) in southeastern Oregon: A survey of historical localities, 2009

    Science.gov (United States)

    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.

  18. Main alkaloids from the Brazilian dendrobatidae frog Epipedobates flavopictus: pumiliotoxin 251D, histrionicotoxin and decahydroquinolines.

    Science.gov (United States)

    Mortari, Márcia Renata; Schwartz, Elisabeth N Ferroni; Schwartz, Carlos Alberto; Pires, Osmindo Rodrigues; Santos, Marcello Moreira; Bloch, Carlos; Sebben, Antonio

    2004-03-01

    Epipedobates flavopictus, Dendrobatidae, is a small aposematic frog found in Brazilian Cerrado bioma. In the present work, we isolated and characterized chemically the most abundant alkaloids present in the cutaneous extract of E. flavopictus. The specimens were collected in Pirenópolis (Goiás, Brazil), their skins were removed and extracted with methanol, and submitted to purification by HPLC and identification by gas chromatography and mass spectrometry. Pumiliotoxin 251D, histrionicotoxin 285Da and two decahydroquinolines, 219A and 243A, were identified. The pumiliotoxin 251D was tested on isolated frog sciatic nerve and on isolated guinea pig ileum muscle. The pumiliotoxin 251D slightly reduced the action potentials amplitude of frog sciatic nerve. The crude skin extract of E. flavopictus and the pumiliotoxin 251D produced rhythmic contractions and increased the muscular tension on isolated guinea pig ileum.

  19. Field guide to malformations of frogs and toads: with radiographic interpretations

    Science.gov (United States)

    Meteyer, Carol U.

    2000-01-01

    In 1995, students found numerous malformed frogs on a field trip to a Minnesota pond. Since that time, reports of malformed frogs have increased dramatically. Malformed frogs have now been reported in 44 states in 38 species of frogs, and 19 species of toads. Estimates as high as 60% of the newly metamorphosed frog populations have had malformations at some ponds (NARCAM, ’99). The wide geographic distribution of malformed frogs and the variety of malformations are a concern to resource managers, research scientists and public health officials. The potential for malformations to serve as a signal of ecosystem disruption, and the affect this potential disruption might have on other organisms that share those ecosystems, has not been resolved. Malformations represent an error that occurred early in development. The event that caused the developmental error is temporally distant from the malformation we see in the fully developed animal. Knowledge of normal developmental principles is necessary to design thoughtful investigations that will define the events involved in abnormal development in wild frog populations.Development begins at the time an egg is fertilized and progresses by chemical communication between cells and cell layers. This communication is programmed through gene expression. Malformations represent primary errors in development, errors in chemical communication or translation of genetic information. Deformations arise later in development and usually result from the influence of mechanical factors (such as amputation) that alter shape or anatomy of a structure that has developed normally. The occurrence and the type of malformations are influenced by the type of error or insult as well as the timing of the error (the developmental stage at which the error occurred). The appearance of the malformation can therefore provide clues that suggest when the error may have occurred. If the malformation is an incomplete organ, such as an incomplete limb, the

  20. Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

    Science.gov (United States)

    Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

    2011-06-23

    Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

  1. Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

    Directory of Open Access Journals (Sweden)

    Todd G. Smith

    2012-04-01

    Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

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

    Science.gov (United States)

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

    2013-12-01

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

  3. The Australasian frog family Ceratobatrachidae in China, Myanmar and Thailand: discovery of a new Himalayan forest frog clade

    Science.gov (United States)

    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

  4. The potential effects of climate change on the status of Seychelles frogs (Anura: Sooglossidae

    Directory of Open Access Journals (Sweden)

    J. Gerlach

    2011-11-01

    Full Text Available The status of the Seychelles frogs of the family Sooglossidae was investigated, using monitoring data from 1993-2010, climate data from 1998-2010 and studies of populations and local climate effects. Climate monitoring at each plot covered rainfall and temperature, with leaf wetness and soil moisture being monitored additionally at one site. Analysis of the data and ecological modelling of the distribution identify geographical patterns in climate which explain the present distribution of the different sooglossid species. In addition it identifies a drying trend in the first quarter of the year which corresponds to frog population declines in mid-altitude forests. This is interpreted as evidence of an ongoing deterioration in the suitability of habitats for the frogs, with declines recorded in areas of marginal suitability. By extension it is assumed that currently optimal frog habitat is also undergoing a decline in suitability, due to early year decreases in moisture. Projected changes in climate were used to predict changes in ranges of the sooglossids over the next 90 years. This predicts significant declines, with the possible extinction of the palm frog Sooglossus pipilodryas by 2100. Accordingly all four sooglossid species should be categorised as Endangered, rather than their current status of Vulnerable. Captive assurance colonies have not been successfully established to date. Captive groups have been maintained with a high degree of success but breeding has not been recorded so far. Further work needed for the conservation of the frogs is outlined: development of a reliable method of monitoring the cryptic S. thomasseti and development of captive breeding techniques.

  5. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    Science.gov (United States)

    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 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

  6. Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

    Science.gov (United States)

    Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

    2008-09-01

    Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

  7. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

    Science.gov (United States)

    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

  8. Diversity within diversity: Parasite species richness in poison frogs assessed by transcriptomics.

    Science.gov (United States)

    Santos, Juan C; Tarvin, Rebecca D; O'Connell, Lauren A; Blackburn, David C; Coloma, Luis A

    2018-08-01

    Symbionts (e.g., endoparasites and commensals) play an integral role in their host's ecology, yet in many cases their diversity is likely underestimated. Although endoparasites are traditionally characterized using morphology, sequences of conserved genes, and shotgun metagenomics, host transcriptomes constitute an underused resource to identify these organisms' diversity. By isolating non-host transcripts from host transcriptomes, individual host tissues can now simultaneously reveal their endoparasite species richness (i.e., number of different taxa) and provide insights into parasite gene expression. These approaches can be used in host taxa whose endoparasites are mostly unknown, such as those of tropical amphibians. Here, we focus on the poison frogs (Dendrobatidae) as hosts, which are a Neotropical clade known for their bright coloration and defensive alkaloids. These toxins are an effective protection against vertebrate predators (e.g., snakes and birds), bacteria, and skin-biting ectoparasites (e.g., mosquitoes); however, little is known about their deterrence against eukaryotic endoparasites. With de novo transcriptomes of dendrobatids, we developed a bioinformatics pipeline for endoparasite identification that uses host annotated RNA-seq data and set of a priori parasite taxonomic terms, which are used to mine for specific endoparasites. We found a large community of helminths and protozoans that were mostly restricted to the digestive tract and a few systemic parasites (e.g., Trypanosoma). Contrary to our expectations, all dendrobatid frogs regardless of the presence of alkaloid defenses have endoparasites, with their highest species richness located in the frog digestive tract. Some of these organisms (e.g., roundworms) might prove to be generalists, as they were not found to be co-diversifying with their frog hosts. We propose that endoparasites may escape poison frogs' chemical defenses by colonizing tissues with fewer alkaloids than the frog's skin

  9. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

    Science.gov (United States)

    Smalling, Kelly L.; Reeves, Rebecca; Muths, Erin L.; Vandever, Mark W.; Battaglin, William A.; Hladik, Michelle; 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

  10. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    International Nuclear Information System (INIS)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu; Jia Xiuying

    2012-01-01

    Highlights: ► Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. ► Cd can result in oxidative stress in the frog testes. ► Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. ► Cd can cause apoptosis in the testes of male R. limnocharis. ► Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose–effect relationship. Moreover, the same dosages of Cd 2+ solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5–7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

  11. The redesigned Forensic Research/Reference on Genetics-knowledge base, FROG-kb.

    Science.gov (United States)

    Kidd, Kenneth K; Soundararajan, Usha; Rajeevan, Haseena; Pakstis, Andrew J; Moore, Katherine N; Ropero-Miller, Jeri D

    2018-03-01

    The Forensic Resource/Reference on Genetics-knowledge base (FROG-kb) web site was introduced in 2011 and in the five years since the previous publication ongoing research into how the database can better serve forensics has resulted in extensive redesign of the database interface and functionality. Originally designed as a prototype to support forensic use of single nucleotide polymorphisms (SNPs), FROG-kb provides a freely accessible web interface that facilitates forensic practice and can be useful for teaching and research. Based on knowledge gained through its use, the web interface has been redesigned for easier navigation through the multiple components. The site also has functional enhancements, extensive new documentation, and new reference panels of SNPs with new curated data. FROG-kb focuses on single nucleotide polymorphisms (SNPs) and provides reference population data for several published panels of individual identification SNPs (IISNPs) and several published panels of ancestry inference SNPs (AISNPs). For each of the various marker panels with reference population data, FROG-kb calculates random match probabilities (RMP) and relative likelihoods of ancestry for a user-entered genotype profile (either completely or partially specified). Example genotype profiles are available and the User's Manual presents interpretation guidelines for the calculations. The extensive documentation along with ongoing updates makes FROG-kb a comprehensive tool in facilitating use of SNPs in forensic practice and education. An overview of the new FROG-kb with examples and material explaining the results of its use are presented here. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb.

    Science.gov (United States)

    Rajeevan, Haseena; Soundararajan, Usha; Pakstis, Andrew J; Kidd, Kenneth K

    2012-09-01

    Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and functionalities that will be most helpful

  13. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob

    2014-01-01

    by individuals to generate their observed population behaviour. A number of existing agent-modelling frameworks are considered, but none have the ability to handle large numbers of time-dependent event-generating agents; hence the construction of a new tool, RANA. The calling behaviour of the Puerto Rican Tree...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

  14. Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

    Science.gov (United States)

    Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

    2017-10-01

    Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against

  15. Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    Dieni, Christopher A; Storey, Kenneth B

    2008-04-22

    The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65-70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to approximately 1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg.ATP and Mg.ADP and inhibited by Mg.GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5 degrees C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

  16. Food Habits of the Endemic Long Legged Wood Frog, Rana Pseudodalmatina (Amphibia, Ranidae, in Northern Iran

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    Najibzadeh M.

    2016-08-01

    Full Text Available Iranian long legged wood frog, Rana pseudodalmatina Eiselt & Schmidtler, 1971 is a brown frog species endemic to the Hyrcanian forest. The objective of the present study is to collect detailed information on the feeding habits of 44 specimens of this species (24 ♂, 20 ♀ by analyzing the stomach contents of individuals from 10 populations inhabiting range. The food habit of R. pseudodalmatina generally varies by the availability of surrounding prey items, and it is a foraging predator, the food of which consists largely of Coleoptera (mainly Carabidae, Dytiscidae and Haliplidae, Diptera (Muscidae and Hymenoptera (Formicidae, and no difference was found between females and males in the stomach content.

  17. Helminth parasites of the levantine frog (Pelophylax bedriagae Camerano, 1882 from the western part of Turkey

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    Demır S.

    2015-02-01

    Full Text Available Fifty-four Pelophylax bedriagae (Levantine Frog from Turkey (İzmir and Manisa Provinces were examined for helminth parasites. The frogs were collected between 2012 and 2014 years. Eight species of helminth parasites were recorded: 3 species of Nematoda (Rhabdias bufonis, Cosmocerca ornata, Oswaldocruzia filiformis, 3 species of Digenea (Diplodiscus subclavatus, Haematoloechus bre-viansa, Gorgoderina vitelliloba, 1 species of Acanthocephala (Acanthocephalus ranae and 1 species of Hirudinea (Hirudo medicinalis. Pelophylax bedriagae is a new host record for these parasite species.

  18. Histamine H1 receptors are expressed in mouse and frog semicircular canal sensory epithelia.

    Science.gov (United States)

    Botta, Laura; Tritto, Simona; Perin, Paola; Laforenza, Umberto; Gastaldi, Giulia; Zampini, Valeria; Zucca, Gianpiero; Valli, Stefano; Masetto, Sergio; Valli, Paolo

    2008-03-05

    Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. Their site and mechanism of action, however, are still poorly understood. To increase our knowledge of the histaminergic system in the vestibular organs, we have investigated the expression of H1 and H3 histamine receptors in the frog and mouse semicircular canal sensory epithelia. Analysis was performed by mRNA reverse transcriptase-PCR, immunoblotting and immunocytochemistry experiments. Our data show that both frog and mouse vestibular epithelia express H1 receptors. Conversely no clear evidence for H3 receptors expression was found.

  19. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  20. A new Gephyromantis (Phylacomantis frog species from the pinnacle karst of Bemaraha, western Madagascar

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    Angelica Crottini

    2011-02-01

    Full Text Available We describe a new mantellid frog of the subfamily Mantellinae from the karstic Bemaraha Plateau, western Madagascar. The new species belongs to the genus Gephyromantis, subgenus Phylacomantis, which previously included G. azzurrae, G. corvus and G. pseudoasper. Gephyromantis atsingy sp. n. has a snout-vent length of 35–43 mm and is a scansorial frog living among the Tsingy de Bemaraha pinnacles and inside the caves present in the area. A morphological analysis and biomolecular comparison revealed the degree of differentiation between these four species of the Phylacomantis subgenus. The new species seems to be endemic to Tsingy de Bemaraha.

  1. Blood parasites of frogs from an equatorial African montane forest in western Uganda.

    Science.gov (United States)

    Readel, Anne M; Goldberg, Tony L

    2010-04-01

    In a survey of blood parasites in Ugandan frogs, 30 (17%) of 180 frogs were infected with at least 1 species of Hepatozoon or Trypanosoma, or with microfilariae. There were significant differences in the prevalence of parasitism among species, with parasitemia detected in only 3 of 9 species. The intensity of blood parasite infection ranged from 1 to 1,080 infected cells per 5,000 cells examined. Seasonal changes in the prevalence and intensity of parasitemia were not observed, nor was there any association between parasitemia and infection with the pandemic fungus Batrachochytrium dendrobatidis.

  2. Cost-effective conservation of an endangered frog under uncertainty.

    Science.gov (United States)

    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

  3. Ciguatoxin enhances quantal transmitter release from frog motor nerve terminals.

    Science.gov (United States)

    Molgó, J.; Comella, J. X.; Legrand, A. M.

    1990-01-01

    1. Ciguatoxin (CTX), a marine toxin produced by the benthic dinoflagellate Gambierdiscus toxicus, is responsible for a complex endemic disease in man known as ciguatera fish poisoning. In the present study we have investigated the effects of purified CTX extracted for Gymnothorax javanicus moray-eel liver on frog isolated neuromuscular preparations with conventional electrophysiological techniques. 2. CTX (1-2.5 nM) applied to cutaneous pectoris nerve-muscle preparations induced, after a short delay, spontaneous fibrillations of the muscle fibres that could be suppressed with 1 microM tetrodotoxin (TTX) or by formamide to uncouple excitation-contraction. 3. In preparations treated with formamide, CTX (1-2.5 nM) caused either spontaneous or repetitive muscle action potentials (up to frequencies of 60-100 Hz) in response to a single nerve stimulus. Recordings performed at extrajunctional regions of the muscle membrane revealed that during the repetitive firing a prolongation of the repolarizing phase of the action potential occurred. At junctional sites the repetitive action potentials were triggered by repetitive endplate potentials (e.p.ps). 4. CTX (2.5 nM) caused a TTX-sensitive depolarization of the muscle membrane. 5. In junctions equilibrated in solutions containing high Mg2+ + low Ca2+, addition of CTX (1.5 nM) first induced an average increase of 239 +/- 36% in the mean quantal content of e.p.ps. Subsequently CTX reduced and finally blocked nerve-evoked transmitter release irreversibly. 6. CTX (1.5-2.5 nM) increased the frequency of miniature endplate potentials (m.e.p.ps) in junctions bathed either in normal Ringer, low Ca2(+)-high Mg2+ medium or in a nominally Ca2(+)-free solution containing EGTA.2+ Extensive washing with toxin-free solutions did not reverse the effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1972891

  4. Antitumor and angiostatic peptides from frog skin secretions.

    Science.gov (United States)

    van Zoggel, Hanneke; Hamma-Kourbali, Yamina; Galanth, Cécile; Ladram, Ali; Nicolas, Pierre; Courty, José; Amiche, Mohamed; Delbé, Jean

    2012-01-01

    The discovery of new molecules with potential antitumor activity continues to be of great importance in cancer research. In this respect, natural antimicrobial peptides isolated from various animal species including humans and amphibians have been found to be of particular interest. Here, we report the presence of two anti-proliferative peptides active against cancer cells in the skin secretions of the South American tree frog, Phyllomedusa bicolor. The crude skin exudate was fractioned by size exclusion gel followed by reverse-phase HPLC chromatography. After these two purification steps, we identified two fractions that exhibited anti-proliferative activity. Sequence analysis indicated that this activity was due to two antimicrobial α-helical cationic peptides of the dermaseptin family (dermaseptins B2 and B3). This result was confirmed using synthetic dermaseptins. When tested in vitro, synthetic B2 and B3 dermaseptins inhibited the proliferation of the human prostatic adenocarcinoma PC-3 cell line by more than 90%, with an EC(50) of around 2-3 μM. No effect was observed on the growth of the NIH-3T3 non-tumor mouse cell line with Drs B2, whereas a slight inhibiting effect was observed with Drs B3 at high dose. In addition, the two fractions obtained after size exclusion chromatography also inhibited PC-3 cell colony formation in soft agar. Interestingly, inhibition of the proliferation and differentiation of activated adult bovine aortic endothelial cells was observed in cells treated with these two fractions. Dermaseptins B2 and B3 could, therefore, represent interesting new pharmacological molecules with antitumor and angiostatic properties for the development of a new class of anticancer drugs.

  5. Passive ionic properties of frog retinal pigment epithelium.

    Science.gov (United States)

    Miller, S S; Steinberg, R H

    1977-09-15

    The isolated pigment epithelium and choroid of frog was mounted in a chamber so that the apical surfaces of the epithelial cells and the choroid were exposed to separate solutions. The apical membrane of these cells was penetrated with microelectrodes and the mean apical membrane potential was --88 mV. The basal membrane potential was depolarized by the amount of the transepithelial potential (8--20 mV). Changes in apical and basal cell membrane voltage were produced by changing ion concentrations on one or both sides of the tissue. Although these voltage changes were altered by shunting and changes in membrane resistance, it was possible to estimate apical and basal cell membrane and shunt resistance, and the relative ionic conductance Ti of each membrane. For the apical membrane: TK approximately equal to 0.52, THCO3 approximately equal to 0.39 and TNa approximately equal to 0.05, and its specific resistance was estimated to be 6000--7000 omega cm2. For the basal membrane: TK approximately equal to 0.90 and its specific resistance was estimated to be 400--1200 omega cm2. From the basal potassium voltage responses the intracellular potassium concentration was estimated at 110 mM. The shunt resistance consisted of two pathways: a paracellular one, due to the junctional complexes and another, around the edge of the tissue, due to the imperfect nature of the mechanical seal. In well-sealed tissues, the specific resistance of the shunt was about ten times the apical plus basal membrane specific resistances. This epithelium, therefore, should be considered "tight". The shunt pathway did not distinguish between anions (HCO--3, Cl--, methylsulfate, isethionate) but did distinguish between Na+ and K+.

  6. Differentiation of frog fats from vegetable and marine oils by Fourier Transform Infrared Spectroscopy and chemometric analysis

    Directory of Open Access Journals (Sweden)

    A. N. Nina Naquiah

    2015-01-01

    Full Text Available The agro-based production and consumption of frogs coupled with world-wide trading have been increased in the recent years giving rise to the risk of frog fat adulteration in expensive vegetable and marine oils. For the first time, we profiled here frog fats using Fourier Transform Infrared (FTIR Spectroscopy coupled with multivariate principal component analysis (PCA. The comparison of the FTIR spectral absorbance intensities demonstrated linkage of frog fats to other edible fats and oils. Three commercially available marine oils and three vegetables oils were studied with frog fats and clear pattern of clusters with distinctive identifiable features were obtained through PCA modeling. PCA analysis identified 2922.21 cm-1, 2852.88 cm-1, 1745.45 cm-1, 1158.29 cm-1 and 721.51 cm-1 FTIR-frequencies as the most discriminating variables influencing the group separation into different clusters. This fundamental study has clear implications in the identification of frog fat from its marine and vegetable counterparts for the potential detection of frog fat adulteration in various fat and oils.

  7. Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Marga Born

    2010-07-01

    Full Text Available Seasonal rainfall affects tropical forest dynamics and behaviorof species that are part of these ecosystems. The positive correlation between amphibian activity patterns and rainfall has been demonstrated repeatedly. Members of Dendrobatidae, a clade of Neotropical dart-poison frogs, are well known for their habitat use and behavior during the rainy season, but their behavior during the dry season has received little attention. We studied habitat use and diet of the dendrobatid frog Dendrobates tinctorius in French Guiana during the rainy and dry seasons. Unlike many other dendrobatid frogs, D. tinctorius does not maintain territories for the entire rainy season. Both sexes colonize recently formed canopy-gaps and stay in these forest patches for only a few weeks. The frogs inthese patches consume a great diversity of prey, consisting of ants, beetles, wasps, insect larvae, and mites. During the dry season, frogs move to retreat sites in mature forest, such as palm bracts and tree holes. The frogs are less active and consume fewer prey items in the dry season, and they consume fewer wasps and insect larvae, but more termites. Ants are the most common prey items during both the wet and dry seasons. We discuss the effects of shifts in seasonal habitat use on the territorial behavior of dendrobatid frogs.

  8. Medicinal use of secretions (“the frog vaccine” from the kambô frog (Phyllomedusa bicolor by non-indigenous peoples in Rondônia, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Bernarde

    2009-09-01

    Full Text Available Amphibians have pharmaceutically active skin secretions that protect against infections and predation. Some indigenous people in southwestern Amazonia use these secretions from P. bicolor for medicinal purposes. While the use of these secretions by indigenous people is relatively well-known, the use by non-indigenous peoples is very poorly studied. Here we describe the use of the “frog vaccine” by non-indigenous populations in the Brazilian state of Rondônia. Thirty-one people who had received this “vaccine” were interviewed. The use of this vaccine is not typical or habitual in this region, and the person who administers the vaccine must travel from another part of Amazonia. Users of the vaccine come from middle and upper social classes with reasonable levels of education (primary, secondary and university. Approximately half the people vaccinated felt that their health had improved after vaccination and if need be, they would take the vaccination again. Most of the people do not know the frog species from which the secretions are taken. While the people who use this treatment believe that it is good for any infirmity, the medicinal properties, if any, of the “frog vaccine” are under study and are still unknown.

  9. Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

    Science.gov (United States)

    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.

  10. Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

    Science.gov (United States)

    Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

    2017-09-01

    Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

  11. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  12. Modeling Sexual Selection in Túngara Frog and Rationality of Mate Choice.

    Science.gov (United States)

    Vargas Bernal, Esteban; Sanabria Malagon, Camilo

    2017-12-01

    The males of the species of frogs Engystomops pustulosus produce simple and complex calls to lure females, as a way of intersexual selection. Complex calls lead males to a greater reproductive success than what simple calls do. However, the complex calls are also more attractive to their main predator, the bat Trachops cirrhosus. Therefore, as M. Ryan suggests in (The túngara frog: a study in sexual selection and communication. University of Chicago Press, Chicago, 1985), the complexity of the calls lets the frogs keep a trade-off between reproductive success and predation. In this paper, we verify this trade-off from the perspective of game theory. We first model the proportion of simple calls as a symmetric game of two strategies. We also model the effect of adding a third strategy, males that keep quiet and intercept females, which would play a role of intrasexual selection. Under the assumption that the decision of the males takes into account this trade-off between reproductive success and predation, our model reproduces the observed behavior reported in the literature with minimal assumption on the parameters. From the model with three strategies, we verify that the quiet strategy could only coexists with the simple and complex strategies if the rate at which quiet males intercept females is high, which explains the rarity of the quiet strategy. We conclude that the reproductive strategy of the male frog E. pustulosus is rational.

  13. COMPARATIVE ACTIVITY OF CECROPIN A AND POLYMYXIN B AGAINST FROG BACTERIAL PATHOGENS

    Directory of Open Access Journals (Sweden)

    Ermin Schadich

    2013-03-01

    Full Text Available The antimicrobial activity of two antimicrobial peptides, cecropin A and polymyxin B against different bacterial pathogens associated with bacterial dermatosepticemia, a fatal bacterial infectious disease of frogs was investigated. The peptides were tested in serial of concentrations (100-0.19 µg/ml for growth inhibition of seven pathogens: Aeromonas hydrophila, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Serratia liquefaciens. Their antimicrobial activity was compared with that of two antimicrobial peptides from frog skin, magainin 2 and aurein 2.1. Both cecropin A and polymyxin B, completely inhibited the growth of three pathogens: C. freundii, K. pneumoniae and P. aeruginosa at a concentration some sixteen times less than two skin peptides. Furthermore, cecropin A inhibited the growth of three pathogens resistant to the two skin peptides, A. hydrophila, C. meningosepticum and P. mirabilis. Polymyxin B also inhibited the growth of three pathogens resistant to the skin peptides, A. hydrophila, C. meningosepticum and S. liquefaciens. Cecropin A and polymyxin B have marked antibacterial activity against different frog bacterial pathogens indicating potential for therapeutic measures.Keywords: frogs, antimicrobial, bacteria, cecropin, polymyxin, resistance

  14. Chytrid Fungus, Batrachochytrium dendrobatidis , in Wild Populations of the Lake Titicaca Frog, Telmatobius culeus, in Peru.

    Science.gov (United States)

    Berenguel, Raul A; Elias, Roberto K; Weaver, Thomas J; Reading, Richard P

    2016-10-01

    The Lake Titicaca frog (Telmatobius culeus) is critically endangered, primarily from overexploitation. However, additional threats, such as chytrid fungus ( Batrachochytrium dendrobatidis ), are poorly studied. We found moderate levels of chytrid infection using quantitative PCR. Our results enhance our understanding of chytrid tolerance to high pH and low water temperature.

  15. A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae)

    NARCIS (Netherlands)

    Brown, J.L.; Twomey, E.; Amézquita, A.; Souza, M.B.; Caldwell, J.P.; Lötters, S.; May, R.; Melo-Sampaio, P.R.; Mejía-Vargas, D.; Perez-Peña, P.; Pepper, M.; Poelman, E.H.; Sanchez-Rodriguez, M.; Summers, K.

    2011-01-01

    The Neotropical poison frog genus Ranitomeya is revised, resulting in one new genus, one new species, five synonymies and one species classified as nomen dubium. We present an expanded molecular phylogeny that contains 235 terminals, 104 of which are new to this study. Notable additions to this

  16. Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Summers, Kyle

    2014-01-01

    study the Peruvian poison frog Ranitomeya imitator, a species that has undergone a mimetic radiation into four distinct morphs. Using a combination of colour–pattern analysis, landscape genetics and mate-choice experiments, we show that a mimetic shift in R. imitator is associated with a narrow...

  17. On Semiotics and Jumping Frogs: The Role of Gesture in the Teaching of Subtraction

    Science.gov (United States)

    Farrugia, Marie Therese

    2017-01-01

    In this article, I describe a research/teaching experience I undertook with a class of 5-year-old children in Malta. The topic was subtraction on the number line. I interpret the teaching/learning process through a semiotic perspective. In particular, I highlight the role played by the gesture of forming "frog jumps" on the number line.…

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

    Science.gov (United States)

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

    2009-08-07

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

  19. Long-Term United Kindrom Trends in the Breeding Phenology of the Common Frog, Rana temporaria

    Czech Academy of Sciences Publication Activity Database

    Scott, W.A.; Pithart, David; Adamson, J. K.

    2008-01-01

    Roč. 42, č. 1 (2008), s. 89-96 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z60870520 Keywords : Long-term * Common Frog * Breeding * Rana temporaria Subject RIV: EG - Zoology Impact factor: 0.888, year: 2008

  20. 78 FR 53581 - Endangered and Threatened Wildlife and Plants; Threatened Status for Oregon Spotted Frog

    Science.gov (United States)

    2013-08-29

    ...). Oregon spotted frogs breed in shallow pools (2-12 in (5-30 cm) deep) that are near flowing water, or... to: Public Comments Processing, Attn: FWS-R1-ES-2013-0013; Division of Policy and Directives... Friesz 1998, p. 3). They are laid in shallow, often temporary, pools of water; gradually receding...

  1. Mimetic Divergence and the Speciation Continuum in the Mimic Poison Frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Venegas, Pablo J.

    2016-01-01

    While divergent ecological adaptation can drive speciation, understanding the factors that facilitate or constrain this process remains a major goal in speciation research. Here, we study two mimetic transition zones in the poison frog Ranitomeya imitator, a species that has undergone a Mullerian...

  2. Does the Peer Group Matter? Assessing Frog Pond Effects in Transition to Secondary Schooling

    DEFF Research Database (Denmark)

    Skov, Peter Rohde

    In this paper, I investigate whether a social comparison mechanism affects the choice of secondary schooling. I investigate the theory of frog pond effects on choice of upper secondary education using school-by-grade fixed effects models and comprehensive administrative data. I examine the non...

  3. The impact of fish and drought on frog breeding in temporary waters ...

    African Journals Online (AJOL)

    The breeding of frogs in four ponds near Harare, Zimbabwe, was investigated during a wet rainy season (2000/01) and a dry one (2001/02). During 2000/01 eight and nine species bred in two ponds in abandoned gravel pits that never contained fish, but only four species bred in these in 2001/02 and the relative abundance ...

  4. Inherent rhythmcity and interstitial cells of Cajal in a frog vein

    Indian Academy of Sciences (India)

    Interstitial cells of Cajal are responsible for rhythmic contractions of the musculature of the gastrointestinal tract and blood vessels. The existence of these cells and spontaneous rhythmicity were noticed in amphibian vein and the findings are reported in this paper. The postcaval vein was identified in the frog, Rana tigrina ...

  5. Formation of cell masses in the myelencephalon of the clawed frog ...

    African Journals Online (AJOL)

    An important process in the organization of developing nervous system is the clustering of neurons with similar properties to form nuclei. The development of myelencephalon of Xenopus muelleri, a pipid frog that retains a lateral line system throughout life, was studied in Nissl stained serial sections. The results showed that ...

  6. Schellackia (Apicomplexa: Eimeriidae of the brazilian tree-frog, Phrynohyas venulosa (Amphibia: Anura from Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    I. Paperna

    1995-10-01

    Full Text Available Endogenous stages of a Schellackia species are described in histological sections of the intestine of the tree-frog, Phrynohyas venulosa, from North Brazil. Most oocysts sporulate within the epithelial cells of the gut, but a few were detected in the lamina propria.

  7. Cryptic species of sharp-nosed reed frogs in the Hyperolius nasutus ...

    African Journals Online (AJOL)

    The sharp-nosed reed frog is widespread in Africa. Although currently recognized as one species, suggestions have been made that more than one species might exist. We analysed 237 calls of 69 males from 19 localities in the western to southern parts of Africa. Calls fall into three groups, which we recognize as cryptic ...

  8. ICE on the road to auditory sensitivity reduction and sound localization in the frog.

    Science.gov (United States)

    Narins, Peter M

    2016-10-01

    Frogs and toads are capable of producing calls at potentially damaging levels that exceed 110 dB SPL at 50 cm. Most frog species have internally coupled ears (ICE) in which the tympanic membranes (TyMs) communicate directly via the large, permanently open Eustachian tubes, resulting in an inherently directional asymmetrical pressure-difference receiver. One active mechanism for auditory sensitivity reduction involves the pressure increase during vocalization that distends the TyM, reducing its low-frequency airborne sound sensitivity. Moreover, if sounds generated by the vocal folds arrive at both surfaces of the TyM with nearly equal amplitudes and phases, the net motion of the eardrum would be greatly attenuated. Both of these processes appear to reduce the motion of the frog's TyM during vocalizations. The implications of ICE in amphibians with respect to sound localizations are discussed, and the particularly interesting case of frogs that use ultrasound for communication yet exhibit exquisitely small localization jump errors is brought to light.

  9. Description of a new moss frog from the south-western Cape (Anura ...

    African Journals Online (AJOL)

    A new species of moss frog, genus Arthroleptella, is described from the Kleinrivier mountains of the south-western Cape. It is morphologically indistinguishable from the other three species in the area. The four Cape species are allopatric, each has a unique male advertisement call, and preliminary molecular data shows ...

  10. Historical biogeography of Western Palaearctic pelobatid and pelodytid frogs: a molecular phylogenetic perspective

    NARCIS (Netherlands)

    Veith, M.; Fromhage, L.; Kosuch, J.; Vences, M.

    2006-01-01

    Spadefoot toads (Pelobates) and Parsley frogs (Pelodytes) are an enigmatic group of Western Palaearctic anurans. In the genus Pelobates, a fossorial lifestyle has enforced a conserved bauplan that masks their intraspecific evolutionary history. We used partial sequences of the mitochondrial 16S and

  11. Historical biogeography of Western Palearctic pelobatid and pelodytid frogs: a molecular phylogenetic perspective

    NARCIS (Netherlands)

    Veith, M.K.H.; Fromhage, L.; Kosuch, J.; Vences, M.

    2006-01-01

    Abstract Spadefoot toads (Pelobates) and Parsley frogs (Pelodytes) are an enigmatic group of Western Palaearctic anurans. In the genus Pelobates, a fossorial lifestyle has enforced a conserved bauplan that masks their intraspecific evolutionary history. We used partial sequences of the mitochondrial

  12. REGIONAL DYNAMICS OF WETLAND-BREEDING FROGS AND TOADS: TURNOVER AND SYNCHRONY

    Science.gov (United States)

    We used data from a statewide frog monitoring network to investigate population turnover and synchrony in eight wetland-breeding species. We found that subpopulations at many sites turn over frequently, with breeding choruses absent or undetectable in most years. Frequencies of d...

  13. Complete Genome Sequence of the Frog Pathogen Mycobacterium ulcerans Ecovar Liflandii

    NARCIS (Netherlands)

    Tobias, Nicholas J.; Doig, Kenneth D.; Medema, Marnix H.; Chen, Honglei; Haring, Volker; Moore, Robert; Seemann, Torsten; Stinear, Timothy P.

    In 2004, a previously undiscovered mycobacterium resembling Mycobacterium ulcerans (the agent of Buruli ulcer) was reported in an outbreak of a lethal mycobacteriosis in a laboratory colony of the African clawed frog Xenopus tropicalis. This mycobacterium makes mycolactone and is one of several

  14. Mating strategy and breeding patterns of the foothill yellow-legged frog (Rana boylii)

    Science.gov (United States)

    Clara A. Wheeler; Hartwell H. Welsh Jr.

    2008-01-01

    The Foothill Yellow-legged Frog (Rana boylii) has declined across much of its native range in California. Improper stream management may lower egg mass survival and reduce the availability of suitable breeding habitats. We collected data during six breeding-seasons (2002-2007) along an unregulated stream in northwestern California. We monitored...

  15. Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG.

    Science.gov (United States)

    Chen, Lingyun; Hefle, Sue L; Taylor, Steve L; Swoboda, Ines; Goodman, Richard E

    2006-07-26

    Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species. The 2D electrophoresis and immunoblots revealed species-specific differences in proteins that appear to represent various numbers of isoforms of parvalbumin in carp (5), catfish (3), cod (1) and tilapia (2). No parvalbumin was detected in yellowfin tuna. Based on minor differences in relative intensities of protein staining and immunodetection, parvalbumin isoforms may have slight differences in the epitope region recognized by the anti-frog parvalbumin antibody. These results suggest that the frog anti-parvalbumin antibody can be used as a valuable tool to detect parvalbumins from the fish tested in this study, except yellowfin tuna.

  16. Prevalence of Spirometra mansoni in dogs, cats, and frogs and its medical relevance in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    Qing Hong

    2016-12-01

    Conclusions: A high sparganum infection rate was observed in the wild frogs sold in agricultural product markets in Guangzhou. The infection was also serious in cats and dogs in Guangdong Province. With lifestyles and eating habits resulting in sparganum infection, it is necessary to focus on market management and community education in order to prevent the transmission of this disease in Guangzhou.

  17. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

    Directory of Open Access Journals (Sweden)

    E.V. Seliverstova

    2015-04-01

    Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

  18. Sensitive high frequency hearing in earless and partially eared harlequin frogs ()

    DEFF Research Database (Denmark)

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

    2018-01-01

    Harlequin frogs, genus Atelopus, communicate at high frequencies despite most species lacking a complete tympanic middle ear that facilitates high frequency hearing in most anurans and other tetrapods. Here we test whether Atelopus are better at sensing high frequency acoustic sound compared to o...

  19. Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

    Science.gov (United States)

    Zydlewski, Joseph D.; 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.

  20. Space use of Amazonian poison frogs: Testing the reproductive resource defense hypothesis

    NARCIS (Netherlands)

    Poelman, E.H.; Dicke, M.

    2008-01-01

    In most Anuran species, space use includes a lek mating system with defense of a calling site for only a short time period during an individual's lifespan. In contrast, territoriality over a longer time period by one or both of the sexes has been reported in all studied dendrobatid frogs. In most

  1. Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

    Science.gov (United States)

    Smalling, Kelly L.; Fellers, Gary M.; Kleeman, Patrick M.; Kuivila, Kathryn

    2013-01-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

  2. BIOMETRIC STUDY TO RANA RIDIBUNDA FROG SPECIES NEARNESS TO TIMISOARA LOCALITY

    Directory of Open Access Journals (Sweden)

    M. BURA

    2007-10-01

    Full Text Available Speciality literature provides little informations regarding Rana ridibunda frogbiometry. For supply this gap we studied the size and weight of 54 frogs sampled fromnearby Timişoara area ponds.The mean body lenght was 8,08 ± 0,54 cm for the females and respectively 6,17 ± 0,45cm for the males. Before evisceration on a par females weighted 62,28 ± 12,87 g andthe males 22,46 ± 5,3 g whereas after this action the carcase weighted 43,89 ± 8,91 gin the case of females and respectively 18,45 ± 4,42 g in the case of male lake frog. Themean leg lenght measured 12,59 ± 0,68 cm for female frogs and 9,78 ± 0,66 cm in thecase of male frogs. The hind stylopodium was estimated on a par as 13,23 ± 2,57 g forfemales and 5,33 ± 1,26 g for the males.

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

    Directory of Open Access Journals (Sweden)

    Richard W R Retallick

    2004-11-01

    Full Text Available 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.

  4. Tolerance of Frogs among High School Students: Influences of Disgust and Culture

    Science.gov (United States)

    Prokop, Pavol; Medina-Jerez, William; Coleman, Joy; Fancovicová, Jana; Özel, Murat; Fedor, Peter

    2016-01-01

    Amphibians play an important role in the functioning of ecosystems and some of them inhabit human gardens where they can successfully reproduce. The decline of amphibian diversity worldwide suggests that people may play a crucial role in their survival. We conducted a cross-cultural study on high school students' tolerance of frogs in Chile,…

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

    Science.gov (United States)

    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.

  6. Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

    Science.gov (United States)

    Kathleen Matthews; Haiganoush Preisler

    2010-01-01

    From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

  7. Biophysics of underwater hearing in the clawed frog, Xenopus laevis

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Elepfandt, A

    1995-01-01

    Anesthetized clawed frogs (Xenopus laevis) were stimulated with underwater sound and the tympanic disk vibrations were studied using laser vibrometry. The tympanic disk velocities ranged from 0.01 to 0.5 mm/s (at a sound pressure of 2 Pa) in the frequency range of 0.4-4 kHz and were 20-40 dB high...

  8. Effects of CFT Legumine (5% Rotenone) on tadpole survival and metamorphosis of Chiricahua leopard frogs Lithobates chiricahuensis, Northern leopard frogs L. pipiens, and American bullfrogs L. catesbeianus

    Science.gov (United States)

    Alvarez, Guillermo; Caldwell, Colleen A.; Kruse, Carter G.

    2017-01-01

    Amphibians may experience collateral effects if exposed to CFT Legumine (5% rotenone), a piscicide that is used to remove invasive fish. A series of 48-h static toxicity tests assessed the acute effects of CFT Legumine on multi-aged tadpoles of the federally listed Chiricahua leopard frog Lithobates chiricahuensis, the widespread northern leopard frog L. pipiens, and the increasingly invasive American bullfrog L. catesbeianus. At the earliest Gosner stages (GS 21–25), Chiricahua leopard frogs were more sensitive to CFT Legumine (median lethal concentration [LC50] = 0.41–0.58 mg/L) than American bullfrogs (LC50 = 0.63–0.69 mg/L) and northern leopard frogs (LC50 = 0.91 and 1.17 mg/L). As tadpoles developed (i.e., increase in GS), their sensitivity to rotenone decreased. In a separate series of 48-h static nonrenewal toxicity tests, tadpoles (GS 21–25 and GS 31–36) of all three species were exposed to piscicidal concentrations of CFT Legumine (0.5, 1.0, and 2.0 mg/L) to assess postexposure effects on metamorphosis. In survivors of all three species at both life stages, the time to tail resorption was nearly doubled in comparison with that of controls. For example, mid-age (GS 31–36) Chiricahua leopard frog tadpoles required 210.7 h to complete tail resorption, whereas controls required 108.5 h. However, because tail resorption is a relatively short period in metamorphosis, the total duration of development (days from posthatch to complete metamorphosis) and the final weight did not differ in either age-group surviving nominal concentrations of 0.5-, 1.0-, and 2.0-mg/L CFT Legumine relative to controls. This research demonstrates that the CFT Legumine concentrations commonly used in field applications to remove unwanted fish could result in considerable mortality of the earliest stages of Lithobates species. In addition to acute lethality, piscicide treatments may result in delayed tail resorption, which places the tadpoles at risk by increasing

  9. Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

    Directory of Open Access Journals (Sweden)

    Markus Menke

    2016-12-01

    Full Text Available The contents of the gular glands of the male African reed frog Hyperolius cinnamomeoventris consist of a mixture of aliphatic macrolides and sesquiterpenes. While the known macrolide gephyromantolide A was readily identified, the structure of another major component was suggested to be a tetradecen-13-olide. The synthesis of the two candidate compounds (Z-5- and (Z-9-tetradecen-13-olide revealed the former to be the naturally occurring compound. The synthesis used ring-closing metathesis as key step. While the Hoveyda–Grubbs catalyst furnished a broad range of isomeric products, the (Z-selective Grubbs catalyst lead to pure (Z-products. Analysis by chiral GC revealed the natural frog compound to be (5Z,13S-5-tetradecen-13-olide (1. This compound is also present in the secretion of other hyperoliid frogs as well as in femoral glands of male mantellid frogs such as Spinomantis aglavei. The mass spectra of the synthesized macrolides as well as their rearranged isomers obtained during ring-closing metathesis showed that it is possible to assign the location of the double bond in an unsaturated macrolide on the basis of its EI mass spectrum. The occurrence of characteristic ions can be explained by the fragmentation pathway proposed in the article. In contrast, the localization of a double bond in many aliphatic open-chain compounds like alkenes, alcohols or acetates, important structural classes of pheromones, is usually not possible from an EI mass spectrum. In the article, we present the synthesis and for the first time elucidate the structure of macrolides from the frog family Hyperoliidae.

  10. A comparative study of charge movement in rat and frog skeletal muscle fibres.

    Science.gov (United States)

    Hollingworth, S; Marshall, M W

    1981-12-01

    1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

  11. Hibernal habitat selection by Wood Frogs (Lithobates sylvaticus) in a northern New England montane landscape

    Science.gov (United States)

    Groff, Luke A.; Calhoun, Aram J.K.; Loftin, Cynthia S.

    2016-01-01

    Poikilothermic species, such as amphibians, endure harsh winter conditions via freeze-tolerance or freeze-avoidance strategies. Freeze-tolerance requires a suite of complex, physiological mechanisms (e.g., cryoprotectant synthesis); however, behavioral strategies (e.g., hibernal habitat selection) may be used to regulate hibernaculum temperatures and promote overwintering survival. We investigated the hibernal ecology of the freeze-tolerant Wood Frog (Lithobates sylvaticus) in north-central Maine. Our objectives were to characterize the species hibernaculum microclimate (temperature, relative humidity), evaluate hibernal habitat selection, and describe the spatial arrangement of breeding, post-breeding, and hibernal habitats. We monitored 15 frogs during two winters (2011/12: N = 10; 2012/13: N = 5), measured hibernal habitat features at micro (2 m) and macro (10 m) spatial scales, and recorded microclimate hourly in three strata (hibernaculum, leaf litter, ambient air). We compared these data to that of 57 random locations with logistic regression models, Akaike Information Criterion, and Kolmogorov–Smirnov tests. Hibernaculum microclimate was significantly different and less variable than leaf litter, ambient air, and random location microclimate. Model averaging indicated that canopy cover (−), leaf litter depth (+), and number of logs and stumps (+; microhabitat only) were important predictors of Wood Frog hibernal habitat. These habitat features likely act to insulate hibernating frogs from extreme and variable air temperatures. For example, decreased canopy cover facilitates increased snowpack depth and earlier snowpack accumulation and melt. Altered winter temperature and precipitation patterns attributable to climate change may reduce snowpack insulation, facilitate greater temperature variation in the underlying hibernacula, and potentially compromise Wood Frog winter survival.

  12. Road Impacts on Abundance, Call Traits, and Body Size of Rainforest Frogs in Northeast Australia

    Directory of Open Access Journals (Sweden)

    Conrad J. Hoskin

    2010-09-01

    Full Text Available Frogs are potentially sensitive indicators of road impacts, with studies indicating particular susceptibility to road mortality. Calling, i.e., breeding, behavior could also be affected by traffic noise. We investigated effects on frog abundance and calling behavior where a busy highway crosses rainforest stream breeding habitat in northeast Australia. Frog abundance was repeatedly surveyed along five stream transects during a summer breeding season. Abundance of two species, Litoria rheocola and Austrochaperina pluvialis, increased significantly with perpendicular distance from the road along two transects. No trends in abundance were detected for A. pluvialis on two other transects where it was common, or for Litoria serrata on one transect where abundance was sufficient for analysis. Both species with lowered abundance near the road, L. rheocola and A. pluvialis, are rare in road kill statistics along this highway, suggesting road mortality is not the cause of reduced frog abundance near the road. We postulate that lowered abundance may reflect traffic noise effects. We analyzed calls of the International Union for Conservation of Nature endangered species L. rheocola along the one stream transect on which it was common. We found significant trends in two call traits over a very fine scale: both call rate and dominant frequency were significantly higher closer to the road. Furthermore, males were significantly smaller closer to the road. These call and body size trends most likely reflect road impacts, but resolving these is complicated by correlations between traits. Potential mechanisms, effects on fitness, and management recommendations to mitigate the impacts of roads on frogs are outlined.

  13. Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2016-12-01

    Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

  14. Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin, USA.

    Science.gov (United States)

    Arkle, Robert S; Pilliod, David S

    2015-09-01

    A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale habitat availability and distribution, (2) water body-scale habitat associations, and (3) resource management-identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species' range. Within these suitable areas, native and non-native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper- and lower-elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non-native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator-free refugia, and a commensalistic interaction with an ecosystem

  15. More similar than you think: Frog metamorphosis as a model of human perinatal endocrinology.

    Science.gov (United States)

    Buchholz, Daniel R

    2015-12-15

    Hormonal control of development during the human perinatal period is critically important and complex with multiple hormones regulating fetal growth, brain development, and organ maturation in preparation for birth. Genetic and environmental perturbations of such hormonal control may cause irreversible morphological and physiological impairments and may also predispose individuals to diseases of adulthood, including diabetes and cardiovascular disease. Endocrine and molecular mechanisms that regulate perinatal development and that underlie the connections between early life events and adult diseases are not well elucidated. Such mechanisms are difficult to study in uterus-enclosed mammalian embryos because of confounding maternal effects. To elucidate mechanisms of developmental endocrinology in the perinatal period, Xenopus laevis the African clawed frog is a valuable vertebrate model. Frogs and humans have identical hormones which peak at birth and metamorphosis, have conserved hormone receptors and mechanisms of gene regulation, and have comparable roles for hormones in many target organs. Study of molecular and endocrine mechanisms of hormone-dependent development in frogs is advantageous because an extended free-living larval period followed by metamorphosis (1) is independent of maternal endocrine influence, (2) exhibits dramatic yet conserved developmental effects induced by thyroid and glucocorticoid hormones, and (3) begins at a developmental stage with naturally undetectable hormone levels, thereby facilitating endocrine manipulation and interpretation of results. This review highlights the utility of frog metamorphosis to elucidate molecular and endocrine actions, hormone interactions, and endocrine disruption, especially with respect to thyroid hormone. Knowledge from the frog model is expected to provide fundamental insights to aid medical understanding of endocrine disease, stress, and endocrine disruption affecting the perinatal period in humans

  16. Population genetics of the Chilean frog Batrachyla Leptopus (Leptodactylidae

    Directory of Open Access Journals (Sweden)

    J.R. Formas

    2000-03-01

    Full Text Available Electrophoretic variation of proteins encoded by 14 loci was analyzed in eight (five continental and three insular populations of the Chilean leptodactylid frog Batrachyla leptopus. The overall proportion of polymorphic loci was estimated to be 18.7% and the average number of alleles per locus, 1.2, while observed and expected heterozygosities were 1.7 and 5.1%, respectively. The estimated coefficient of genetic identity was 0.940; the corresponding figure for genetic distance was 0.063. F-statistics analysis showed a total inbreeding coefficient (Fit of 0.855 and high levels of genetic subdivision (Fst = 0.596 as well as of inbreeding within populations (Fis = 0.640. However, there was only a moderate level of genetic differentiation (Fst = 0.181 between the insular group of populations and the continental group.A variação eletroforética de proteínas codificadas por 14 loci foi analisada em oito populações (5 continentais e 3 insulares da rã leptodactilídea chilena Batrachyla leptopus. A proporção geral de loci polimórficos foi estimada como sendo de 18,7% e o número médio de alelos por loco, 1,2, enquanto que as heterozigosidades observada e esperada foram 1,7 e 5,1%, respectivamente. O coeficiente esperado de identidade genética foi 0,940; o número correspondente para a distância genética foi 0,063. A análise estatística F mostrou um coeficiente de endogamia total (Fit de 0,855 e altos níveis de subdivisão genética (Fst = 0,596, assim como de endogamia dentro das populações (Fis = 0,640. Contudo, houve apenas um nível moderado de diferenciação genética (Fst = 0,181 entre o grupo insular de populações e o grupo continental.

  17. Minimal health impacts but detectable tissue residues after exposure of northern leopard frogs (Lithobates pipiens) to commercial naphthenic acids

    International Nuclear Information System (INIS)

    Hersikorn, B.; Young, R.; Fedorak, P.; Smits, J.

    2010-01-01

    This presentation reported on a study that examined whether naphthenic acids (NAs) are a toxic component in oil sands process-affected materials (OSPM). The study investigated the toxicity of commercial (Refined Merichem) NAs to native amphibians (northern leopard frogs) exposed to saline conditions comparable to those of reclaimed wetlands on oil sand leases. Gas chromatography-mass spectroscopy analysis showed that the exposure of frogs to NAs solutions for 28 days resulted in proportional NA concentrations in extracts of frog muscle tissue. Biological assays were performed to determine if the increasing exposure to NAs caused a proportional compromise in the health of test animals. The innate immune function, thyroid hormones, and hepatic detoxification enzyme induction did not differ in response to increased tissue concentrations of NAs. The commercial NAs were absorbed and deposited in muscle tissue. It was concluded that NAs play only a small, if any, role in the toxicity of OSPM to frogs.

  18. Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

    2014-01-01

    The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

  19. Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous–Paleogene boundary

    Science.gov (United States)

    Feng, Yan-Jie; Liang, Dan; Hillis, David M.; Cannatella, David C.; Zhang, Peng

    2017-01-01

    Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous–Paleogene (K–Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K–Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation. PMID:28673970

  20. Peptidomic approach identifies cruzioseptins, a new family of potent antimicrobial peptides in the splendid leaf frog, Cruziohyla calcarifer

    OpenAIRE

    Proaño Bolaños, Carolina; Zhou, Mei; Wang, Lei; Luis, Coloma; Chen, Tianbao; Shaw, Christopher

    2016-01-01

    Phyllomedusine frogs are an extraordinary source of biologically active peptides. At least 8 families of antimicrobial peptides have been reported in this frog clade, the dermaseptins being the most diverse. By a peptidomic approach, integrating molecular cloning, Edman degradation sequencing and tandem mass spectrometry, a new family of antimicrobial peptides has been identified in Cruziohyla calcarifer. These 15 novel antimicrobial peptides of 20–32 residues in length are named cruzioseptin...

  1. Tool path planning of hole-making operations in ejector plate of injection mould using modified shuffled frog leaping algorithm

    Directory of Open Access Journals (Sweden)

    Amol M. Dalavi

    2016-07-01

    Full Text Available Optimization of hole-making operations in manufacturing industry plays a vital role. Tool travel and tool switch planning are the two major issues in hole-making operations. Many industrial applications such as moulds, dies, engine block, automotive parts etc. requires machining of large number of holes. Large number of machining operations like drilling, enlargement or tapping/reaming are required to achieve the final size of individual hole, which gives rise to number of possible sequences to complete hole-making operations on the part depending upon the location of hole and tool sequence to be followed. It is necessary to find the optimal sequence of operations which minimizes the total processing cost of hole-making operations. In this work, therefore an attempt is made to reduce the total processing cost of hole-making operations by applying relatively new optimization algorithms known as shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm for the determination of optimal sequence of hole-making operations. An industrial application example of ejector plate of injection mould is considered in this work to demonstrate the proposed approach. The obtained results by the shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm are compared with each other. It is seen from the obtained results that the results of proposed modified shuffled frog leaping algorithm are superior to those obtained using shuffled frog leaping algorithm.

  2. Bioaccumulation of polychlorinated biphenyls in ranid frogs and northern water snakes from a hazardous waste site and a contaminated watershed.

    Science.gov (United States)

    Fontenot, L W; Noble, G P; Akins, J M; Stephens, M D; Cobb, G P

    2000-04-01

    Livers of bullfrogs (Rana catesbeiana) from a polychlorinated biphenyl (PCB) contaminated watershed and hazardous waste site located in Pickens County, South Carolina, contained significantly higher concentrations of PCBs (2.33 and 2.26 ppm, respectively) than those from a reference site (0.05 ppm). Green frogs (R. clamitans) from the two contaminated sites also accumulated higher levels of PCBs (2.37 and 3.88 ppm, respectively) than those from the reference site (0.02 ppm). No temporal variation was observed in PCB concentrations of bullfrogs or green frogs from the contaminated sites between 1992 and 1993. Levels of PCBs in the livers of northern water snakes (Nerodia sipedon) were significantly higher in snakes from the contaminated watershed (13.70 ppm) than in those from the waste site (2.29 ppm) and two reference sites (2.50 and 1.23 ppm). When compared to frogs, significantly higher bioaccumulation occurred in water snakes from the contaminated watershed. No significant differences in PCB levels were found with respect to sex or body size (snout-vent length (SVL) or body mass) for frogs or snakes. PCBs were detected also in eggs of both frogs and snakes. Results of this study provide baseline data and document the bioaccumulation of PCB residues in frog and snake tissues; however, the significance of these tissue residues to reproduction, survival, growth/development, and population dynamics in contaminated habitats is unknown.

  3. Characterization of kappa 1 and kappa 2 opioid binding sites in frog (Rana esculenta) brain membrane preparation

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Varga, E.; Hepp, J.; Magyar, A.; Borsodi, A.; Wollemann, M.

    1990-09-01

    The distribution and properties of frog brain kappa-opioid receptor subtypes differ not only from those of the guinea pig brain, but also from that of the rat brain. In guinea pig cerebellum the kappa 1 is the dominant receptor subtype, frog brain contains mainly the kappa 2 subtype, and the distribution of the rat brain subtypes is intermediate between the two others. In competition experiments it has been established that ethylketocyclazocine and N-cyclopropylmethyl-norazidomorphine, which are nonselective kappa-ligands, have relatively high affinities to frog brain membranes. The kappa 2 ligands (Met5)enkephalin-Arg6-Phe7 and etorphine also show high affinities to the frog brain. Kappa 1 binding sites measured in the presence of 5 microM/D-Ala2-Leu5/enkephalin represent 25-30% of (3H)ethylketocyclazocine binding in frog brain membranes. The kappa 2 subtype in frog brain resembles more to the mu subtype than the delta subtype of opioid receptors, but it differs from the mu subtype in displaying low affinity toward beta-endorphin and /D-Ala2-(Me)Phe4-Gly5-ol/enkephalin (DAGO). From our data it is evident that the opioid receptor subtypes are already present in the amphibian brain but the differences among them are less pronounced than in mammalian brain.

  4. Characterization of kappa 1 and kappa 2 opioid binding sites in frog (Rana esculenta) brain membrane preparation

    International Nuclear Information System (INIS)

    Benyhe, S.; Varga, E.; Hepp, J.; Magyar, A.; Borsodi, A.; Wollemann, M.

    1990-01-01

    The distribution and properties of frog brain kappa-opioid receptor subtypes differ not only from those of the guinea pig brain, but also from that of the rat brain. In guinea pig cerebellum the kappa 1 is the dominant receptor subtype, frog brain contains mainly the kappa 2 subtype, and the distribution of the rat brain subtypes is intermediate between the two others. In competition experiments it has been established that ethylketocyclazocine and N-cyclopropylmethyl-norazidomorphine, which are nonselective kappa-ligands, have relatively high affinities to frog brain membranes. The kappa 2 ligands (Met5)enkephalin-Arg6-Phe7 and etorphine also show high affinities to the frog brain. Kappa 1 binding sites measured in the presence of 5 microM/D-Ala2-Leu5/enkephalin represent 25-30% of [3H]ethylketocyclazocine binding in frog brain membranes. The kappa 2 subtype in frog brain resembles more to the mu subtype than the delta subtype of opioid receptors, but it differs from the mu subtype in displaying low affinity toward beta-endorphin and /D-Ala2-(Me)Phe4-Gly5-ol/enkephalin (DAGO). From our data it is evident that the opioid receptor subtypes are already present in the amphibian brain but the differences among them are less pronounced than in mammalian brain

  5. Calling at the highway: The spatiotemporal constraint of road noise on Pacific chorus frog communication.

    Science.gov (United States)

    Nelson, Danielle V; Klinck, Holger; Carbaugh-Rutland, Alexander; Mathis, Codey L; Morzillo, Anita T; Garcia, Tiffany S

    2017-01-01

    Loss of acoustic habitat due to anthropogenic noise is a key environmental stressor for vocal amphibian species, a taxonomic group that is experiencing global population declines. The Pacific chorus frog ( Pseudacris regilla ) is the most common vocal species of the Pacific Northwest and can occupy human-dominated habitat types, including agricultural and urban wetlands. This species is exposed to anthropogenic noise, which can interfere with vocalizations during the breeding season. We hypothesized that Pacific chorus frogs would alter the spatial and temporal structure of their breeding vocalizations in response to road noise, a widespread anthropogenic stressor. We compared Pacific chorus frog call structure and ambient road noise levels along a gradient of road noise exposures in the Willamette Valley, Oregon, USA. We used both passive acoustic monitoring and directional recordings to determine source level (i.e., amplitude or volume), dominant frequency (i.e., pitch), call duration, and call rate of individual frogs and to quantify ambient road noise levels. Pacific chorus frogs were unable to change their vocalizations to compensate for road noise. A model of the active space and time ("spatiotemporal communication") over which a Pacific chorus frog vocalization could be heard revealed that in high-noise habitats, spatiotemporal communication was drastically reduced for an individual. This may have implications for the reproductive success of this species, which relies on specific call repertoires to portray relative fitness and attract mates. Using the acoustic call parameters defined by this study (frequency, source level, call rate, and call duration), we developed a simplified model of acoustic communication space-time for this species. This model can be used in combination with models that determine the insertion loss for various acoustic barriers to define the impact of anthropogenic noise on the radius of communication in threatened species

  6. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China); Jia Xiuying, E-mail: hznujiaxiuying@126.com [Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province, 310036 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. Black-Right-Pointing-Pointer Cd can result in oxidative stress in the frog testes. Black-Right-Pointing-Pointer Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. Black-Right-Pointing-Pointer Cd can cause apoptosis in the testes of male R. limnocharis. Black-Right-Pointing-Pointer Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd{sup 2+} solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a

  7. Anfíbios Anuros do Distrito Federal The Frogs of the Federal District of Brazil

    Directory of Open Access Journals (Sweden)

    Bertha Lutz

    1954-03-01

    Full Text Available The frogs of the Federal District of Brazil are listed and discussed as to habit, biology and ecology. The F. D is situated 22° 54' 24" S. & 43° 10' 21" W Gr. and comprises 1.356 km². Its topography includes sea-shore, maritime scrub, lagoons, plains and marsh, open slopes, forested mountains and great heads of rock. Three thousand feet of altitude are attained at two points. Fifty two different frogs occur in the F.D. Three fifths of them live in open country. Two fifths of these have never been found above the plains; the others range higher but mostly in open country. Their environment offers conditions suitable for average tadpoles and adults. these frogs are more or less unspecialized. There are six genera and thirty species. Two thirds of the latter belong to the type genera of the large neotropical families Bufonidae, Leptodactylidae and Hylidae. Only in the maritime scrub formation are conditions somewhat different. Water for average tadpoles is provided by the lagoons. The xerophytism of the vegetation is, however, so marked that bromeliads growing on the ground provide almost the only appropriate shelter for adult tree-frogs used to sleeping upright on the vegetation. One large Hylid genus lives entirely in them. It is casque-headed and phragmotic, shutting the lumen of the leaf-cup with head used as a plug. Another large Hylid genus shows a lesser degree of the same specialization. (Lutz A & Lutz B, 1939 II. One genus with two species is entirely saxicolous; it lives on wet ledges of rock at all phases of its life history. (B. Lutz 1948. The other two fifths of the frogs from F. D. are montane forest forms. Their environment offers numerous and varied biotopes and is near optimum for adults. There is,however, hardly any standing water available for larvae. These frogs are ecologically diversified. They also show a general trend towards spawning in the adult biotipe, which leads to delayed hatching, semi-aquatic and terrestrial

  8. Medicinal use of secretions (“the frog vaccine”) from the kambô frog (Phyllomedusa bicolor) by non-indigenous peoples in Rondônia, Brazil

    OpenAIRE

    Paulo Sérgio Bernarde; Rosimeyri Aparecida Santos

    2009-01-01

    Amphibians have pharmaceutically active skin secretions that protect against infections and predation. Some indigenous people in southwestern Amazonia use these secretions from P. bicolor for medicinal purposes. While the use of these secretions by indigenous people is relatively well-known, the use by non-indigenous peoples is very poorly studied. Here we describe the use of the “frog vaccine” by non-indigenous populations in the Brazilian state of Rondônia. Thirty-one people who had receive...

  9. Modelling the impact of roads on regional population of Moor frogs (Rana arvalis)

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt

    for decisions concerning road lay-out and mitigation measures. As model species was chosen the Moor frog (Rana arvalis). Populations of Moor frogs are assumed to follow a pattern of metapopulation dynamics, with colonisation, extinction and recolonisation of suitable habitat patches. Thus, road constructions...... to be constructed and analysed. The first scenario should be a map of the area as it is before the planned road construction (scenario 0). This analysis measures the ecological performance of the original landscape and is a reference against which other scenarios are to be compared. The second map (scenario 1......) should show the landscape as it is expected to be after the road constructions. In combination, the analyses of scenario 0 and scenario 1 make it possible to assess the effect of road construction on connectivity and population persistence. The analyses also constitute the basis for planning...

  10. Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium

    DEFF Research Database (Denmark)

    Madsen, K H; Brodin, Birger; Nielsen, R

    1999-01-01

    In the present study we investigated the possible existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium and whether such a mechanism plays a role in the regulation of transepithelial Na+ transport. Cytosolic calcium ([Ca2+]i) was measured with the probe...... in serosal Na+ were followed by stepwise changes in [Ca2+]i. These observations indicate the existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium. The transepithelial Na+ transport decreased from 13.2+/-1.8 to 9.2+/-1.5 microA cm-2 (n=8, P=0.049) when Na...

  11. Calcium regulation in frog peripheral nerve by the blood-nerve barrier

    International Nuclear Information System (INIS)

    Wadhwani, K.C.

    1986-01-01

    The objectives of this research were: (a) to investigate the characteristics of calcium transport across the perineurium and the endoneurial capillaries, and (b) to gain a better understanding of the extent of calcium homeostasis in the endoneurial space. To study the nature of calcium transport across the perineurium, the flux of radiotracer 45 Ca was measured through the perineurial cylinder, isolated from the frog sciatic nerve, and through the perineurium into the nerve in situ. To study the nature of calcium transport across the endoneurial capillaries, the permeability-surface area product (PA) of 45 Ca was determined as a function of the calcium concentration in the blood. To study calcium homeostasis, the calcium content of the frog sciatic nerve was determined as a function of chronic changes in plasma [Ca

  12. Perbedaan jenis bahan penyamak terhadap sifat fisik kulit katak bull frog

    Directory of Open Access Journals (Sweden)

    Mochtar Lutfie

    1997-06-01

    Full Text Available The Obyective of this research is to study the effects of various tanning agents on the qualities of leather made from Bull Frog skin. Fifteen pieces of wet salted Bull Frog from Malang were tanned with several tanning agents, wich are mineral (10% Chromosal B, vegetable (10% Mimosa extract and synthetic tensile strengths and elongations. Its turned out that vegetable tanning agent gave the higest tensile strength (279,62 kg/cm2, while mineral tanning agent gave the lowest one (183.04 kg/cm2. It showed that the type of tanning agent used significantly effects the tensile strength of the leather produced (p ≤ 0.005. On the other hand, mineral tanning agent gave the higest elongation (105.20%. While vegetable tanning agent gave the lowest one (91.20%. This result implied that the type of tanning agent used has a significant effect on the elongation (p ≤ 0.01.

  13. Bone marrow reconstitution of immune responses following irradiation in the leopard frog, Rana pipiens

    International Nuclear Information System (INIS)

    Ramirez, J.A.; Wright, R.K.; Cooper, E.L.

    1983-01-01

    The bone marrow of Rana is an important source of cells capable of maintaining individual viability, responding to Concanavalin A (Con A) and producing PFC against sheep erythrocyte (SRBC) antigens. Frog marrow is more effective than the spleen in maintaining life. Radiation destroys the ability of frogs to respond to SRBC immunization (lack of bone marrow and spleen PFC, serum antibody) and bone marrow/spleen cells to respond to Con A, i.e., bone marrow and spleen contain radiation-sensitive cells. Shielding one hind leg during irradiation leads to reconstitution of bone marrow/spleen PFC responses, antibody synthesis and individual viability. Our results suggest that bone marrow is: a) the source of stem cells, and b) the source of mature T- and B- lymphocytes that can recirculate within the immune system

  14. Wet adhesion with application to tree frog adhesive toe pads and tires

    International Nuclear Information System (INIS)

    Persson, B N J

    2007-01-01

    Strong adhesion between solids with rough surfaces is only possible if at least one of the solids is elastically very soft. Some lizards and spiders are able to adhere (dry adhesion) and move on very rough vertical surfaces due to very compliant surface layers on their attachment pads. Flies, bugs, grasshoppers and tree frogs have less compliant pad surface layers, and in these cases adhesion to rough surfaces is only possible because the animals inject a wetting liquid into the pad-substrate contact area, which generates a relative long-range attractive interaction due to the formation of capillary bridges. In this presentation I will discuss some aspects of wet adhesion for tree frogs and give some comments related to tire applications

  15. Dependence of Ca outflow and depression of frog myocardium contraction on ryodipine concentration.

    Science.gov (United States)

    Narusevicius, E; Gendviliene, V; Macianskiene, R; Hmelj-Dunai, G; Velena, A; Duburs, G

    1988-02-01

    The effect of ryodipine on calcium outflow from tissues, on contraction force, the duration of action potentials and the relaxation phase time-constant in the contraction cycles of myocardial strips was studied using frog heart preparations. It was found that calcium outflow (delta Ca) as a function on ryodipine concentration can be represented as: (formula; see text) A linear correlation exists between Ca2+, contraction blocking and the shortening of the action potential in the presence of various ryodipine concentrations. Ryodipine (10(-5) mol/l) decreased the relaxation time-constant by about 20% as compared to controls. It was concluded that calcium outflow from myocardial tissues in response to ryodipine is due to blockade of calcium entry into the cells and their output through the Na+--Ca2+ exchange system. Frog heart myocardial contractions are essentially under the control of calcium entry through sarcolemmal calcium channels.

  16. Wet adhesion with application to tree frog adhesive toe pads and tires

    Energy Technology Data Exchange (ETDEWEB)

    Persson, B N J [IFF, FZ-Juelich, 52425 Juelich (Germany)

    2007-09-19

    Strong adhesion between solids with rough surfaces is only possible if at least one of the solids is elastically very soft. Some lizards and spiders are able to adhere (dry adhesion) and move on very rough vertical surfaces due to very compliant surface layers on their attachment pads. Flies, bugs, grasshoppers and tree frogs have less compliant pad surface layers, and in these cases adhesion to rough surfaces is only possible because the animals inject a wetting liquid into the pad-substrate contact area, which generates a relative long-range attractive interaction due to the formation of capillary bridges. In this presentation I will discuss some aspects of wet adhesion for tree frogs and give some comments related to tire applications.

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

    CERN Document Server

    House, Donald

    1989-01-01

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

  18. Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens

    Science.gov (United States)

    Huang, Y.-W.; Hoffman, D.J.; Karasov, W.H.

    2007-01-01

    Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates

  19. Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

    Science.gov (United States)

    Fellers, G.M.; Green, E.D.; Longcore, J.E.

    2001-01-01

    The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658-3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

  20. Molecular phylogeny of microhylid frogs (Anura: Microhylidae) with emphasis on relationships among New World genera

    OpenAIRE

    de S?, Rafael O; Streicher, Jeffrey W; Sekonyela, Relebohile; Forlani, Mauricio C; Loader, Simon P; Greenbaum, Eli; Richards, Stephen; Haddad, C?lio F B

    2012-01-01

    Abstract Background Over the last ten years we have seen great efforts focused on revising amphibian systematics. Phylogenetic reconstructions derived from DNA sequence data have played a central role in these revisionary studies but have typically under-sampled the diverse frog family Microhylidae. Here, we present a detailed phylogenetic study focused on expanding previous hypotheses of relationships within this cosmopolitan family. Specifically, we placed an emphasis on assessing relations...

  1. Molecular phylogeny of microhylid frogs (Anura: Microhylidae) with emphasis on relationships among New World genera

    OpenAIRE

    de Sá R. O Streicher J. W. Sekonyela R. Forlani M. C. Loader S. P. Greenbaum E. Richards

    2012-01-01

    Abstract Background Over the last ten years we have seen great efforts focused on revising amphibian systematics. Phylogenetic reconstructions derived from DNA sequence data have played a central role in these revisionary studies but have typically under sampled the diverse frog family Microhylidae. Here we present a detailed phylogenetic study focused on expanding previous hypotheses of relationships within this cosmopolitan family. Specifically we placed an emphasis on assessing relationshi...

  2. New material of Beelzebufo, a hyperossified frog (Amphibia: Anura from the late cretaceous of Madagascar.

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    Susan E Evans

    Full Text Available 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.

  3. An elusive new species of Marsupial Frog (Anura: Hemiphractidae: Gastrotheca from the Andes of northern Peru

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    William E. Duellman

    2013-06-01

    Full Text Available A new species of marsupial frog, genus Gastrotheca, is described from high-elevation grasslands in the Andes in Región Amazonas in northernPeru, where even calling males are well hidden in deep moss. The new species is distinguished from all congeners by its unique color pattern that includes a narrow, blackbordered, yellow middorsal stripe. The species apparently belongs to the Gastrotheca plumbea Group, which ranges in the Andes from northern Colombia to northern Peru.

  4. Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns

    OpenAIRE

    Rojas Zuluaga, Bibiana

    2017-01-01

    The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal obs...

  5. A reference system for animal biometrics: application to the northern leopard frog

    Science.gov (United States)

    Petrovska-Delacretaz, D.; Edwards, A.; Chiasson, J.; Chollet, G.; Pilliod, D.S.

    2014-01-01

    Reference systems and public databases are available for human biometrics, but to our knowledge nothing is available for animal biometrics. This is surprising because animals are not required to give their agreement to be in a database. This paper proposes a reference system and database for the northern leopard frog (Lithobates pipiens). Both are available for reproducible experiments. Results of both open set and closed set experiments are given.

  6. Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens.

    Science.gov (United States)

    Huang, Yue-wern; Hoffman, David J; Karasov, William H

    2007-04-15

    Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates.

  7. Estimation of systemic catecholamine levels, in the Edible frog, using a radioenzymatic assay

    International Nuclear Information System (INIS)

    Bourgeois, Philippe; Dupont, Willy; Vaillant, Rene

    1978-01-01

    We have developed a radio-enzymatic assay for systemic catecholamines in the Frog. Such are its specificity and sensibility that adrenaline and noradrenaline may be measured in 50 μl of plasma samples, the withdrawal of which strongly influenced the results. The smaller values were obtained in plasma withdrawn from canulated animals. In this case, adrenaline was the major catecholamine in the plasma: 190 +- 55 ng/100 ml versus 35 +- 18 ng/100 ml for noradreline [fr

  8. The right thalamus may play an important role in anesthesia-awakening regulation in frogs

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    Yanzhu Fan

    2018-03-01

    Full Text Available Background Previous studies have shown that the mammalian thalamus is a key structure for anesthesia-induced unconsciousness and anesthesia-awakening regulation. However, both the dynamic characteristics and probable lateralization of thalamic functioning during anesthesia-awakening regulation are not fully understood, and little is known of the evolutionary basis of the role of the thalamus in anesthesia-awakening regulation. Methods An amphibian species, the South African clawed frog (Xenopus laevis was used in the present study. The frogs were immersed in triciane methanesulfonate (MS-222 for general anesthesia. Electroencephalogram (EEG signals were recorded continuously from both sides of the telencephalon, diencephalon (thalamus and mesencephalon during the pre-anesthesia stage, administration stage, recovery stage and post-anesthesia stage. EEG data was analyzed including calculation of approximate entropy (ApEn and permutation entropy (PE. Results Both ApEn and PE values differed significantly between anesthesia stages, with the highest values occurring during the awakening period and the lowest values during the anesthesia period. There was a significant correlation between the stage durations and ApEn or PE values during anesthesia-awakening cycle primarily for the right diencephalon (right thalamus. ApEn and PE values for females were significantly higher than those for males. Discussion ApEn and PE measurements are suitable for estimating depth of anesthesia and complexity of amphibian brain activity. The right thalamus appears physiologically positioned to play an important role in anesthesia-awakening regulation in frogs indicating an early evolutionary origin of the role of the thalamus in arousal and consciousness in land vertebrates. Sex differences exist in the neural regulation of general anesthesia in frogs.

  9. Vestigial preference functions in neural networks and túngara frogs.

    OpenAIRE

    Phelps, S. M.; Ryan, M. J.; Rand, A. S.

    2001-01-01

    Although there is a growing interest in understanding how perceptual mechanisms influence behavioral evolution, few studies have addressed how perception itself is shaped by evolutionary forces. We used a combination of artificial neural network models and behavioral experiments to investigate how evolutionary history influenced the perceptual processes used in mate choice by female túngara frogs. We manipulated the evolutionary history of artificial neural network models and observed an emer...

  10. Hybridization promotes color polymorphism in the aposematic harlequin poison frog, Oophaga histrionica

    OpenAIRE

    Medina, Iliana; Wang, Ian J; Salazar, Camilo; Amézquita, Adolfo

    2013-01-01

    Whether hybridization can be a mechanism that drives phenotypic diversity is a widely debated topic in evolutionary biology. In poison frogs (Dendrobatidae), assortative mating has been invoked to explain how new color morphs persist despite the expected homogenizing effects of natural selection. Here, we tested the complementary hypothesis that new morphs arise through hybridization between different color morphs. Specifically, we (1) reconstructed the phylogenetic relationships among the st...

  11. Female mate choice and the potential for ornament evolution in túngara frogs Physalaemus pustulosus

    OpenAIRE

    Michael J. RYAN, Ximena E. BERNA, A. Stanley RAND

    2010-01-01

    The potential for ornament evolution in response to sexual selection rests on the interaction between the permissiveness or selectivity of female preferences and the constraints on male development of signaling related traits. We investigate the former by determining how latent female preferences either exaggerate the magnitude of current traits (i.e. elaborations) or favor novel traits (i.e. innovations). In túngara frogs, females prefer complex mating calls (whine-chucks) to simple calls (...

  12. Mating status correlates with dorsal brightness in some but not all poison frog populations

    OpenAIRE

    Dreher, Corinna E.; Rodríguez, Ariel; Cummings, Molly E.; Pröhl, Heike

    2017-01-01

    Abstract Sexual signals are important for intraspecific communication and mate selection, but their evolution may be driven by both natural and sexual selection, and stochastic processes. Strawberry poison frogs (Oophaga pumilio) show strong color divergence among populations, but coloration also varies among individuals of the same population. The importance of coloration for female mate choice has been studied intensely, and sexual selection seems to affect color divergence in strawberry po...

  13. Underestimation of species richness in neotropical frogs revealed by mtDNA analyses.

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    Antoine Fouquet

    2007-10-01

    Full Text Available Amphibians are rapidly vanishing. At the same time, it is most likely that the number of amphibian species is highly underestimated. Recent DNA barcoding work has attempted to define a threshold between intra- and inter-specific genetic distances to help identify candidate species. In groups with high extinction rates and poorly known species boundaries, like amphibians, such tools may provide a way to rapidly evaluate species richness.Here we analyse published and new 16S rDNA sequences from 60 frog species of Amazonia-Guianas to obtain a minimum estimate of the number of undescribed species in this region. We combined isolation by distance, phylogenetic analyses, and comparison of molecular distances to evaluate threshold values for the identification of candidate species among these frogs.In most cases, geographically distant populations belong to genetically highly distinct lineages that could be considered as candidate new species. This was not universal among the taxa studied and thus widespread species of Neotropical frogs really do exist, contrary to previous assumptions. Moreover, the many instances of paraphyly and the wide overlap between distributions of inter- and intra-specific distances reinforce the hypothesis that many cryptic species remain to be described. In our data set, pairwise genetic distances below 0.02 are strongly correlated with geographical distances. This correlation remains statistically significant until genetic distance is 0.05, with no such relation thereafter. This suggests that for higher distances allopatric and sympatric cryptic species prevail. Based on our analyses, we propose a more inclusive pairwise genetic distance of 0.03 between taxa to target lineages that could correspond to candidate species.Using this approach, we identify 129 candidate species, two-fold greater than the 60 species included in the current study. This leads to estimates of around 170 to 460 frog taxa unrecognized in Amazonia

  14. Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: Implications for future monitoring

    Science.gov (United States)

    Chelgren, Nathan D.; Pearl, Christopher A.; Bowerman, Jay; Adams, Michael J.

    2007-01-01

    From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology. Movement rates revealed complementary use of sites seasonally, with one small spring being preferred during winter that was rarely used during the rest of the year. Growth rates were significantly higher in ponds that were not used for breeding, and larger size resulted in significantly higher survival. When variation in survival by size was accounted for there was little variation among ponds in survival. Seasonal estimates of survival were lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. Overwintering survival for both genders was relatively high. Our study supports others in suggesting Oregon spotted frogs are specific in their overwintering habitat requirements, and that predator-free springs may be of particular value. We suggest that any future monitoring include measures of the rate of pond succession. Demographic monitoring should include metrics of both frog reproduction and survival: counts of egg masses at all ponds during spring, and capture-recapture study of survival in mid and late summer when capture rates are highest. Additional study of early life stages would be particularly useful to broaden our understanding of the species’ ecology. Specifically, adding intensive capture and marking effort after larval transformation in fall would enable a full understanding of the annual life cycle. Complete study of the annual life cycle is needed to isolate the life stages and mechanisms through which Oregon spotted frogs are affected by stressors such as nonnative predators. Dilman Meadow, which lacks many hypothesized stressors, is an important reference for

  15. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs.

    Science.gov (United States)

    Coutinho, Selene Dall'Acqua; Burke, Julieta Catarina; de Paula, Catia Dejuste; Rodrigues, Miguel Trefaut; Catão-Dias, José Luiz

    2015-06-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.

  16. A philosophical approach to Emotions: understanding Love’s Knowledge through a Frog in Love

    OpenAIRE

    Murris, Karin

    2009-01-01

    In this paper I offer a philosophical approach to the emotion ‘love’, as a response to more psychological approaches presupposed in ‘emotional intelligence’, ‘emotional literacy’ programmes, or how some Philosophy for Children practitioners interpret ‘caring thinking’. Martha Nussbaum’s philosophy of emotions expressed in her book Love’s Knowledge, and the complex arguments contained within it have been given a narrative context: the picturebook Frog in Love by Max Velthuijs. The narrative co...

  17. [Biological testing of water with different structural states in rats and frogs].

    Science.gov (United States)

    Farashchuk, N F; Mikhaylova, R I; Telenkova, O G

    2014-01-01

    The effect of water samples with different structural states on some physiological indices of white laboratory rats, 5 groups of 10 animals (5 females and 5 males) and frogs has been studied. The investigation was performed for 1 month. For the determination of the content of liquid crystal associates (LCA) in water samples there was used the dilatometric method, the performance of experimental animals was studied by the swimming test (up to total fatigue). The performed experiment on growing rats with the use of water with varying degrees of structuredness showed that according to the weight gain there were optimal water "Lekor" and tap water, treated with Bioptron (the content of the structured fraction is 5.06 +/- 0.09% and 6.9 +/- 0.23%, respectively). On physical performance the best indices were in animals consumed water treated with the Bioptron lamp. In performance of experiments on frogs it was found that cardiac function in animals under experimental conditions over time weakens spontaneously: heart rate and cardiac output decline. Therefore, the effect of different water samples on the cardiac function was assessed on the intensity of its decrease for 15 minutes. In the experimental study of the effect of water with different content of LCA on heart rate and cardiac output of the frog it was found that the optimum level of structuredness of water is within the range of 5.06 +/- 0.09% (in water "Lekor") - 6.9 +/- 0.23% (tap water treated with Bioptron). All the other water samples, the content of nanocrystals in which was below or above this range, has a pronounced inhibitory effect on the heart performance of the frog.

  18. Developmental toxicity of two common corn pesticides to the endangered southern bell frog (Litoria raniformis)

    International Nuclear Information System (INIS)

    Choung, Catherine B.; Hyne, Ross V.; Mann, Reinier M.; Stevens, Mark M.; Hose, Grant C.

    2011-01-01

    To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 μg/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 μg/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides. - Highlights: → The effect of terbufos sulfone and atrazine on larval growth and development was investigated. → Terbufos sulfone alone significantly slowed development and delayed metamorphosis of tadpoles. → Atrazine had no observable effects alone nor did it interact synergistically with terbufos sulfone. → The developmental effects indicates a risk to endangered southern bell frogs in the irrigation area. → The results highlight the toxicological importance of some pesticide breakdown products. - A breakdown product of the insecticide terbufos retards development and delays metamorphosis of southern bell frog tadpoles.

  19. The First Call Note Plays a Crucial Role in Frog Vocal Communication.

    Science.gov (United States)

    Yue, Xizi; Fan, Yanzhu; Xue, Fei; Brauth, Steven E; Tang, Yezhong; Fang, Guangzhan

    2017-08-31

    Vocal Communication plays a crucial role in survival and reproductive success in most amphibian species. Although amphibian communication sounds are often complex consisting of many temporal features, we know little about the biological significance of each temporal component. The present study examined the biological significance of notes of the male advertisement calls of the Emei music frog (Babina daunchina) using the optimized electroencephalogram (EEG) paradigm of mismatch negativity (MMN). Music frog calls generally contain four to six notes separated approximately by 150 millisecond intervals. A standard stimulus (white noise) and five deviant stimuli (five notes from one advertisement call) were played back to each subject while simultaneously recording multi-channel EEG signals. The results showed that the MMN amplitude for the first call note was significantly larger than for that of the others. Moreover, the MMN amplitudes evoked from the left forebrain and midbrain were typically larger than those from the right counterpart. These results are consistent with the ideas that the first call note conveys more information than the others for auditory recognition and that there is left-hemisphere dominance for processing information derived from conspecific calls in frogs.

  20. Geological and climatic forces driving speciation in the continentally distributed trilling chorus frogs (Pseudacris).

    Science.gov (United States)

    Lemmon, Emily Moriarty; Lemmon, Alan R; Cannatella, David C

    2007-09-01

    Tertiary geological events and Quaternary climatic fluctuations have been proposed as important factors of speciation in the North American flora and fauna. Few studies, however, have rigorously tested hypotheses regarding the specific factors driving divergence of taxa. Here, we test explicit speciation hypotheses by correlating geologic events with divergence times among species in the continentally distributed trilling chorus frogs (Pseudacris). In particular, we ask whether marine inundation of the Mississippi Embayment, uplift of the Appalachian Mountains, or modification of the ancient Teays-Mahomet River system contributed to speciation. To examine the plausibility of ancient rivers causing divergence, we tested whether modern river systems inhibit gene flow. Additionally, we compared the effects of Quaternary climatic factors (glaciation and aridification) on levels of genetic variation. Divergence time estimates using penalized likelihood and coalescent approaches indicate that the major lineages of chorus frogs diversified during the Tertiary, and also exclude Quaternary climate change as a factor in speciation of chorus frogs. We show the first evidence that inundation of the Mississippi Embayment contributed to speciation. We reject the hypotheses that Cenozoic uplift of the Appalachians and that diversion of the Teays-Mahomet River contributed to speciation in this clade. We find that by reducing gene flow, rivers have the potential to cause divergence of lineages. Finally, we demonstrate that populations in areas affected by Quaternary glaciation and aridification have reduced levels of genetic variation compared to those from more equable regions, suggesting recent colonization.

  1. Effects of mosquitofish (Gambusia affinis cues on wood frog (Lithobates sylvaticus tadpole activity

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    Katherine F. Buttermore

    2011-06-01

    Full Text Available We examined the changes in activity of wood frog (Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish (Gambusia affinis. We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog (L. sylvaticus tadpoles was not affected by the presence of various cues from mosquitofish. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used. Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term. Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

  2. Effect of magnetic fields on green color formation in frog skin

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    H. Kashiwagi

    2017-05-01

    Full Text Available The present work is focused on a dynamic and efficient optical control system that is made possible by investigation of the body surfaces of various animals. Specifically, we expect Japanese tree frog (Hyla japonica skin to provide a model for a flexible display device actuator mechanism. Tree frogs change body color from their original green to other colors in response to background colors. The color formation is controlled not only by chromatophores, but also by guanine microcrystals in iridophores. We collected sample microcrystals from the frog’s dorsal skin and made a model display sheet using the green skin layers. The transparent chamber that contained the crystal suspension was layered to enhance light reflection. Sheet color was observed while the angle of light incidence was varied, with and without magnetic field exposure at 0.3 T. A slight increase in red and green intensity was detected. Additionally, reflected intensity increased with increasing angle of incidence. These results indicate that the guanine crystal platelets in frog skin can efficiently switch the reflected light direction under application of a magnetic field. This in turn suggests that a several-micron-sized microcrystal of this type is a candidate material for development of flexible optical chips for ambient light control.

  3. Oviduct modifications in foam-nesting frogs, with emphasis on the genus Leptodactylus (Amphibia, Leptodactylidae)

    Science.gov (United States)

    Furness, Andrew I.; McDiarmid, Roy W.; Heyer, W. Ronald; Zug, George R.

    2010-01-01

    Various species of frogs produce foam nests that hold their eggs during development. We examined the external morphology and histology of structures associated with foam nest production in frogs of the genus Leptodactylus and a few other taxa. We found that the posterior convolutions of the oviducts in all mature female foam-nesting frogs that we examined were enlarged and compressed into globular structures. This organ-like portion of the oviduct has been called a "foam gland" and these structures almost certainly produce the secretion that is beaten by rhythmic limb movements into foam that forms the nest. However, the label "foam gland" is a misnomer because the structures are simply enlarged and tightly folded regions of the pars convoluta of the oviduct, rather than a separate structure; we suggest the name pars convoluta dilata (PCD) for this feature. Although all the foam-nesters we examined had a pars convoluta dilata, its size and shape showed considerable interspecific variation. Some of this variation likely reflects differences in the breeding behaviors among species and in the size, type, and placement of their foam nests. Other variation, particularly in size, may be associated with the physiological periodicity and reproductive state of the female, her age, and/or the number of times she has laid eggs.

  4. A consistent nomenclature of antimicrobial peptides isolated from frogs of the subfamily Phyllomedusinae.

    Science.gov (United States)

    Amiche, Mohamed; Ladram, Ali; Nicolas, Pierre

    2008-11-01

    A growing number of cationic antimicrobial peptides have been isolated from the skin of hylid frogs belonging to the Phyllomedusinae subfamily. The amino acid sequences of these peptides are currently located in several databases under identifiers with no consistent system of nomenclature to describe them. In order to provide a workable terminology for antimicrobial peptides from Phyllomedusid frogs, we have made a systematic effort to collect, analyze, and classify all the Phyllomedusid peptide sequences available in databases. We propose that frogs belonging to the Phyllomedusinae subfamily should be described by the species names set out in Amphibian Species of the World: http://research.amnh.org/herpetology/amphibia/index.php, American Museum of Natural History, New York, USA. Multiple alignments analysis of at least 80 antimicrobial peptides isolated from 12 Phyllomedusinae species were distributed in seven distinct peptide families including dermaseptin, phylloseptin, plasticin, dermatoxin, phylloxin, hyposin and orphan peptides, and will be considered as the name of the headgroup of each family. The parent peptide's name should be followed by the first upper letter of the species for orthologous peptides and publication date determines priority. For example, the abbreviation B for bicolor and H for hypochondrialis. When two species begin with the same letter, two letters in upper case should be used (the first letter followed by the second or the third letter and so on). For example, the abbreviation DI for distincta, DU for duellmani, VA for vaillanti and VN for vanzolinii. Paralogous peptides should bear letter(s) in upper case followed by numbers.

  5. Shuffled Frog Leaping Algorithm for Preemptive Project Scheduling Problems with Resource Vacations Based on Patterson Set

    Directory of Open Access Journals (Sweden)

    Yi Han

    2013-01-01

    Full Text Available This paper presents a shuffled frog leaping algorithm (SFLA for the single-mode resource-constrained project scheduling problem where activities can be divided into equant units and interrupted during processing. Each activity consumes 0–3 types of resources which are renewable and temporarily not available due to resource vacations in each period. The presence of scarce resources and precedence relations between activities makes project scheduling a difficult and important task in project management. A recent popular metaheuristic shuffled frog leaping algorithm, which is enlightened by the predatory habit of frog group in a small pond, is adopted to investigate the project makespan improvement on Patterson benchmark sets which is composed of different small and medium size projects. Computational results demonstrate the effectiveness and efficiency of SFLA in reducing project makespan and minimizing activity splitting number within an average CPU runtime, 0.521 second. This paper exposes all the scheduling sequences for each project and shows that of the 23 best known solutions have been improved.

  6. Climatic influences on the breeding biology of the agile frog ( Rana dalmatina)

    Science.gov (United States)

    Combes, Magali; Pinaud, David; Barbraud, Christophe; Trotignon, Jacques; Brischoux, François

    2018-02-01

    Severe population declines of amphibians have been shown to be attributed to climate change. Nevertheless, the various mechanisms through which climate can influence population dynamics of amphibians remain to be assessed, notably to disentangle the relative synergetic or antagonistic influences of temperature and precipitations on specific life history stages. We investigated the impact of rainfall and temperature on the egg-clutch abundance in a population of agile frog ( Rana dalmatina) during 29 years (1987-2016) on 14 breeding sites located in Brenne Natural Park, France. Specifically, we examined the influence of environmental conditions occurring during five temporal windows of the year cycle corresponding to specific life history stages. Overall, our results suggest that the year-to-year fluctuations of egg-clutch abundances in Brenne Natural Park were partly dependent on local climatic conditions (rainfall and temperature). Climate seemed to influence breeding frogs during the autumn-winter period preceding reproduction. Spring and summer conditions did not influence reproduction. Additionally, we failed to detect effects of climatic conditions on newly metamorphosed individuals. Other factors such as density dependence and inter-specific interactions with introduced predators are likely to play a significant role in reproduction dynamics of the studied frog populations.

  7. When dinner is dangerous: toxic frogs elicit species-specific responses from a generalist snake predator.

    Science.gov (United States)

    Phillips, Ben; Shine, Richard

    2007-12-01

    In arms races between predators and prey, some evolved tactics are unbeatable by the other player. For example, many types of prey are inedible because they have evolved chemical defenses. In this case, prey death removes any selective advantage of toxicity to the prey but not the selective advantage to a predator of being able to consume the prey. In the absence of effective selection for postmortem persistence of the toxicity then, some chemical defenses probably break down rapidly after prey death. If so, predators can overcome the toxic defense simply by waiting for that breakdown before consuming the prey. Floodplain death adders (Acanthophis praelongus) are highly venomous frog-eating elapid snakes native to northern Australia. Some of the frogs they eat are nontoxic (Litoria nasuta), others produce gluelike mucus when seized by a predator (Limnodynastes convexiusculus), and one species (Litoria dahlii) is dangerously toxic to snakes. Both the glue and the toxin degrade within about 20 min of prey death. Adders deal with these prey types in different and highly stereotyped ways: they consume nontoxic frogs directly but envenomate and release the other taxa, waiting until the chemical defense loses its potency before consuming the prey.

  8. Thyrotropin-releasing hormone (TRH promotes wound re-epithelialisation in frog and human skin.

    Directory of Open Access Journals (Sweden)

    Natalia T Meier

    Full Text Available There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression. Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters.

  9. On the invasion of the parasitic fly Lucilia bufonivora (Diptera, Calliphoridae on the common frog

    Directory of Open Access Journals (Sweden)

    Lyabzina Svetlana

    2014-11-01

    Full Text Available Lucilia bufonivora is an obligate, specialised parasite of amphibians. Larval development takes place in the host body. The paper gives a detailed description of parasite observation. This observation was carried out beginning with the moment of finding larvae in the head of the frog till its death and adults flying out. Initially the larvae are located deep in the nostrils, occasionally crawling out on the head. In the frontal part of the frog’s head between the eyes, under the skin, they form a noticeable tubercle. The larvae in the head disturb the frog and lead to its death. After the death of the frog, the larvae move to the nostrils for time, filling them completely. In a day they destroy all soft tissues and cartilages of the host body. The development of larvae on the corpse continues for two days, then they move into the soil for pupation. Their puparia are located under the corpse at a depth of several centimeters. The adults fly out on the 10th day after their pupation. Of the 78 larvae found on the corpse, there were 59 flies, (31 females and 28 males.

  10. Selection on MHC class II supertypes in the New Zealand endemic Hochstetter's frog.

    Science.gov (United States)

    Lillie, Mette; Grueber, Catherine E; Sutton, Jolene T; Howitt, Robyn; Bishop, Phillip J; Gleeson, Dianne; Belov, Katherine

    2015-04-13

    The New Zealand native frogs, family Leiopelmatidae, are among the most archaic in the world. Leiopelma hochstetteri (Hochstetter's frog) is a small, semi-aquatic frog with numerous, fragmented populations scattered across New Zealand's North Island. We characterized a major histocompatibility complex (MHC) class II B gene (DAB) in L. hochstetteri from a spleen transcriptome, and then compared its diversity to neutral microsatellite markers to assess the adaptive genetic diversity of five populations ("evolutionarily significant units", ESUs). L. hochstetteri possessed very high MHC diversity, with 74 DAB alleles characterized. Extremely high differentiation was observed at the DAB locus, with only two alleles shared between populations, a pattern that was not reflected in the microsatellites. Clustering analysis on putative peptide binding residues of the DAB alleles indicated four functional supertypes, all of which were represented in 4 of 5 populations, albeit at different frequencies. Otawa was an exception to these observations, with only two DAB alleles present. This study of MHC diversity highlights extreme population differentiation at this functional locus. Supertype differentiation was high among populations, suggesting spatial and/or temporal variation in selection pressures. Low DAB diversity in Otawa may limit this population's adaptive potential to future pathogenic challenges.

  11. Reproductive phenology of the tomato frog, Dyscophus antongili, in an urban pond of Madagascar's east coast

    Directory of Open Access Journals (Sweden)

    Ori Segev

    2012-12-01

    Full Text Available Based on daily monitoring around an urban pond in the coastal town of Maroantsetra, from 2003-2011, we provide an analysis of the yearly reproductive activity of the tomato frog (Dyscophus antongilii, a large-sized and prominent red-coloured microhylid frog from north-eastern Madagascar. Frogs were observed all year round but despite the limited climatic seasonality in the region it was possible to identify a high activity period between January-May and a lower activity period between June-December. Freshly laid eggs were found in all months except November, and with highest incidence between January and May, while calling was heard in all months. We found a positive correlation between daily adult counts and minimum air temperature. On the contrary rainfall did not significantly predict activity, although boosts of calling and egg-laying especially in the austral winter were observed after heavy rainfall events. We define D. antongilii in Maroantsetra as a sporadic wet season breeder that reproduces at irregular intervals following heavy rain events.

  12. Multispecies benefits of wetland conservation for marsh birds, frogs, and species at risk.

    Science.gov (United States)

    Tozer, Douglas C; Steele, Owen; Gloutney, Mark

    2018-04-15

    Wetlands conserved using water level manipulation, cattle exclusion, naturalization of uplands, and other techniques under the North American Waterfowl Management Plan ("conservation project wetlands") are important for ducks, geese, and swans ("waterfowl"). However, the assumption that conservation actions for waterfowl also benefit other wildlife is rarely quantified. We modeled detection and occupancy of species at sites within 42 conservation project wetlands compared to sites within 52 similar nearby unmanaged wetlands throughout southern Ontario, Canada, and small portions of the adjacent U.S., using citizen science data collected by Bird Studies Canada's Great Lakes Marsh Monitoring Program, including 2 waterfowl and 13 non-waterfowl marsh-breeding bird species (n = 413 sites) and 7 marsh-breeding frog species (n = 191 sites). Occupancy was significantly greater at conservation project sites compared to unmanaged sites in 7 of 15 (47%) bird species and 3 of 7 (43%) frog species, with occupancy being higher by a difference of 0.12-0.38 across species. Notably, occupancy of priority conservation concern or at-risk Black Tern (Chlidonias niger), Common Gallinule (Gallinula galeata), Least Bittern (Ixobrychus exilis), Sora (Porzana carolina), and Western Chorus Frog (Pseudacris triseriata) was significantly higher at conservation project sites compared to unmanaged sites. The results demonstrate the utility of citizen science to inform wetland conservation, and suggest that actions under the North American Waterfowl Management Plan are effective for conserving non-waterfowl species. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Thyrotropin-Releasing Hormone (TRH) Promotes Wound Re-Epithelialisation in Frog and Human Skin

    Science.gov (United States)

    Zhang, Guo-You; Emelianov, Vladimir; Paredes, Roberto; Debus, Sebastian; Augustin, Matthias; Funk, Wolfgang; Amaya, Enrique; Kloepper, Jennifer E.; Hardman, Matthew J.; Paus, Ralf

    2013-01-01

    There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters. PMID:24023889

  14. Morphology and function of the forelimb in arboreal frogs: specializations for grasping ability?

    Science.gov (United States)

    Manzano, Adriana S; Abdala, Virginia; Herrel, Anthony

    2008-09-01

    Frogs are characterized by a unique morphology associated with their saltatory lifestyle. Although variation in the form and function of the pelvic girdle and associated appendicular system related to specialized locomotor modes such as swimming or burrowing has been documented, the forelimbs have typically been viewed as relatively unspecialized. Yet, previous authors have noted versatility in forelimb function among arboreal frogs associated with feeding. Here we study the morphology and function of the forelimb and hand during locomotion in two species of arboreal frogs (Litoria caerulea and Phyllomedusa bicolor). Our data show a complex arrangement of the distal forelimb and hand musculature with some notable differences between species. Analyses of high-speed video and video fluoroscopy recordings show that forelimbs are used in alternating fashion in a diagonal sequence footfall pattern and that the position of the hand is adjusted when walking on substrates of different diameters. Electromyographic recordings show that the flexors of the hand are active during substrate contact, suggesting the use of gripping to generate a stabilizing torque. Measurements of grasping forces in vivo and during stimulation experiments show that both species, are capable of executing a so-called power grip but also indicates marked differences between species, in the magnitude of forces generated. Stimulation experiments showed an increased control of digit flexion in the more specialized of the two species, allowing it to execute a precision grip paralleled only by that seen in primates.

  15. Inventory of the pool frog, newt and gulyxne in Forsmark 2012

    International Nuclear Information System (INIS)

    Collinder, Per

    2013-01-01

    On assignment from the Swedish Nuclear Fuel and Waste Management Co (SKB), Ekologigruppen AB carried out inventories of species populations during the summer of 2012. Species included in the study are described in three separate chapters of this report. The three species were pool frog Rana lessonae, great crested newt Triturus cristatus, and fen orchid Liparis loeselii. SKB will follow up the development of the local populations. Inventory of pool frogs are already a follow-up on a study carried out in 2011. Concern for these species is due to their protection within the EU system of species and habitat protection. Construction of the planned depository for used nuclear fuel will involve redirection of groundwater, which could potentially drain these wetlands. The three species pool frog, great crested newt and fen orchid are inventoried by well-documented procedures, which will allow repletion of the study at the same locals and according to the same methods during consequent years. The inventories are not complete in the sense that they would give number of individuals in a local population. Rather, the result should be regarded as an index for comparison and monitoring

  16. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-12-23

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

  17. Diversification of African tree frogs (genus Leptopelis) in the highlands of Ethiopia.

    Science.gov (United States)

    Reyes-Velasco, Jacobo; Manthey, Joseph D; Freilich, Xenia; Boissinot, Stéphane

    2018-05-01

    The frog genus Leptopelis is composed of ~50 species that occur across sub-Saharan Africa. The majority of these frogs are typically arboreal; however, a few species have evolved a fossorial lifestyle. Most species inhabit lowland forests, but a few species have adapted to high elevations. Five species of Leptopelis occupy the Ethiopian highlands and provide a good opportunity to study the evolutionary transition from an arboreal to a fossorial lifestyle, as well as the diversification in this biodiversity hot spot. We sequenced 14 nuclear and three mitochondrial genes, and generated thousands of SNPs from ddRAD sequencing to study the evolutionary relationships of Ethiopian Leptopelis. The five species of highland Leptopelis form a monophyletic group, which diversified during the late Miocene and Pliocene. We found strong population structure in the fossorial species L. gramineus, with levels of genetic differentiation between populations similar to those found between arboreal species. This could indicate that L. gramineus is a complex of cryptic species. We propose that after the original colonization of the Ethiopian highlands by the ancestor of the L. gramineus group, episodes of vicariance fragmented the ancestral populations of this group. We also report the re-evolution of arboreality in L. susanae, which evolved from a fossorial ancestor, a rare ecological switch in frogs that had previously been reported only once. © 2018 John Wiley & Sons Ltd.

  18. Ontogeny of the vertebral column of Eleutherodactylus johnstonei (Anura: Eleutherodactylidae) reveals heterochronies relative to metamorphic frogs.

    Science.gov (United States)

    Meza-Joya, Fabio Leonardo; Ramos-Pallares, Eliana Patricia; Ramírez-Pinilla, Martha Patricia

    2013-07-01

    Over the last century, the morphogenesis of the vertebral column has been considered as a highly conserved process among anurans. This statement is based on the study of few metamorphic taxa, ignoring the role of developmental mechanisms underlying the evolution of specialized life-histories. Direct development in anurans has been regarded as evolutionarily derived and involves developmental recapitulation and repatterning at different levels in all amphibian taxa studied so far. Herein, we analyze the vertebral column morphogenesis of the direct-developing frog Eleutherodactylus johnstonei, describing the sequence of chondrification and ossification, based on cleared and double-stained specimens from early stage embryos to adults. In general, our results show that the morphogenesis of the vertebral column in E. johnstonei recapitulates the ancestral tadpole-like pattern of development. However, the analysis of the sequence of events using heterochrony plots shows important heterocronies relative to metamorphic species, such as a delay in the chondrification of the vertebral centra and in osteogenesis. These ontogenetic peculiarities may represent derived traits in direct-developing frogs and are possibly correlated with its unusual life history. In addition, several features of the vertebral column of E. johnstonei are highly variable from its typical morphology. We report some malformations and small deviations, which do not seem to affect the survival of individuals. These anomalies have also been found in other frogs, and include many vertebral defects, such as vertebral fusion, and vertebral preclusion and/or induction. Copyright © 2013 Wiley Periodicals, Inc.

  19. Correlates of virulence in a frog-killing fungal pathogen: evidence from a California amphibian decline.

    Science.gov (United States)

    Piovia-Scott, Jonah; Pope, Karen; Worth, S Joy; Rosenblum, Erica Bree; Poorten, Thomas; Refsnider, Jeanine; Rollins-Smith, Louise A; Reinert, Laura K; Wells, Heather L; Rejmanek, Dan; Lawler, Sharon; Foley, Janet

    2015-07-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines.

  20. Population recovery following decline in an endangered stream-breeding frog (Mixophyes fleayi from subtropical Australia.

    Directory of Open Access Journals (Sweden)

    David Alan Newell

    Full Text Available Amphibians have undergone dramatic declines and extinctions worldwide. Prominent among these have been the stream-breeding frogs in the rainforests of eastern Australia. The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has been postulated as the primary cause of these declines. We conducted a capture-mark-recapture study over a 7-year period on the endangered Fleay's barred frog (Mixophyes fleayi at two independent streams (30 km apart in order to assess the stability of these populations. This species had undergone a severe decline across its narrow geographic range. Mark-recapture modelling showed that the number of individuals increased 3-10 fold along stream transects over this period. Frog detection probabilities were frequently above 50% but declined as the populations increased. Adult survival was important to overall population persistence in light of low recruitment events, suggesting that longevity may be a key factor in this recovery. One male and female were present in the capture record for >6 years. This study provides an unambiguous example of population recovery in the presence of Bd.

  1. Developmental toxicity of two common corn pesticides to the endangered southern bell frog (Litoria raniformis)

    Energy Technology Data Exchange (ETDEWEB)

    Choung, Catherine B., E-mail: Catherine.Choung@mq.edu.au [Department of Biological Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, Office of Environment and Heritage, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Environmental Sustainability, University of Technology - Sydney, PO Box 123, Broadway, NSW 2007 (Australia); Stevens, Mark M. [EH Graham Centre for Agricultural Innovation (Industry and Investment NSW and Charles Sturt University), Yanco Agricultural Institute, Private Mail Bag, Yanco, NSW 2703 (Australia); Hose, Grant C. [Department of Biological Sciences, Macquarie University, Sydney, NSW 2109 (Australia)

    2011-10-15

    To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 {mu}g/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 {mu}g/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides. - Highlights: > The effect of terbufos sulfone and atrazine on larval growth and development was investigated. > Terbufos sulfone alone significantly slowed development and delayed metamorphosis of tadpoles. > Atrazine had no observable effects alone nor did it interact synergistically with terbufos sulfone. > The developmental effects indicates a risk to endangered southern bell frogs in the irrigation area. > The results highlight the toxicological importance of some pesticide breakdown products. - A breakdown product of the insecticide terbufos retards development and delays metamorphosis of southern bell frog tadpoles.

  2. Effects of oil sands waste water on the wood frog (rana sylvatica)

    Energy Technology Data Exchange (ETDEWEB)

    Hersikorn, B.; Smits, J.E. [Saskatchewan Univ., Regina, SK (Canada)

    2007-07-01

    The sustainability of various reclamation strategies can be determined by the growth and health of indigenous amphibians (Wood Frogs). This paper referred to the large quantities of tailings water that are generated by oil sand extraction activities. It presented the results of a study that was conducted in the spring and summer of 2006 and 2007 on reclaimed formation wetlands comprising tailings water. The objective was to understand the impact of these wetlands on native amphibians. Frogs were exposed to wetlands containing oil sands process affected water (OSPW) and reference water (no OSPW). Six experimental trenches were made at one site in the first year. Each trench had 3 enclosures with 50 tadpoles. In the second year, there were 13 sites, including 6 reference and 7 OSPW affected sites, which were classified as old (more than 8 yrs) or young (less than 7 yrs). Four enclosures, with 50 tadpoles each, were placed in each wetland. The study involved the evaluation of growth rate, survival, time to metamorphosis, thyroid hormone concentrations, liver EROD activity, and tissue retinol concentrations. In addition, stable isotopes were used to track carbon flow from primary production plants, through the food chain, to tadpoles and frogs which represent intermediate and higher trophic levels in reclaimed wetlands.

  3. Differential uptake of gold nanoparticles by 2 species of tadpole, the wood frog (Lithobates sylvaticus) and the bullfrog (Lithobates catesbeianus).

    Science.gov (United States)

    Thompson, Lucas B; Carfagno, Gerardo L F; Andresen, Kurt; Sitton, Andrea J; Bury, Taylor; Lee, Laura L; Lerner, Kevin T; Fong, Peter P

    2017-12-01

    Engineered nanoparticles are aquatic contaminants of emerging concern that exert ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide-capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 d, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls. The rank order of weight-normalized gold uptake was wood frogs in combination > wood frogs alone > bullfrogs in combination > bullfrogs alone > controls. In all gold-exposed groups of tadpoles, gold was concentrated in the anterior region compared with the posterior region of the body. The concentration of gold nanoparticles in the anterior region of wood frogs both alone and in combination with bullfrogs was significantly higher than the corresponding posterior regions. We also measured depuration time of gold in wood frogs. After 21 d in a solution of gold nanoparticles, tadpoles lost >83% of internalized gold when placed in gold-free water for 5 d. After 10 d in gold-free water, tadpoles lost 94% of their gold. After 15 d, gold concentrations were below the level of detection. Our finding of differential uptake between closely related species living in similar habitats with overlapping geographical distributions argues against generalizing toxicological effects of nanoparticles for a large group of organisms based on measurements in only one species. Environ Toxicol Chem 2017;36:3351-3358. © 2017 SETAC. © 2017 SETAC.

  4. Comparative pathology and ecological implications of two myxosporean parasites in native Australian frogs and the invasive cane toad.

    Directory of Open Access Journals (Sweden)

    Ashlie Hartigan

    Full Text Available Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60 tadpoles and (3/9 adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis were observed in the brains of threatened Southern bell frogs (8/8, critically endangered Booroolong frogs (15/44 and Yellow spotted bell frogs (3/3. Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72 Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered, suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA. Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in

  5. Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks

    Directory of Open Access Journals (Sweden)

    Robert B. Suter

    2003-07-01

    Full Text Available Fishing spiders (Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana and green frogs (R. clamitans on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances, rearing the legs nearest the attacking frog (N=15, 29.4%, or showing no visible response (N=7, 13.7%. Spiders that jumped always did so away (in the vertical plane from the attack (mean =137° vs. vertical at 90° or horizontally toward the frog at 0°. The involvement of the trichobothria (leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack.

  6. Experimental Repatriation of Mountain Yellow-legged Frogs (Rana muscosa) in the Sierra Nevada of California

    Science.gov (United States)

    Fellers, Gary M.; Bradford, David F.; Pratt, David; Wood, Leslie

    2008-01-01

    In the late 1970s, Rana muscosa (mountain yellow-legged frog) was common in the Tableland area of Sequoia National Park, California where it was possible to find hundreds of tadpoles and adults around many of the ponds and lakes. Surveys in 1993-1995 demonstrated that R. muscosa was absent from more than half of all suitable habitat within the park, including the Tableland area. At that same time, R. muscosa was still common at Sixty Lake Basin, Kings Canyon National Park, 30 km to the northeast. To evaluate the potential causes for the extirpation, we repatriated R. muscosa eggs, tadpoles, subadults, and adult frogs from Sixty Lake Basin to four sites in the Tableland area in 1994 and 1995. We subsequently surveyed each release site and the surrounding area 2 - 3 times per week in 1994-1995, and intermittently in 1996-1997, to monitor the survival of all life history stages, and to detect dispersal of adults and subadults. We also monitored predation, water quality, weather, and water temperature. Our techniques for capturing, holding, transporting, and releasing R. muscosa were refined during the study, and during 1995 resulted in high initial survival rates of all life history stages. Adult frogs were anaesthetized, weighed, measured, tagged, and held in plastic boxes with wet paper towels. Tadpoles were collected and held in fiberglass screen cages set in the water at the edge of a pond. This resulted in relatively natural conditions with less crowding and good water circulation. Frogs, tadpoles, and eggs were placed in Ziploc bags for transport to the Tableland by helicopter. Short-term survival of tadpoles, subadults, and adults was high at all four release sites, tadpoles reached metamorphosis, and adult frogs were still present. However, we detected no evidence of reproduction at three sites (e.g., no new eggs or small tadpoles) and nearly all life history stages disappeared within 12 months. At the fourth site, there was limited reproduction, but it was

  7. Adaptive plasticity of skeletal muscle energetics in hibernating frogs: mitochondrial proton leak during metabolic depression.

    Science.gov (United States)

    Boutilier, Robert G; St-Pierre, Julie

    2002-08-01

    The common frog (Rana temporaria) spends the coldest months of each year overwintering in ice-covered ponds where temperatures can vary from 0.5 to 4.0 degrees C. Over the course of a winter season, the animals enter progressively into a state of metabolic depression that relies almost exclusively on aerobic production of ATP. However, if aerobic metabolism is threatened, for example by increasingly hypoxic conditions, decreases in the animal's metabolic rate can reach upwards of 75% compared with the 50% decrease seen during normoxia. Under these conditions, the major proportion of the overall reduction in whole-animal metabolic rate can be accounted for by metabolic suppression of the skeletal muscle (which makes up approximately 40% of body mass). Little is known about the properties of mitochondria during prolonged periods of metabolic depression, so we have examined several aspects of mitochondrial metabolism in the skeletal muscle of frogs over periods of hibernation of up to 4 months. Mitochondria isolated from the skeletal muscle of frogs hibernating in hypoxic water show a considerable reorganisation of function compared with those isolated from normoxic submerged animals at the same temperature (3 degrees C). Both the active (state 3) and resting (state 4) respiration rates of mitochondria decrease during hypoxic, but not normoxic, hibernation. In addition, the affinity of mitochondria for oxygen increases during periods of acute hypoxic stress during normoxic hibernation as well as during long-term hibernation in hypoxic water. The decrease in mitochondrial state 4 respiration rates during hypoxic hibernation evidently occurs through a reduction in electron-transport chain activity, not through a lowered proton conductance of the mitochondrial inner membrane. The reduced aerobic capacity of frog skeletal muscle during hypoxic hibernation is accompanied by lowered activities of key enzymes of mitochondrial metabolism caused by changes in the intrinsic

  8. Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands

    Science.gov (United States)

    Bulger, J.B.; Scott, N.J.; Seymour, R.B.

    2003-01-01

    The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the adult population was resident at these sites. Adequate protection of red-legged frog populations inhabiting

  9. Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.

    Science.gov (United States)

    Naito, Risa; Yamasaki, Michimasa; Lmanishi, Ayumi; Natuhara, Yosihiro; Morimoto, Yukihiro

    2012-09-01

    In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species.

  10. Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa is effective in avoiding predation by snakes.

    Directory of Open Access Journals (Sweden)

    Yuri Yoshimura

    Full Text Available The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

  11. The effects of four arthropod diets on the body and organ weights of the leopard frog, Rana pipiens, during vitellogenesis.

    Science.gov (United States)

    Lehman, G C

    1978-12-01

    Wild-caught adult Rana pipiens females were captured in midsummer and fed diets of crickets, flies sowbugs or wax moth larvae during a three-month period of active vitellogenesis. The cricket diet supported the most extensive body weight gain during this time and promoted a prolonged period of weight increase in an additional long-term study. Synchronous growth of the oocytes occurred in all four groups, but the ovaries and oviducts of cricket-fed animals were significantly larger than those of frogs on the other three diets. The significantly higher liver weights of frogs fed wax moth larvae may have reflected an augmentation of hepatic energy stores. Fat body weights were also highest in this group of animals. Frogs fed crickets and wax moth larvae possessed larger fat bodies than did the midsummer control animals killed immediately after their arrival in the laboratory. In contrast, frogs fed flies and sowbugs had smaller fat bodies than did the initial controls, suggesting that animals on these diets had utilized fat body lipid during vitellogenesis. Gastrocnemius and final body weights were lowest in frogs fed wax moth larvae. These findings may have reflected the nutritional content of the diet or the reduction in appetite frequently noted in these animals during observations of feeding behavior.

  12. Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa) is effective in avoiding predation by snakes.

    Science.gov (United States)

    Yoshimura, Yuri; Kasuya, Eiiti

    2013-01-01

    The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

  13. Discovery of alien water frogs (gen. Pelophylax in Umbria, with first report of P. shqipericus for Italy

    Directory of Open Access Journals (Sweden)

    Dario Domeneghetti

    2013-12-01

    Full Text Available Allochthonous water frogs (gen. Pelophylax have been repeatedly introduced in several European countries, causing dramatic consequences for the conservation of indigenous taxa. In Italy, invasive populations are known for northern regions, where they were introduced mainly for edible and scientific purposes. Here, we report the first detection of an alien population of water frogs in Central Italy, along the Resina valley (Umbria. Genetic analysis of the mitochondrial ND3 gene polymorphism assigned some specimens to two different Pelophylax ridibundus clades widespread in Central and Eastern Europe. By contrast, two samples matched the mitochondrial DNA (mtDNA sequence of Pelophylax lessonae bergeri, an autochthonous taxon widespread in Central Italy, suggesting possible hybridization between alien and indigenous frogs. Finally, the specific haplotype of Pelophylax shqipericus, the Albanian Pool Frog, was also identified according to mtDNA polymorphism. This record, firstly reported for Italy, poses concerns for the conservation of this cryptic taxon, suggesting that international water frog trade may involve also particularly endangered species.

  14. Variable Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio are Perceived as Differences in Palatability to Arthropods.

    Science.gov (United States)

    Bolton, Sarah K; Dickerson, Kelsie; Saporito, Ralph A

    2017-03-01

    Conspicuously colored dendrobatid frogs sequester alkaloid defenses from dietary arthropods, resulting in considerable alkaloid variation among populations; however, little is known about how variation is perceived as a defense against predators. Previous studies have found variable alkaloids in the dendrobatid Oophaga pumilio to be associated with differences in toxicity to laboratory mice, suggesting variable defenses are important. Arthropods are natural predators that use chemoreception to detect prey, including frogs, and may therefore perceive variation in alkaloid profiles as differences in palatability. The goal of the present study is to determine how arthropods respond to variable alkaloid defenses in O. pumilio. Frog alkaloids were sampled from individual O. pumilio from ten geographic locations throughout the Bocas del Toro region of Panama and the Caribbean coast of Costa Rica. Alkaloid extracts were used in feeding bioassays with the vinegar fly Drosophila melanogaster and the ant Ectatomma ruidum. Both species of arthropods fed significantly less on frog alkaloid extracts when compared to controls, and differences in alkaloid palatability were observed among frog populations, as well as between sexes and life stages within a population. Differences in alkaloid quantity, richness, and type were the main predictors of arthropod palatability. Our findings also represent the first direct evidence of a palatability spectrum in a vertebrate that sequesters chemical defenses from dietary sources. Further, the presence of a palatability spectrum suggests that variable alkaloid defenses in O. pumilio are ecologically relevant and play an important role in natural predator-prey interactions, particularly with respect to arthropod predators.

  15. Whole-genome sequence of the Tibetan frog Nanorana parkeri and the comparative evolution of tetrapod genomes.

    Science.gov (United States)

    Sun, Yan-Bo; Xiong, Zi-Jun; Xiang, Xue-Yan; Liu, Shi-Ping; Zhou, Wei-Wei; Tu, Xiao-Long; Zhong, Li; Wang, Lu; Wu, Dong-Dong; Zhang, Bao-Lin; Zhu, Chun-Ling; Yang, Min-Min; Chen, Hong-Man; Li, Fang; Zhou, Long; Feng, Shao-Hong; Huang, Chao; Zhang, Guo-Jie; Irwin, David; Hillis, David M; Murphy, Robert W; Yang, Huan-Ming; Che, Jing; Wang, Jun; Zhang, Ya-Ping

    2015-03-17

    The development of efficient sequencing techniques has resulted in large numbers of genomes being available for evolutionary studies. However, only one genome is available for all amphibians, that of Xenopus tropicalis, which is distantly related from the majority of frogs. More than 96% of frogs belong to the Neobatrachia, and no genome exists for this group. This dearth of amphibian genomes greatly restricts genomic studies of amphibians and, more generally, our understanding of tetrapod genome evolution. To fill this gap, we provide the de novo genome of a Tibetan Plateau frog, Nanorana parkeri, and compare it to that of X. tropicalis and other vertebrates. This genome encodes more than 20,000 protein-coding genes, a number similar to that of Xenopus. Although the genome size of Nanorana is considerably larger than that of Xenopus (2.3 vs. 1.5 Gb), most of the difference is due to the respective number of transposable elements in the two genomes. The two frogs exhibit considerable conserved whole-genome synteny despite having diverged approximately 266 Ma, indicating a slow rate of DNA structural evolution in anurans. Multigenome synteny blocks further show that amphibians have fewer interchromosomal rearrangements than mammals but have a comparable rate of intrachromosomal rearrangements. Our analysis also identifies 11 Mb of anuran-specific highly conserved elements that will be useful for comparative genomic analyses of frogs. The Nanorana genome offers an improved understanding of evolution of tetrapod genomes and also provides a genomic reference for other evolutionary studies.

  16. Analysis of skin derived peptides from the Cuyaba Dwarf Frog Physalaemus nattereri by off-line LC MALDI MS/MS

    DEFF Research Database (Denmark)

    Castro, Mariana S; Pires Júnior, Osmindo Rodrigues; Fontes, Wagner

    2017-01-01

    We have investigated the potential for analysis of the complex peptide mixtures secreted from frog skin using off-line LC-MALDI MS/MS. Since only limited information about the sequence of such peptides is available, de novo sequencing followed by Blast search was needed. An automated workflow has...... for future studies of peptides secreted from frogs....

  17. Movement ecology and seasonal distribution of mountain yellow-legged frogs, Rana muscosa, in a high-elevation Sierra Nevada basin.

    Science.gov (United States)

    K.L. Pope; K.R. Matthews

    2001-01-01

    Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven...

  18. The Effect of Heat Treatment on Microstructure and Mechanical Properties of Cast Bainitic Steel Used for Frogs in Railway Crossovers

    Directory of Open Access Journals (Sweden)

    Parzych S.

    2017-12-01

    Full Text Available This work deals with the effect of heat treatment on a microstructure and mechanical properties of a selected cast steel assigned as a material used for frogs in railway crossovers. Materials used nowadays in the railway industry for frogs e.g. Hadfield cast steel (GX120Mn13 or wrougth pearlitic steel (eg. R260 do not fulfil all exploitation requirements indicated in the UIC (International Union of Railways Decision No. 1692/96 in terms of train speed that should be reached on railways. One of the possible solution is using a cast steel with bainitic or bainitic-martensitic microstructure that allows to gain high strength properties the ultimate tensile strength (UTS of 1400 MPa, the tensile yield strength (TYS of 900 MPa and the hardness of up to 400 BHN. The tested material is considered as an alternative to Hadfield cast steel that is currently used for railway frogs.

  19. Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

    Energy Technology Data Exchange (ETDEWEB)

    Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate `Filippo Bottazzi`

    1997-12-31

    Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

  20. Helminth communities of two green frogs (Rana perezi and Rana saharica from both shores of the Alboran Sea

    Directory of Open Access Journals (Sweden)

    Navarro P.

    2006-12-01

    Full Text Available The helminth communities of two populations of green frogs from both shores of the Alborán Sea (Western Mediterranean were studied. Of the 79 frogs examined for helminths, 39 individuals of the species Rana saharica were collected from Bab-Taza (Morocco, and 40 of the species Rana perezi were collected from the Natural Park of the Sierra de Grazalema (Spain. Although the species richness of helminths was identical in the two sampled areas, the differences observed in the structure of the helminth infracommunities were quite important. Statistically, significant differences were found between the species richness and the diversity of the infracommunities of R. perezi female population and the other three studied statistical populations. The helminth component communities of these two green frogs can be considered as depauperate, although their infracommunities present interactive features.

  1. Allozyme comparison of three Trypanosoma species (Kinetoplastida: Trypanosomatidae) of toads and frogs by starch-gel electrophoresis.

    Science.gov (United States)

    Martin, D S; Desser, S S; Hong, H

    1992-04-01

    Six metabolic enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, phosphoglucomutase, and purine nucleoside phosphorylase, from clonal isolates of 3 presumptive species of Trypanosoma (T. fallisi, T. ranarum, and T. rotatorium) from 3 anuran hosts (Bufo americanus, Rana clamitans, and Rana catesbeiana) were compared using starch-gel electrophoresis. Although bands were shared among the different zymodemes of isolates of the same host genus, low genetic polymorphism of the enzyme loci was observed with few apparent shared bands between samples isolated from frogs and toads. A distance value calculated between toad and frog trypanosome isolates suggests the likelihood of long-time separation of species. Cluster analysis based on overall similarity distinguished the trypanosomes of toads and frogs as separate taxa, suggesting that host specificity and observed morphological differences are consistent with heritable allozyme differences.

  2. Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

    Energy Technology Data Exchange (ETDEWEB)

    Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate ` Filippo Bottazzi`

    1998-12-31

    Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

  3. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun, E-mail: zhanghangjun@gmail.com

    2014-10-15

    Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations.

  4. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

    International Nuclear Information System (INIS)

    Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun

    2014-01-01

    Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations

  5. Peptidomic analysis of skin secretions supports separate species status for the tailed frogs, Ascaphus truei and Ascaphus montanus

    Science.gov (United States)

    Conlon, J.M.; Bevier, C.R.; Coquet, L.; Leprince, J.; Jouenne, T.; Vaudry, H.; Hossack, B.R.

    2007-01-01

    The tailed frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue and Wallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the products of orthologous ascaphin genes in electrically-stimulated skin secretions from inland range specimens. Structural characterization of the peptides demonstrated that ascaphins from the inland range contained the following amino acid substitutions compared with orthologs from the coastal range frogs: ascaphin-1 (Ala12 → Glu), ascaphin-3 (Asp4 → Glu), ascaphin-4 (Ala19 → Ser), ascaphin-5 (Lys12 → Thr), and ascaphin-7 (Gly8 → Ser and Ser20 → Asn). Orthologs of ascaphins-2, -6, and -8 were not identified but a paralog of ascaphin-5, identical to ascaphin-5 from coastal range frogs, was found. The data support the claims, derived from analysis of the nucleotide sequences of mitochondrial genes, that the inland populations of the tailed frog should be recognized as a distinct species, the Rocky Mountain tailed frog Ascaphus montanus and that the divergence of the species from A. truei probably occurred in the late Miocene (approximately 10 Mya).

  6. Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

    Directory of Open Access Journals (Sweden)

    Rodrigo B Ferreira

    Full Text Available Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i 200 m inside the forest, ii 50 m inside the forest, iii at the forest edge, and iv 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types. By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog

  7. Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

    Science.gov (United States)

    Ferreira, Rodrigo B; Beard, Karen H; Crump, Martha L

    2016-01-01

    Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest edge, and iv) 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types). By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders) was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm) and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in

  8. A survey of blood and other tissue parasites of leopard frogs Rana pipiens in the United States.

    Science.gov (United States)

    Levine, N D; Nye, R R

    1977-01-01

    In a survey of blood and other tissue parasites from 137 leopard frogs, Rana pipiens complex, purchased from 13 commercial vendors in 8 states in the United States, Trypanosoma pipientis was found in 2 R. p. berlandieri, Toxoplasma ranae in 1 R. pipiens, Isospora lieberkuehni in 1 leopard frog, Haemogregarina magna in 44, Lankesterella minima in 3, Leptotheca ohlmacheri in 3 and microfilariae of Foleyella sp. in 6. The report of I. lieberkuehni is presumably a new host record. Haemogregarina temporariae (Nöller,, 1920) nov. comb. is established as a new combination for Nematopsis temporariae.

  9. Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

    Science.gov (United States)

    Pfeiler, E; Markow, T A

    2008-10-01

    Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives.

  10. The Pharmacokinetics of Enrofloxacin in Adult African Clawed Frogs (Xenopus laevis)

    Science.gov (United States)

    Howard, Antwain M; Papich, Mark G; Felt, Stephen A; Long, Charles T; McKeon, Gabriel P; Bond, Emmitt S; Torreilles, Stéphanie L; Luong, Richard H; Green, Sherril L

    2010-01-01

    Pharmacokinetics of enrofloxacin, a fluoroquinolone antibiotic, was determined in adult female Xenopus laevis after single-dose administration (10 mg/kg) by intramuscular or subcutaneous injection. Frogs were evaluated at various time points until 8 h after injection. Plasma was analyzed for antibiotic concentration levels by HPLC. We computed pharmacokinetic parameters by using noncompartmental analysis of the pooled concentrations (naive pooled samples). After intramuscular administration of enrofloxacin, the half-life was 5.32 h, concentration maximum was 10.85 µg/mL, distribution volume was 841.96 mL/kg, and area under the time–concentration curve was 57.59 µg×h/mL; after subcutaneous administration these parameters were 4.08 h, 9.76 µg/mL, 915.85 mL/kg, and 47.42 µg×h/mL, respectively. According to plasma pharmacokinetics, Xenopus seem to metabolize enrofloxacin in a manner similar to mammals: low levels of the enrofloxacin metabolite, ciprofloxacin, were detected in the frogs’ habitat water and plasma. At necropsy, there were no gross or histologic signs of toxicity after single-dose administration; toxicity was not evaluated for repeated dosing. The plasma concentrations reached levels considered effective against common aquatic pathogens and suggest that a single, once-daily dose would be a reasonable regimen to consider when treating sick frogs. The treatment of sick frogs should be based on specific microbiologic identification of the pathogen and on antibiotic susceptibility testing. PMID:21205443

  11. Ovarian hyperstimulation syndrome in gonadotropin-treated laboratory South African clawed frogs (Xenopus laevis).

    Science.gov (United States)

    Green, Sherril L; Parker, John; Davis, Corrine; Bouley, Donna M

    2007-05-01

    Ovarian hyperstimulation syndrome (OHS) is a rare but sometimes fatal iatrogenic complication of ovarian stimulation associated with the administration of exogenous gonadotropins to women undergoing treatment for infertility. Laboratory Xenopus spp are commonly treated with human chorionic gonadotropin (hCG) to stimulate ovulation and optimize the number of oocytes harvested for use in biomedical research. Here we report cases of OHS in 2 gonadotropin-treated laboratory Xenopus laevis. After receiving hCG, the frogs developed severe subcutaneous accumulation of fluid, coelomic distention, and whole-body edema and were unable to dive, although they continued to eat and swim. At postmortem examination, extensive subcutaneous edema was present; ascites and massive numbers of free-floating eggs were found in the coelomic cavity and in aberrant locations: around the heart-sac and adhered to the liver capsule. Whole-body edema, gross enlargement of the ovaries, ascites, and abdominal distention are findings comparable to those observed in women with OHS. The pathophysiology of OHS is thought to be related to hormonally induced disturbances of vasoactive mediators, one of which may be vascular endothelial growth factor secreted by theca and granulosa cells. We know of no other report describing OHSlike symptoms in gonadotropin-treated frogs, and the cases described here are 2 of the 3 we have observed at our respective institutions over the last 6 y. According to these results, OHS appears to be rare in gonadotropin-treated laboratory Xenopus. However, the condition should be included in the differential diagnosis for the bloated frog.

  12. The morphology and attachment of Protopolystoma xenopodis (Monogenea: Polystomatidae infecting the African clawed frog Xenopus laevis

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    Theunissen Maxine

    2014-01-01

    Full Text Available The African clawed frog Xenopus laevis (Anura: Pipidae is host to more than 25 parasite genera encompassing most of the parasitic invertebrate groups. Protopolystoma xenopodis Price, 1943 (Monogenea: Polystomatidae is one of two monogeneans infecting X. laevis. This study focussed on the external morphology of different developmental stages using scanning electron microscopy, histology and light microscopy. Eggs are released continuously and are washed out when the frog urinates. After successful development, an active swimming oncomiracidium leaves the egg capsule and locates a potential post-metamorphic clawed frog. The oncomiracidium migrates to the kidney where it attaches and starts to feed on blood. The parasite then migrates to the urinary bladder where it reaches maturity. Eggs are fusiform, about 300 μm long, with a smooth surface and are operculated. Oncomiracidia are elongated and cylindrical in shape, with an oval posterior cup-shaped haptor that bears a total of 20 sclerites; 16 marginal hooklets used for attachment to the kidney of the host and two pairs of hamulus primordia. Cilia from the 64 ciliated cells enable the oncomiracidium to swim for up to 24 h when the cilia subsequently curl up, become non-functional and are shed from the body. The tegument between the ciliated cells bears a series of sensory papillae. The body of the mature parasite is elongated and pyriform and possesses an opisthaptor armed with three pairs of suckers and two pairs of falciform hooks to ensure a firm grip on the flexible internal surface of the urinary bladder.

  13. Sexual and somatic development of wood frog tadpoles along a thermal gradient.

    Science.gov (United States)

    Lambert, Max R; Smylie, Meredith S; Roman, Amber J; Freidenburg, L Kealoha; Skelly, David K

    2018-02-01

    All amphibian species are known to have genetic sex determination. However, a variety of environmental conditions can moderate sexual differentiation, in some cases leading to sex reversal and skewed sex ratios. While there has been a recent focus on chemically-induced sex reversal in amphibians, temperature can also influence sexual differentiation. Building upon a classic 1929 study by Emil Witschi, we assessed temperature-mediated sex reversal. Witschi found that the wood frog sex ratio is 100% male at a high temperature (32°C) compared to a 50:50 sex ratio at 20°C. This pattern is consistent with multiple models of environmentally mediated sexual differentiation in vertebrates. To better understand thermally mediated sex reversal, we raised wood frogs at temperature increments of ∼1°C between 19 and 34°C. Mirroring earlier findings, wood frog metamorph sex ratios are indistinguishable from 50:50 at the lowest temperature and entirely male at the highest temperatures. In between, sex ratios become increasingly male-dominated as temperatures increase, implying a steadily increasing tendency toward female-to-male sex reversal in warmer environments. There was no evidence of a threshold temperature effect on reversal patterns. We also show that, compared to males, females metamorphose larger and later in cooler conditions but earlier and smaller under warmer conditions. While the ecological relevance in this species is unknown, these results conform to the Charnov-Bull model of sex determination (in which female-to-male sex reversal can increase fitness to genetic females at higher temperatures), suggesting the system would reward further study. © 2018 Wiley Periodicals, Inc.

  14. Spatial patterns of the frog Oophaga pumilio in a plantation system are consistent with conspecific attraction.

    Science.gov (United States)

    Folt, Brian; Donnelly, Maureen A; Guyer, Craig

    2018-03-01

    The conspecific attraction hypothesis predicts that individuals are attracted to conspecifics because conspecifics may be cues to quality habitat and/or colonists may benefit from living in aggregations. Poison frogs (Dendrobatidae) are aposematic, territorial, and visually oriented-three characteristics which make dendrobatids an appropriate model to test for conspecific attraction. In this study, we tested this hypothesis using an extensive mark-recapture dataset of the strawberry poison frog ( Oophaga pumilio ) from La Selva Biological Station, Costa Rica. Data were collected from replicate populations in a relatively homogenous Theobroma cacao plantation, which provided a unique opportunity to test how conspecifics influence the spatial ecology of migrants in a controlled habitat with homogenous structure. We predicted that (1) individuals entering a population would aggregate with resident adults, (2) migrants would share sites with residents at a greater frequency than expected by chance, and (3) migrant home ranges would have shorter nearest-neighbor distances (NND) to residents than expected by chance. The results were consistent with these three predictions: Relative to random simulations, we observed significant aggregation, home-range overlap, and NND distribution functions in four, five, and six, respectively, of the six migrant-resident groups analyzed. Conspecific attraction may benefit migrant O. pumilio by providing cues to suitable home sites and/or increasing the potential for social interactions with conspecifics; if true, these benefits should outweigh the negative effects of other factors associated with aggregation. The observed aggregation between migrant and resident O. pumilio is consistent with conspecific attraction in dendrobatid frogs, and our study provides rare support from a field setting that conspecific attraction may be a relevant mechanism for models of anuran spatial ecology.

  15. Inferring ecological explanations for biogeographic boundaries of parapatric Asian mountain frogs.

    Science.gov (United States)

    Hu, Junhua; Jiang, Jianping

    2018-02-02

    Identifying and understanding the mechanisms that shape barriers to dispersal and resulting biogeographic boundaries has been a longstanding, yet challenging, goal in ecology, evolution and biogeography. Characterized by stable, adjacent ranges, without any intervening physical barriers, and limited, if any, range overlap in a narrow contact zone, parapatric species are an interesting system for studying biogeographic boundaries. The geographic ranges of two parapatric frog species, Feirana quadranus and F. taihangnica, meet in a contact zone within the Qinling Mountains, an important watershed for East Asia. To identify possible ecological determinants of the parapatric range boundaries for two closely related frog species, we quantified the extent of their niche differentiation in both geographical and environmental space combining ecological niche models with an ordination technique. We tested two alternative null hypotheses (sharp environmental gradients versus a ribbon of unsuitable habitat dividing two highly suitable regions) for biogeographic boundaries, against the null expectation that environmental variation across a given boundary is no greater than expected by chance. We found that the niches of these two parapatric species are more similar than expected by chance, but not equivalent. No sharp environmental gradient was found, while a ribbon of unsuitable habitat did act as a barrier for F. quadranus, but not for F. taihangnica. Integrating our findings with historical biogeographic information, our results suggest that at a contact zone, environmental tolerance restricted F. quadranus from dispersing further north, while interspecific competition most likely prevented the southward expansion of F. taihangnica. This study highlights the importance of both climate and competition in exploring ecological explanations for parapatric range boundaries between ecologically similar frog species, in particular under the effects of changing climate.

  16. Resting-state brain networks revealed by granger causal connectivity in frogs.

    Science.gov (United States)

    Xue, Fei; Fang, Guangzhan; Yue, Xizi; Zhao, Ermi; Brauth, Steven E; Tang, Yezhong

    2016-10-15

    Resting-state networks (RSNs) refer to the spontaneous brain activity generated under resting conditions, which maintain the dynamic connectivity of functional brain networks for automatic perception or higher order cognitive functions. Here, Granger causal connectivity analysis (GCCA) was used to explore brain RSNs in the music frog (Babina daunchina) during different behavioral activity phases. The results reveal that a causal network in the frog brain can be identified during the resting state which reflects both brain lateralization and sexual dimorphism. Specifically (1) ascending causal connections from the left mesencephalon to both sides of the telencephalon are significantly higher than those from the right mesencephalon, while the right telencephalon gives rise to the strongest efferent projections among all brain regions; (2) causal connections from the left mesencephalon in females are significantly higher than those in males and (3) these connections are similar during both the high and low behavioral activity phases in this species although almost all electroencephalograph (EEG) spectral bands showed higher power in the high activity phase for all nodes. The functional features of this network match important characteristics of auditory perception in this species. Thus we propose that this causal network maintains auditory perception during the resting state for unexpected auditory inputs as resting-state networks do in other species. These results are also consistent with the idea that females are more sensitive to auditory stimuli than males during the reproductive season. In addition, these results imply that even when not behaviorally active, the frogs remain vigilant for detecting external stimuli. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Deconstructing cartilage shape and size into contributions from embryogenesis, metamorphosis, and tadpole and frog growth.

    Science.gov (United States)

    Rose, Christopher S; Murawinski, Danny; Horne, Virginia

    2015-06-01

    Understanding skeletal diversification involves knowing not only how skeletal rudiments are shaped embryonically, but also how skeletal shape changes throughout life. The pharyngeal arch (PA) skeleton of metamorphosing amphibians persists largely as cartilage and undergoes two phases of development (embryogenesis and metamorphosis) and two phases of growth (larval and post-metamorphic). Though embryogenesis and metamorphosis produce species-specific features of PA cartilage shape, the extents to which shape and size change during growth and metamorphosis remain unaddressed. This study uses allometric equations and thin-plate spline, relative warp and elliptic Fourier analyses to describe shape and size trajectories for the ventral PA cartilages of the frog Xenopus laevis in tadpole and frog growth and metamorphosis. Cartilage sizes scale negatively with body size in both growth phases and cartilage shapes scale isometrically or close to it. This implies that most species-specific aspects of cartilage shape arise in embryogenesis and metamorphosis. Contributions from growth are limited to minor changes in lower jaw (LJ) curvature that produce relative gape narrowing and widening in tadpoles and frogs, respectively, and most cartilages becoming relatively thinner. Metamorphosis involves previously unreported decreases in cartilage size as well as changes in cartilage shape. The LJ becomes slightly longer, narrower and more curved, and the adult ceratohyal emerges from deep within the resorbing tadpole ceratohyal. This contrast in shape and size changes suggests a fundamental difference in the underlying cellular pathways. The observation that variation in PA cartilage shape decreases with tadpole growth supports the hypothesis that isometric growth is required for the metamorphic remodeling of PA cartilages. It also supports the existence of shape-regulating mechanisms that are specific to PA cartilages and that resist local adaptation and phenotypic plasticity.

  18. Skin microbiota in frogs from the Brazilian Atlantic Forest: Species, forest type, and potential against pathogens.

    Science.gov (United States)

    Assis, Ananda Brito de; Barreto, Cristine Chaves; Navas, Carlos Arturo

    2017-01-01

    The cutaneous microbiota of amphibians can be defined as a biological component of protection, since it can be composed of bacteria that produce antimicrobial compounds. Several factors influence skin microbial structure and it is possible that environmental variations are among one of these factors, perhaps through physical-chemical variations in the skin. This community, therefore, is likely modified in habitats in which some ecophysiological parameters are altered, as in fragmented forests. Our research goal was to compare the skin bacterial community of four anuran species of the Atlantic Forest of Brazil in landscapes from two different environments: continuous forest and fragmented forest. The guiding hypotheses were: 1) microbial communities of anuran skin vary among sympatric frog species of the Atlantic forest; 2) the degree to which forested areas are intact affects the cutaneous bacterial community of amphibians. If the external environment influences the skin microbiota, and if such influences affect microorganisms capable of inhibiting the colonization of pathogens, we expect consequences for the protection of host individuals. We compared bacterial communities based on richness and density of colony forming units; investigated the antimicrobial potential of isolated strains; and did the taxonomic identification of isolated morphotypes. We collected 188 individual frogs belonging to the species Proceratophrys boiei, Dendropsophus minutus, Aplastodiscus leucopygius and Phyllomedusa distincta, and isolated 221 bacterial morphotypes. Our results demonstrate variation in the skin microbiota of sympatric amphibians, but only one frog species exhibited differences in the bacterial communities between populations from fragmented and continuous forest. Therefore, the variation we observed is probably derived from both intrinsic aspects of the host amphibian species and extrinsic aspects of the environment occupied by the host. Finally, we detected

  19. Estimation of radiative parameters in participating media using shuffled frog leaping algorithm

    Directory of Open Access Journals (Sweden)

    Ren Ya-Tao

    2017-01-01

    Full Text Available The transient radiative transfer in 1-D homogeneous media with ultra-short Gaussian pulse laser irradiated was investigation by the finite volume method. The concept of optimal detection distance was proposed. The radiation characteristic was studied thoroughly. Afterwards, a memetic meta-heuristic shuffled frog leaping algorithm was introduced to inverse transient radiative problems. It is demonstrated that the extinction coefficient and scattering albedo can be retrieved accurately even with noisy data in a homogeneous absorbing and isotropic scattering plane-parallel slab. Finally, a technique was proposed to accelerate the inverse process by reducing the searching space of the radiative parameters.

  20. Cytoskeleton and Cytoskeleton-Bound RNA Visualization in Frog and Insect Oocytes.

    Science.gov (United States)

    Kloc, Malgorzata; Bilinski, Szczepan; Kubiak, Jacek Z

    2016-01-01

    The majority of oocyte functions involves and depends on the cytoskeletal elements, which include microtubules and actin and cytokeratin filaments. Various structures and molecules are temporarily or permanently bound to the cytoskeletal elements and their functions rely on cytoskeleton integrity and its timely assembly. Thus the accurate visualization of cytoskeleton is often crucial for studies and analyses of oocyte structure and functions. Here we describe several reliable methods for microtubule and/or microfilaments preservation and visualization in Xenopus oocyte extracts, and in situ in live and fixed insect and frog (Xenopus) oocytes. In addition, we describe visualization of cytoskeleton-bound RNAs using molecular beacons in live Xenopus oocytes.

  1. A syncopated leap-frog algorithm for orbit consistent plasma simulation of materials processing reactors

    International Nuclear Information System (INIS)

    Cobb, J.W.; Leboeuf, J.N.

    1994-01-01

    The authors present a particle algorithm to extend simulation capabilities for plasma based materials processing reactors. The orbit integrator uses a syncopated leap-frog algorithm in cylindrical coordinates, which maintains second order accuracy, and minimizes computational complexity. Plasma source terms are accumulated orbit consistently directly in the frequency and azimuthal mode domains. Finally they discuss the numerical analysis of this algorithm. Orbit consistency greatly reduces the computational cost for a given level of precision. The computational cost is independent of the degree of time scale separation

  2. Complex spatial dynamics maintain northern leopard frog (Lithobates pipiens) genetic diversity in a temporally varying landscape

    Science.gov (United States)

    Mushet, David M.; Euliss, Ned H.; Chen, Yongjiu; Stockwell, Craig A.

    2013-01-01

    In contrast to most local amphibian populations, northeastern populations of the Northern Leopard Frog (Lithobates pipiens) have displayed uncharacteristically high levels of genetic diversity that have been attributed to large, stable populations. However, this widely distributed species also occurs in areas known for great climatic fluctuations that should be reflected in corresponding fluctuations in population sizes and reduced genetic diversity. To test our hypothesis that Northern Leopard Frog genetic diversity would be reduced in areas subjected to significant climate variability, we examined the genetic diversity of L. pipiens collected from 12 sites within the Prairie Pothole Region of North Dakota. Despite the region's fluctuating climate that includes periods of recurring drought and deluge, we found unexpectedly high levels of genetic diversity approaching that of northeastern populations. Further, genetic structure at a landscape scale was strikingly homogeneous; genetic differentiation estimates (Dest) averaged 0.10 (SD = 0.036) across the six microsatellite loci we studied, and two Bayesian assignment tests (STRUCTURE and BAPS) failed to reveal the development of significant population structure across the 68 km breadth of our study area. These results suggest that L. pipiens in the Prairie Pothole Region consists of a large, panmictic population capable of maintaining high genetic diversity in the face of marked climate variability.

  3. Vocal responses of austral forest frogs to amplitude and degradation patterns of advertisement calls.

    Science.gov (United States)

    Penna, Mario; Moreno-Gómez, Felipe N; Muñoz, Matías I; Cisternas, Javiera

    2017-07-01

    Degradation phenomena affecting animal acoustic signals may provide cues to assess the distance of emitters. Recognition of degraded signals has been extensively demonstrated in birds, and recently studies have also reported detection of degraded patterns in anurans that call at or above ground level. In the current study we explore the vocal responses of the syntopic burrowing male frogs Eupsophus emiliopugini and E. calcaratus from the South American temperate forest to synthetic conspecific calls differing in amplitude and emulating degraded and non-degraded signal patterns. The results show a strong dependence of vocal responses on signal amplitude, and a general lack of differential responses to signals with different pulse amplitude modulation depths in E. emiliopugini and no effect of relative amplitude of harmonics in E. calcaratus. Such limited discrimination of signal degradation patterns from non-degraded signals is likely related to the burrowing habits of these species. Shelters amplify outgoing and incoming conspecific vocalizations, but do not counteract signal degradation to an extent comparable to calling strategies used by other frogs. The limited detection abilities and resultant response permissiveness to degraded calls in these syntopic burrowing species would be advantageous for animals communicating in circumstances in which signal alteration prevails. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Responses of male cricket frogs (Acris crepitans) to attenuated and degraded advertisement calls.

    Science.gov (United States)

    Venator, Kurt R; Ryan, Michael J; Wilczynski, Walter

    2017-05-01

    We examined the vocal and non-vocal responses of male cricket frogs ( Acris crepitans ) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (AM). Both are characteristic of changes to the call as it is transmitted through natural habitats. As stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indicative of increased aggressive interactions. At the higher intensities and lower degradation levels, the probability that males would shift to one of two non-vocal behavioral responses, attacking the perceived intruder or ceasing calling and abandoning the call site, gradually increased. The results show that differences in signal attenuation and AM degradation levels are perceived by males and trigger both vocal and non-vocal behavioral responses consistent with their use in evaluating the distance to a challenging male. Furthermore, the results indicate that the male responses are graded, increasing as intensity rises and degradation falls, and hierarchical, with vocal responses preceding behavioral responses over the range of intensities and degradation levels presented.

  5. Interspecific variation in the phenology of advertisement calling in a temperate Australian frog community.

    Science.gov (United States)

    Heard, Geoffrey W; Canessa, Stefano; Parris, Kirsten M

    2015-09-01

    Spatial and temporal partitioning of resources underlies the coexistence of species with similar niches. In communities of frogs and toads, the phenology of advertisement calling provides insights into temporal partitioning of reproductive effort and its implications for community dynamics. This study assessed the phenology of advertisement calling in an anuran community from Melbourne, in southern Australia. We collated data from 1432 surveys of 253 sites and used logistic regression to quantify seasonality in the nightly probability of calling and the influence of meteorological variables on this probability for six species of frogs. We found limited overlap in the predicted seasonal peaks of calling among these species. Those shown to have overlapping calling peaks are unlikely to be in direct competition, due to differences in larval ecology (Crinia signifera and Litoria ewingii) or differences in calling behavior and acoustics (Limnodynastes dumerilii and Litoria raniformis). In contrast, closely related and ecologically similar species (Crinia signfera and Crinia parinsignifera;Litoria ewingii and Litoria verreauxii) appear to have staggered seasonal peaks of calling. In combination with interspecific variation in the meteorological correlates of calling, these results may be indicative of temporal partitioning of reproductive activity to facilitate coexistence, as has been reported for tropical and temperate anurans from other parts of the globe.

  6. Relationships between leukocytes and Hepatozoon spp. In green frogs, Rana clamitans.

    Science.gov (United States)

    Shutler, Dave; Smith, Todd G; Robinson, Stephen R

    2009-01-01

    There are few published data on amphibian leukocyte profiles, and relationships between amphibian leukocytes and parasites are even less well known. Using counts from 35 pairs of blood smears taken 2 days apart, we tested for correlations between leukocyte proportions and infection intensities of Hepatozoon spp. (either Hepatozoon catesbianae or Hepatozoon clamatae) in green frogs (Rana clamitans). On average (SE), we counted 65.4 (1.7) lymphocytes, 14.0 (1.3) neutrophils, 19.3 (1.6) eosinophils, 0.9 (0.1) monocytes, and 0.4 (0.1) basophils per 100 leukocytes. All frogs harbored Hepatozoon spp. (median seven parasites per 100 leukocytes; range 1-250). Significant relationships were not observed between numbers of leukocytes and infection intensities of Hepatozoon spp. Among the possible explanations for these null results are that Hepatozoon spp. is benign, that Hepatozoon spp. is able to evade detection by the immune system, that Hepatozoon spp. is able to manipulate leukocyte investment, or that other unmeasured or undetected parasites were more important in affecting immune response.

  7. Modeling habitat connectivity to inform reintroductions: a case study with the Chiricahua Leopard Frog

    Science.gov (United States)

    Jarchow, Christopher J.; Hossack, Blake R.; Sigafus, Brent H.; Schwalbe, Cecil R.; Muths, Erin L.

    2016-01-01

    Managing species with intensive tools such as reintroduction may focus on single sites or entire landscapes. For vagile species, long-term persistence will require colonization and establishment in neighboring habitats. Therefore, both suitable colonization sites and suitable dispersal corridors between sites are required. Assessment of landscapes for both requirements can contribute to ranking and selection of reintroduction areas, thereby improving management success. Following eradication of invasive American Bullfrogs (Lithobates catesbeianus) from most of Buenos Aires National Wildlife Refuge (BANWR; Arizona, United States), larval Chiricahua Leopard Frogs (Lithobates chiricahuensis) from a private pond were reintroduced into three stock ponds. Populations became established at all three reintroduction sites followed by colonization of neighboring ponds in subsequent years. Our aim was to better understand colonization patterns by the federally threatened L. chiricahuensis which could help inform other reintroduction efforts. We assessed the influence of four landscape features on colonization. Using surveys from 2007 and information about the landscape, we developed a habitat connectivity model, based on electrical circuit theory, that identified potential dispersal corridors after explicitly accounting for imperfect detection of frogs. Landscape features provided little insight into why some sites were colonized and others were not, results that are likely because of the uniformity of the BANWR landscape. While corridor modeling may be effective in more-complex landscapes, our results suggest focusing on local habitat will be more useful at BANWR. We also illustrate that existing data, even when limited in spatial or temporal resolution, can provide information useful in formulating management actions.

  8. Reel Royal Diversity? The Glass Ceiling in Disney’s Mulan and Princess and the Frog

    Directory of Open Access Journals (Sweden)

    Lauren Dundes

    2016-12-01

    Full Text Available Both in Mulan and Princess and the Frog, Disney eschews a traditional fairytale ending involving palatial opulence by substituting an alternative narrative for women of color. Mulan disguises herself as a male soldier in order to serve in her father’s place. After sharing victory with male companions, she willingly returns home to domesticity and the confines imposed by her gender. Tiana spends two thirds of the movie as a frog, substantially limiting her on-screen time as an African American female. Like Mulan, she is driven to please her father. She fulfills his dream of owning a high-end restaurant, ironically named Tiana’s Palace, the closest she comes to a royal lifestyle. Although protagonists with more realistic lives could potentially enhance viewers’ connection with them and model a work ethic or commitment to home life, the standard and more financially successful Disney narrative immerses viewers in a fantasy world of endless prospects including a life of royalty. These nonwhite heroines instead display a willingness to settle for more modest aspirations in stories replete with stereotypical gender and race-bound tropes. This divergent narrative suggests that protagonists of color are not entitled to a life of leisure and privilege that white Disney princesses enjoy.

  9. Effects of the herbicides linuron and S-metolachlor on Perez's frog embryos.

    Science.gov (United States)

    Quintaneiro, Carla; Soares, Amadeu M V M; Monteiro, Marta S

    2018-03-01

    Presence of pesticides in the environment and their possible effects on aquatic organisms are of great concern worldwide. The extensive use of herbicides in agricultural areas are one of the factors contributing to the known decline of amphibian populations. Thus, as non-target species, amphibians can be exposed in early life stages to herbicides in aquatic systems. In this context, this study aims to evaluate effects of increasing concentrations of two maize herbicides, linuron and S-metolachlor on embryos of the Perez' frog (Pelophylax perezi) during 192 h. Apical endpoints were determined for each herbicide: mortality, hatching rate, malformations and length. Frog embryos presented a LC 50 of 21 mg/l linuron and 37.5 mg/l S-metolachlor. Furthermore, sub-lethal concentrations of both herbicides affected normal embryonic development, delaying hatching, decreasing larvae length and causing several malformations. Length of larvae decreased with increasing concentrations of each herbicide, even at the lower concentrations tested. Malformations observed in larvae exposed to both herbicides were oedemas, spinal curvature and deformation, blistering and microphtalmia. Overall, these results highlight the need to assess adverse effects of xenobiotics to early life stages of amphibians regarding beside mortality the embryonic development, which could result in impairments at later stages. However, to unravel mechanisms involved in toxicity of these herbicides further studies regarding lower levels of biological organisation such as biochemical and genomic level should be performed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Nonlinear Rayleigh wave inversion based on the shuffled frog-leaping algorithm

    Science.gov (United States)

    Sun, Cheng-Yu; Wang, Yan-Yan; Wu, Dun-Shi; Qin, Xiao-Jun

    2017-12-01

    At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear global optimization problem. In order to alleviate the risk of falling into a local optimal solution, this paper introduces a new global optimization method, the shuffle frog-leaping algorithm (SFLA), into the Rayleigh wave dispersion-curve inversion process. SFLA is a swarm-intelligence-based algorithm that simulates a group of frogs searching for food. It uses a few parameters, achieves rapid convergence, and is capability of effective global searching. In order to test the reliability and calculation performance of SFLA, noise-free and noisy synthetic datasets were inverted. We conducted a comparative analysis with other established algorithms using the noise-free dataset, and then tested the ability of SFLA to cope with data noise. Finally, we inverted a real-world example to examine the applicability of SFLA. Results from both synthetic and field data demonstrated the effectiveness of SFLA in the interpretation of Rayleigh wave dispersion curves. We found that SFLA is superior to the established methods in terms of both reliability and computational efficiency, so it offers great potential to improve our ability to solve geophysical inversion problems.

  11. A simplified table for staging embryos of the pipid frog Pipa arrabali

    Directory of Open Access Journals (Sweden)

    OLÍVIA G.S. ARAÚJO

    Full Text Available ABSTRACT Pipa is a Neotropical genus of frogs that dwell in freshwater environments. It includes four species that lack free-swimming larvae (P. aspera, P. arrabali, P. pipa, and P. snethlageae and three with tadpoles (P. carvalhoi, P. myersi, and P. parva. Developmental tables such as the one proposed by Nieuwkoop and Faber might be useful for Pipa species with tadpoles. However, for the other Pipa species, to determine stages by this table or by any of the tables already prepared for frogs without tadpoles (e.g., Crinia nimbus, Eleutherodactylus coqui, and Oreobates barituensis is impossible. By using embryonic, juvenile, and subadult specimens, we generated a staging table for P. arrabali, from the moment limb buds were first observed until birth, based on diagnostic features such as snout-vent length; growth, morphology, and reabsorption of the external tail; growth and differentiation of fore and hind limbs; development of intestine and vent tube; position of the angle of the mouth relative to nostrils and eyes; and color of preserved individuals. Based on these observations, we discuss some noteworthy traits (e.g., posture of hands and feet. We also compare the pattern of development of P. arrabali with that of other anuran species (with and without tadpoles.

  12. DDT exposure of frogs: A case study from Limpopo Province, South Africa.

    Science.gov (United States)

    Viljoen, Ignatius M; Bornman, Riana; Bouwman, Hindrik

    2016-09-01

    Amphibians are globally under pressure with environmental contaminants contributing to this. Despite caution aired more than 80 years ago of threats posed to amphibians by DDT spraying for disease vector control, no data have been published on concentrations or effects of DDT contamination in frogs from areas where DDT is actively sprayed to control the insect vectors of malaria. In this study, we sampled fat bodies of Xenopus laevis and Xenopus muelleri naturally occurring in an area where indoor residual spraying of DDT is employed and from adjacent, non-sprayed, areas. ΣDDT concentrations ranged between DDT in the eggs of the Grey Heron Ardea cinerea. This suggests that the DDT we found in frogs may have contributed to DDT loadings higher in the food web. These findings, combined with other studies from this area, support the need to reduce and eventually move away from DDT in malaria control safely and sustainably. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Exceptional soft tissues preservation in a mummified frog-eating Eocene salamander

    Directory of Open Access Journals (Sweden)

    Jérémy Tissier

    2017-10-01

    Full Text Available Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was ‘mummified’ (likely between 40 and 34 million years ago in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei, whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

  14. Taurine biosynthesis in frog retina: effects of light and dark adaptations

    International Nuclear Information System (INIS)

    Nishimura, C.; Ida, S.; Kuriyama, K.

    1983-01-01

    The retinal uptake and metabolism of cysteine, a precursor for taurine biosynthesis, were analysed using the bull frog. The [ 14 C] cysteine uptake into isolated retina had some specific properties: It was rather temperature independent, required Na ions, was inhibited by ouabain but not by dinitrophenol, and exhibited saturation kinetics composed of two components. When retinal homogenate was incubated with 12-30 microM of L-[U- 14 C]cysteine, the accumulation of labeled alanine, cysteine sulfinic acid (CSA), cysteic acid (CA), hypotaurine, and taurine was detected. The metabolic conversions of [ 14 C] cysteine to labeled alanine, hypotaurine, and taurine were linear over 90 minutes. Prolonged light adaptation (3 weeks) induced a significant reduction in the formation of labeled CA, CSA, hypotaurine, and taurine from [ 14 C] cysteine. On the other hand, it was found that in dark-adapted retinae, the formation of labeled taurine from [ 14 C] cysteine increased significantly in spite of the reduction in the formation of labeled CA. These results indicate that biosynthetic pathways exist for taurine from cysteine in frog retina, and that these metabolic pathways are involved in the regulation of retinal taurine content under continuous visual adaptation

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

    Science.gov (United States)

    Menezes, Riya C.; Jayarajan, Aditi; Shanker, Kartik

    2016-01-01

    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

  16. Microhabitat and Climatic Niche Change Explain Patterns of Diversification among Frog Families.

    Science.gov (United States)

    Moen, Daniel S; Wiens, John J

    2017-07-01

    A major goal of ecology and evolutionary biology is to explain patterns of species richness among clades. Differences in rates of net diversification (speciation minus extinction over time) may often explain these patterns, but the factors that drive variation in diversification rates remain uncertain. Three important candidates are climatic niche position (e.g., whether clades are primarily temperate or tropical), rates of climatic niche change among species within clades, and microhabitat (e.g., aquatic, terrestrial, arboreal). The first two factors have been tested separately in several studies, but the relative importance of all three is largely unknown. Here we explore the correlates of diversification among families of frogs, which collectively represent ∼88% of amphibian species. We assemble and analyze data on phylogeny, climate, and microhabitat for thousands of species. We find that the best-fitting phylogenetic multiple regression model includes all three types of variables: microhabitat, rates of climatic niche change, and climatic niche position. This model explains 67% of the variation in diversification rates among frog families, with arboreal microhabitat explaining ∼31%, niche rates ∼25%, and climatic niche position ∼11%. Surprisingly, we show that microhabitat can have a much stronger influence on diversification than climatic niche position or rates of climatic niche change.

  17. Morphology, ecology, and behaviour of Hylarana intermedia, a Western Ghats frog

    Directory of Open Access Journals (Sweden)

    Ambika Kamath

    2016-06-01

    Full Text Available Despite being common in the Western Ghats-Sri Lanka biodiversity hotspot, Golden-backed frogs (Hylarana, Ranidae remain poorly studied. In this paper, we present some preliminary data on the morphology, behaviour, and habitat use of Hylarana intermedia, a member of the Hylarana aurantiaca species group. We find evidence for female biased size dimorphism, as well as potential shape differences between the sexes in this species. Additionally, we investigate the relationships between traits that may contribute to male conspicuousness (call rates, dorsal coloration, and body size in two breeding habitats, a paddy field and a trench. Our results suggest both size-dependent and environment-dependent variation in call rate and colour in this species. Specifically, we find evidence against the adoption of sneaker mating strategies by small males in H. intermedia, and instead find variation both within and between populations in traits contributing to male conspicuousness. We conclude by proposing future directions for research on this common frog species.

  18. The unexpectedly dull tadpole of Madagascar’s largest frog, Mantidactylus guttulatus

    Directory of Open Access Journals (Sweden)

    Arne Schulze

    2016-12-01

    Full Text Available The Madagascar-endemic mantellid genus Mantidactylus contains one subclade with two described frog species characterized by very large body sizes. This subclade is classified as the subgenus Mantidactylus and is widespread in eastern and northern Madagascar, but their reproductive biology and larval stages are still unknown. We here provide a detailed description of the larvae of one species in this subgenus, M. guttulatus, on the basis of genetic assignment (16S DNA barcoding. The tadpoles were collected in the dry season from shallow waters near a stream in the Mahajanga Province in northwestern Madagascar. Their body and tail shape is remarkably generalized as typical for stream-adapted tadpoles, and the oral disc and labial keratodont row formula (4(2-4/3(1 are similar to those of other lotic mantellid frog larvae with generalized mouthparts like those in the subgenus Brygoomantis. The well-separated positions of these subgenera in the mantellid phylogeny suggest extensive homoplasy in the evolution of larval mouthpart morphology within Mantidactylus.

  19. Foam nests provide context-dependent thermal insulation to embryos of three leptodactylid frogs.

    Science.gov (United States)

    Méndez-Narváez, J; Flechas, S V; Amézquita, A

    2015-01-01

    The choice of adequate breeding habitat and its associated thermoregulatory conditions are thought to be important in the evolution of amphibian reproductive strategies. Among leptodactylid frogs, there is a terrestrial cline in the oviposition sites chosen to build foam nests for eggs. Although several functions have been attributed to foam nests, their role in temperature regulation for embryos is unclear. Here we tested the hypothesis that foam nests buffer embryos from variation in air temperature. We examined the degree of terrestrial nest sites in three species, finding a terrestrial cline of sites in terms of distance from water. We tested whether this nest-insulation effect varied among these species that differ in the degree of terrestrial nest sites and whether translocating nests impacted embryonic mortality. Our results demonstrate a negative effect of translocating aquatic nests to land, inferred from the highest hatching success in natural nests sites. All nests attenuated environmental thermal variation, but more terrestrial nests buffered embryos from a greater range of temperatures than did aquatic ones. Altogether, our data indicate that foam nests insulate embryos from daily temperature fluctuations among leptodactylid frogs with different degrees of terrestrial nests, which may well have contributed to the evolution of this reproductive strategy.

  20. Hemoparasites in Oregon spotted frogs (Rana pretiosa) from central Oregon, USA.

    Science.gov (United States)

    Stenberg, Patricia L; Bowerman, William J

    2008-04-01

    Between 2001 and 2003, we screened blood smears of 156 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon for blood parasites. A Lankesterella sp. and a Trypanosoma sp. were detected in 31% and 35% of the frogs, respectively. Parasite loads were generally light, with Lankesterella sporozoites in 1-2% of erythrocytes, and extracellular trypanosomes were seen at rates of about one parasite per 200 fields of view at 1,000x. Little work has been published on hemoparasites of ranids in the western USA in the past 30 yr. Because of the recent taxonomic division of the Rana pretiosa complex, this may be the first published report of blood parasites for R. pretiosa sensu stricto. Both parasites reported here differed in morphologic features and morphometric comparisons from previous descriptions of anuran hemoparasites. Much work remains to sort out the taxonomy of hemoparasites among western USA ranids and to determine the ecological significance of these parasites; both tasks are important steps in understanding and managing these, and related, sensitive and threatened species.

  1. An improved shuffled frog leaping algorithm based evolutionary framework for currency exchange rate prediction

    Science.gov (United States)

    Dash, Rajashree

    2017-11-01

    Forecasting purchasing power of one currency with respect to another currency is always an interesting topic in the field of financial time series prediction. Despite the existence of several traditional and computational models for currency exchange rate forecasting, there is always a need for developing simpler and more efficient model, which will produce better prediction capability. In this paper, an evolutionary framework is proposed by using an improved shuffled frog leaping (ISFL) algorithm with a computationally efficient functional link artificial neural network (CEFLANN) for prediction of currency exchange rate. The model is validated by observing the monthly prediction measures obtained for three currency exchange data sets such as USD/CAD, USD/CHF, and USD/JPY accumulated within same period of time. The model performance is also compared with two other evolutionary learning techniques such as Shuffled frog leaping algorithm and Particle Swarm optimization algorithm. Practical analysis of results suggest that, the proposed model developed using the ISFL algorithm with CEFLANN network is a promising predictor model for currency exchange rate prediction compared to other models included in the study.

  2. Equivalent circuit of frog atrial tissue as determined by voltage clamp-unclamp experiments.

    Science.gov (United States)

    Tarr, M; Trank, J

    1971-11-01

    The equivalent circuit that has been used in the analysis of nerve voltage-clamp data is that of the membrane capacity in parallel with the membrane resistance. Voltage-clamp experiments on frog atrial tissue indicate that this circuit will not suffice for this cardiac tissue. The change in membrane current associated with a step change in membrane potential does not show a rapid spike of capacitive current as would be expected for the simple parallel resistance-capacitance network. Rather, there is a step change in current followed by an exponential decay in current with a time constant of about 1 msec. This relatively slow capacitive charging current suggests that there is a resistance in series with the membrane capacity. A possible equivalent circuit is that of a series resistance external to the parallel resistance-capacitance network of the cell membranes. Another possible circuit assumes that the series resistance is an integral part of the cell membrane. The data presented in this paper demonstrate that the equivalent circuit of a bundle of frog atrial muscle is that of an external resistance in series with the cell membranes.

  3. Seasonal Variation in the Hepatoproteome of the Dehydration- and Freeze-Tolerant Wood Frog, Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Jon P. Costanzo

    2011-11-01

    Full Text Available Winter’s advent invokes physiological adjustments that permit temperate ectotherms to cope with stresses such as food shortage, water deprivation, hypoxia, and hypothermia. We used liquid chromatography (LC in combination with tandem mass spectrometry (MS/MS quantitative isobaric (iTRAQ™ peptide mapping to assess variation in the abundance of hepatic proteins in summer- and winter-acclimatized wood frogs (Rana sylvatica, a northerly-distributed species that tolerates extreme dehydration and tissue freezing during hibernation. Thirty-three unique proteins exhibited strong seasonal lability. Livers of winter frogs had relatively high levels of proteins involved in cytoprotection, including heat-shock proteins and an antioxidant, and a reduced abundance of proteins involved in cell proliferation, protein synthesis, and mitochondrial function. They also exhibited altered levels of certain metabolic enzymes that participate in the biochemical reorganization associated with aphagia and reliance on energy reserves, as well as the freezing mobilization and post-thaw recovery of glucose, an important cryoprotective solute in freezing adaptation.

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

    Directory of Open Access Journals (Sweden)

    Gayani Senevirathne

    Full Text Available 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.

  5. Ranid Herpesvirus 3 and Proliferative Dermatitis in Free-Ranging Wild Common Frogs (Rana Temporaria).

    Science.gov (United States)

    Origgi, F C; Schmidt, B R; Lohmann, P; Otten, P; Akdesir, E; Gaschen, V; Aguilar-Bultet, L; Wahli, T; Sattler, U; Stoffel, M H

    2017-07-01

    Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.

  6. Design of an Electric Commutated Frog-Leg Winding Permanent-Magnet DC Machine

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    2014-03-01

    Full Text Available An electric commutated frog-leg winding permanent-magnet (PM DC machine is proposed in this paper. It has a semi-closed slotted stator with a classical type of mesh winding introduced from the conventional brushed DC machine and a polyphase electric commutation besides a PM excitation rotor and a circular arrayed Hall position sensor. Under the cooperation between the position sensor and the electric commutation, the proposed machine is basically operated on the same principle of the brushed one. Because of its simplex frog-leg winding, the combination between poles and slots is designed as 4/22, and the number of phases is set as 11. By applying an exact analytical method, which is verified comparable with the finite element analyses (FEA, to the prediction of its instantaneous magnetic field, electromotive force (EMF, cogging torque and output torque, it is well designed with a series of parameters in dimension aiming at the lowest cogging torque. A 230 W, 4-pole, and 22-slot new machine is prototyped and tested to verify the analysis.

  7. A New Species of Frog (Anura: Dicroglossidae) Discovered from the Mega City of Dhaka.

    Science.gov (United States)

    Howlader, Mohammad Sajid Ali; Nair, Abhilash; Merilä, Juha

    2016-01-01

    We describe a new species of frog of the genus Zakerana discovered from the urban core of Dhaka, Bangladesh, one of the most densely populated cities in the world. Although the new species is morphologically similar to the geographically proximate congeners in the Bangladeshi cricket frog group, we show that it can be distinguished from all congeners on the basis of morphological characters, advertisement calls and variation in two mitochondrial DNA genes (12S rRNA and 16S rRNA). Apart from several diagnostic differences in body proportions, the new species differs from other Zakerana species in having a flattened snout (from ventral view) projecting over the lower jaw, and diagnostic trapezoid-shaped red markings on the vocal sac in males. Molecular genetic analyses show that the new species is highly divergent (3.1-20.1% sequence divergence) from all congeneric species, and forms a well-supported clade with its sister species, Zakerana asmati. The discovery of a new amphibian species from the urban core of Dhaka together with several recent descriptions of new amphibian species from Bangladesh may indicate that more amphibian species remain to be discovered from this country.

  8. The electrical properties of auditory hair cells in the frog amphibian papilla.

    Science.gov (United States)

    Smotherman, M S; Narins, P M

    1999-07-01

    The amphibian papilla (AP) is the principal auditory organ of the frog. Anatomical and neurophysiological evidence suggests that this hearing organ utilizes both mechanical and electrical (hair cell-based) frequency tuning mechanisms, yet relatively little is known about the electrophysiology of AP hair cells. Using the whole-cell patch-clamp technique, we have investigated the electrical properties and ionic currents of isolated hair cells along the rostrocaudal axis of the AP. Electrical resonances were observed in the voltage response of hair cells harvested from the rostral and medial, but not caudal, regions of the AP. Two ionic currents, ICa and IK(Ca), were observed in every hair cell; however, their amplitudes varied substantially along the epithelium. Only rostral hair cells exhibited an inactivating potassium current (IA), whereas an inwardly rectifying potassium current (IK1) was identified only in caudal AP hair cells. Electrically tuned hair cells exhibited resonant frequencies from 50 to 375 Hz, which correlated well with hair cell position and the tonotopic organization of the papilla. Variations in the kinetics of the outward current contribute substantially to the determination of resonant frequency. ICa and IK(Ca) amplitudes increased with resonant frequency, reducing the membrane time constant with increasing resonant frequency. We conclude that a tonotopically organized hair cell substrate exists to support electrical tuning in the rostromedial region of the frog amphibian papilla and that the cellular mechanisms for frequency determination are very similar to those reported for another electrically tuned auditory organ, the turtle basilar papilla.

  9. Declines revisited: Long-term recovery and spatial population dynamics oftailed frog larvae after wildfire

    Science.gov (United States)

    Hossack, Blake R.; Honeycutt, Richard

    2017-01-01

    Drought has fueled an increased frequency and severity of large wildfires in many ecosystems. Despite an increase in research on wildfire effects on vertebrates, the vast majority of it has focused on short-term (effects and there is still little information on the time scale of population recovery for species that decline in abundance after fire. In 2003, a large wildfire in Montana (USA) burned the watersheds of four of eight streams that we sampled for larval Rocky Mountain tailed frogs (Ascaphus montanus) in 2001. Surveys during 2004–2005 revealed reduced abundance of larvae in burned streams relative to unburned streams, with greater declines associated with increased fire extent. Rocky Mountain tailed frogs have low vagility and have several unusual life-history traits that could slow population recovery, including an extended larval period (4 years), delayed sexual maturity (6–8 years), and low fecundity (negative effects of burn extent on larval abundance weakened> 58% within 12 years after the fire. We also found moderate synchrony among populations in unburned streams and negative spatial autocorrelation among populations in burned streams. We suspect negative spatial autocorrelation among spatially-clustered burned streams reflected increased post-fire patchiness in resources and different rates of local recovery. Our results add to a growing body of work that suggests populations in intact ecosystems tend to be resilient to habitat changes caused by wildfire. Our results also provide important insights into recovery times of populations that have been negatively affected by severe wildfire.

  10. Exceptional soft tissues preservation in a mummified frog-eating Eocene salamander.

    Science.gov (United States)

    Tissier, Jérémy; Rage, Jean-Claude; Laurin, Michel

    2017-01-01

    Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was 'mummified' (likely between 40 and 34 million years ago) in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei , whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

  11. Acute toxicity of Headline® fungicide to Blanchard's cricket frogs (Acris blanchardi).

    Science.gov (United States)

    Cusaac, J Patrick W; Morrison, Shane A; Belden, Jason B; Smith, Loren M; McMurry, Scott T

    2016-04-01

    Previous laboratory studies have suggested that pyraclostrobin-containing fungicide formulations are toxic to amphibians at environmentally relevant concentrations. However, it is unknown if all pyraclostrobin formulations have similar toxicity and if toxicity occurs in different amphibian species. We investigated the acute toxicity of two formulations, Headline(®) fungicide and Headline AMP(®) fungicide, to Blanchard's cricket frogs (Acris blanchardi) based on a direct overspray scenario. In addition, we examined body residues of fungicide active ingredients in A. blanchardi following direct exposure to Headline AMP fungicide. Headline fungicide and Headline AMP fungicide had similar toxicity to A. blanchardi with calculated median lethal doses of 2.1 and 1.7 µg pyraclostrobin/cm(2), respectively, which are similar to the suggested maximum label rate in North American corn (2.2 and 1.52 µg pyraclostrobin/cm(2), respectively). Tissue concentrations of pyraclostrobin were lower than predicted based on full uptake of a direct dose, and did not drop during the first 24 h after exposure. Headline fungicides at corn application rates are acutely toxic to cricket frogs, but acute toxicity in the field will depend on worst-case exposure.

  12. Accelerated hatching of southern leopard frog (Rana sphenocephala) eggs in response to the presence of a crayfish Procambarus nigrocinctus predator

    Science.gov (United States)

    Daniel Saenz; James B. Johnson; Cory K. Adams; Gage H. Dayton

    2003-01-01

    Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala)...

  13. Amazon poison frogs (Ranitomeya amazonica) use different phytotelm characteristics to determine their suitablility for egg and tadpole deposition

    NARCIS (Netherlands)

    Poelman, E.H.; Wijngaarden, van R.P.A.; Raaijmakers, C.E.

    2013-01-01

    Parents have to assess the multivariate characteristics of their reproductive sites to maximize their reproductive success through offspring performance. In addition, they may provide care to ensure optimal performance of their offspring. In poison frogs it has been identified that ecological

  14. Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae)

    NARCIS (Netherlands)

    Born, M.; Bongers, F.; Poelman, E.H.; Sterck, F.J.

    2010-01-01

    Dry-season retreat and dietary shift of the dart-poison frog Delldrobates tillCtOrillS (Anura: Dendrobatidae). Seasonal rainfall affects tropical forest dynamics and behavior of species that are part of these ecosystems. TIle positive correlation between amphibian ac tivity pattems and rainfall has

  15. An increase in [Ca2+]i activates basolateral chloride channels and inhibits apical sodium channels in frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Rytved, K A; Nielsen, R

    1996-01-01

    The aim of this study was to investigate the mechanisms by which increases in free cytosolic calcium ([Ca2+]i) cause a decrease in macroscopic sodium absorption across principal cells of the frog skin epithelium. [Ca2+]i was measured with fura-2 in an epifluorescence microscope set-up, sodium abs...

  16. 76 FR 55413 - Proposed Safe Harbor Agreement for California Red-legged Frog, California Tiger Salamander, Smith...

    Science.gov (United States)

    2011-09-07

    ...] Proposed Safe Harbor Agreement for California Red-legged Frog, California Tiger Salamander, Smith's Blue... endangered Smith's blue butterfly (Euphilotes enoptes smithi) under the Endangered Species Act of 1973, as..., California tiger salamander, Smith's blue butterfly, and Yadon's piperia on the property subject to the...

  17. Water velocity tolerance in tadpoles of the foothill yellow-legged frog (Rana boylii): Swimming performance, growth, and survival

    Science.gov (United States)

    S. Kupferberg; A. Lind; V. Thill; S. Yarnell

    2011-01-01

    We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog, Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit...

  18. Molecular phylogeny, morphology and bioacoustics reveal five additional species of arboreal microhylid frogs of the genus Anodonthyla from Madagascar

    NARCIS (Netherlands)

    Vences, M.; Glaw, F.; Köhler, J.; Wollenberg, K.C.

    2010-01-01

    We provide a partial revision of the microhylid frogs of the genus Anodonthyla, endemic to Madagascar, based on comprehensive molecular, bioacoustic and morphological data sets that include newly collected specimens from multiple localities. The molecular trees provide strong evidence for the

  19. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Science.gov (United States)

    2011-07-29

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R8-ES-2011-N144; 81440-1113-0000-F3] Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis Obispo... Ranch in San Luis Obispo County, California. Within the 620 acres of land comprising the Enrolled...

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

    Science.gov (United States)

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

  1. Effects of Endocrine Disruptors Ethinylestradiol and Procloraz on the vocal system of the frog Xenopus tropicalis

    DEFF Research Database (Denmark)

    Brande-Lavridsen, Nanna; Nørum, Ulrik; Korsgaard, Bodil

    2009-01-01

    -male competitive interactions. The call is associated with larger more numerous neural and muscular structures of sound production. The vocalization system of Xenopus and other Pipid frogs, the larynx and associated structures, is extremely sexual dimorphic. This includes both gross morphology such as size...

  2. Airborne Pesticides as an Unlikely Cause for Population Declines of Alpine Frogs in the Sierra Nevada, California

    Science.gov (United States)

    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...

  3. Terrestrial movements and habitat use of gopher frogs in longleaf pine forests: a comparative study of juveniles and adults

    Science.gov (United States)

    Elizabeth A. Roznik; Steve A. Johnson; Cathryn H. Greenberg; George W. Tanner

    2009-01-01

    Many animals exhibit changes in patterns of movement and habitat use as they age, and understanding such ontogenetic shifts is important for ensuring that habitat management is appropriate for all life stages. We used radiotelemetry to study movements and habitat use of juvenile and adult gopher frogs (Rana capito) as they migrated from the same ponds following...

  4. Four new species of frogs and one new species of snake from the Chapare region of Bolivia, with notes on other species

    Science.gov (United States)

    Reynolds, R.P.; Foster, M.S.

    1992-01-01

    We report on a collection of 74 frogs, 11 lots of frog eggs or tadpoles, and two snakes collected from the Chapare Region in the yungas of the eastern Andean Cordillera de Cochabamba, Bolivia. Collecting localities range from approximately 300 m to >3200 m in elevation. The specimens pertain to 23 species, probably 10 of which are undescribed. We describe four new species of frogs, one each in the genera Bufo, Centrolenella, Colostethus, and Hyla, and one new species of snake, genus Dipsas. We place Atelopus rugulosus in synonymy with A. tricolor.

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

    Directory of Open Access Journals (Sweden)

    Ashish Thomas

    Full Text Available 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.

  6. Ex situ diet influences the bacterial community associated with the skin of red-eyed tree frogs (Agalychnis callidryas.

    Directory of Open Access Journals (Sweden)

    Rachael E Antwis

    Full Text Available Amphibians support symbiotic bacterial communities on their skin that protect against a range of infectious pathogens, including the amphibian chytrid fungus. The conditions under which amphibians are maintained in captivity (e.g. diet, substrate, enrichment in ex situ conservation programmes may affect the composition of the bacterial community. In addition, ex situ amphibian populations may support different bacterial communities in comparison to in situ populations of the same species. This could have implications for the suitability of populations intended for reintroduction, as well as the success of probiotic bacterial inoculations intended to provide amphibians with a bacterial community that resists invasion by the chytrid fungus. We aimed to investigate the effect of a carotenoid-enriched diet on the culturable bacterial community associated with captive red-eyed tree frogs (Agalychnis callidryas and make comparisons to bacteria isolated from a wild population from the Chiquibul Rainforest in Belize. We successfully showed carotenoid availability influences the overall community composition, species richness and abundance of the bacterial community associated with the skin of captive frogs, with A. callidryas fed a carotenoid-enriched diet supporting a greater species richness and abundance of bacteria than those fed a carotenoid-free diet. Our results suggest that availability of carotenoids in the diet of captive frogs is likely to be beneficial for the bacterial community associated with the skin. We also found wild A. callidryas hosted more than double the number of different bacterial species than captive frogs with very little commonality between species. This suggests frogs in captivity may support a reduced and diverged bacterial community in comparison to wild populations of the same species, which could have particular relevance for ex situ conservation projects.

  7. Optimal inverse magnetorheological damper modeling using shuffled frog-leaping algorithm–based adaptive neuro-fuzzy inference system approach

    Directory of Open Access Journals (Sweden)

    Xiufang Lin

    2016-08-01

    Full Text Available Magnetorheological dampers have become prominent semi-active control devices for vibration mitigation of structures which are subjected to severe loads. However, the damping force cannot be controlled directly due to the inherent nonlinear characteristics of the magnetorheological dampers. Therefore, for fully exploiting the capabilities of the magnetorheological dampers, one of the challenging aspects is to develop an accurate inverse model which can appropriately predict the input voltage to control the damping force. In this article, a hybrid modeling strategy combining shuffled frog-leaping algorithm and adaptive-network-based fuzzy inference system is proposed to model the inverse dynamic characteristics of the magnetorheological dampers for improving the modeling accuracy. The shuffled frog-leaping algorithm is employed to optimize the premise parameters of the adaptive-network-based fuzzy inference system while the consequent parameters are tuned by a least square estimation method, here known as shuffled frog-leaping algorithm-based adaptive-network-based fuzzy inference system approach. To evaluate the effectiveness of the proposed approach, the inverse modeling results based on the shuffled frog-leaping algorithm-based adaptive-network-based fuzzy inference system approach are compared with those based on the adaptive-network-based fuzzy inference system and genetic algorithm–based adaptive-network-based fuzzy inference system approaches. Analysis of variance test is carried out to statistically compare the performance of the proposed methods and the results demonstrate that the shuffled frog-leaping algorithm-based adaptive-network-based fuzzy inference system strategy outperforms the other two methods in terms of modeling (training accuracy and checking accuracy.

  8. Evolution of vertebrate transient receptor potential vanilloid 3 channels: opposite temperature sensitivity between mammals and western clawed frogs.

    Directory of Open Access Journals (Sweden)

    Shigeru Saito

    2011-04-01

    Full Text Available Transient Receptor Potential (TRP channels serve as temperature receptors in a wide variety of animals and must have played crucial roles in thermal adaptation. The TRP vanilloid (TRPV subfamily contains several temperature receptors with different temperature sensitivities. The TRPV3 channel is known to be highly expressed in skin, where it is activated by warm temperatures and serves as a sensor to detect ambient temperatures near the body temperature of homeothermic animals such as mammals. Here we performed comprehensive comparative analyses of the TRPV subfamily in order to understand the evolutionary process; we identified novel TRPV genes and also characterized the evolutionary flexibility of TRPV3 during vertebrate evolution. We cloned the TRPV3 channel from the western clawed frog Xenopus tropicalis to understand the functional evolution of the TRPV3 channel. The amino acid sequences of the N- and C-terminal regions of the TRPV3 channel were highly diversified from those of other terrestrial vertebrate TRPV3 channels, although central portions were well conserved. In a heterologous expression system, several mammalian TRPV3 agonists did not activate the TRPV3 channel of the western clawed frog. Moreover, the frog TRPV3 channel did not respond to heat stimuli, instead it was activated by cold temperatures. Temperature thresholds for activation were about 16 °C, slightly below the lower temperature limit for the western clawed frog. Given that the TRPV3 channel is expressed in skin, its likely role is to detect noxious cold temperatures. Thus, the western clawed frog and mammals acquired opposite temperature sensitivity of the TRPV3 channel in order to detect environmental temperatures suitable for their respective species, indicating that temperature receptors can dynamically change properties to adapt to different thermal environments during evolution.

  9. The Change of a Medically Important Genus: Worldwide Occurrence of Genetically Diverse Novel Brucella Species in Exotic Frogs.

    Science.gov (United States)

    Scholz, Holger C; Mühldorfer, Kristin; Shilton, Cathy; Benedict, Suresh; Whatmore, Adrian M; Blom, Jochen; Eisenberg, Tobias

    2016-01-01

    The genus Brucella comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for Brucella. In this study, however, we show that novel Brucella species are distributed among exotic frogs worldwide. Comparative recA gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical Brucella species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like B. inopinata, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical Brucella species revealed additional genetic material, absent from classical Brucella species but present in Ochrobactrum, the closest genetic neighbor of Brucella, and in other soil associated genera of the Alphaproteobacteria. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical Brucella species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic Brucella with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer.

  10. Perceived Synchrony of Frog Multimodal Signal Components Is Influenced by Content and Order.

    Science.gov (United States)

    Taylor, Ryan C; Page, Rachel A; Klein, Barrett A; Ryan, Michael J; Hunter, Kimberly L

    2017-10-01

    Multimodal signaling is common in communication systems. Depending on the species, individual signal components may be produced synchronously as a result of physiological constraint (fixed) or each component may be produced independently (fluid) in time. For animals that rely on fixed signals, a basic prediction is that asynchrony between the components should degrade the perception of signal salience, reducing receiver response. Male túngara frogs, Physalaemus pustulosus, produce a fixed multisensory courtship signal by vocalizing with two call components (whines and chucks) and inflating a vocal sac (visual component). Using a robotic frog, we tested female responses to variation in the temporal arrangement between acoustic and visual components. When the visual component lagged a complex call (whine + chuck), females largely rejected this asynchronous multisensory signal in favor of the complex call absent the visual cue. When the chuck component was removed from one call, but the robofrog inflation lagged the complex call, females responded strongly to the asynchronous multimodal signal. When the chuck component was removed from both calls, females reversed preference and responded positively to the asynchronous multisensory signal. When the visual component preceded the call, females responded as often to the multimodal signal as to the call alone. These data show that asynchrony of a normally fixed signal does reduce receiver responsiveness. The magnitude and overall response, however, depend on specific temporal interactions between the acoustic and visual components. The sensitivity of túngara frogs to lagging visual cues, but not leading ones, and the influence of acoustic signal content on the perception of visual asynchrony is similar to those reported in human psychophysics literature. Virtually all acoustically communicating animals must conduct auditory scene analyses and identify the source of signals. Our data suggest that some basic

  11. Effect of vanadate and of removal of extracellular Ca2+ and Na+ on tension development and 45Ca efflux in rat and frog myocardium

    DEFF Research Database (Denmark)

    Gesser, H; Bonefeld-Jørgensen, Eva Cecilie

    1983-01-01

    Vanadate in the range 0-5 mM has positive inotropic effects on myocardial strips of frog and to a lesser extent on those of rat. Inhibiting the sarcolemmal Na+, Ca2+ exchange by a solution free of Ca2+ and Na+ caused a drop in 45Ca efflux and a transient increase in resting tension. These effects...... were more expressed for the frog than for the rat myocardium, which suggests that the Na+ for Ca2+ exchange across the cell membrane is more important in the frog than in the rat myocardium. A subsequent addition of vanadate at 2 or 5 mM had no effect on 45Ca efflux, while it increased the resting...... tension. This increase was higher for the frog than for the rat myocardium. These results suggest that the inotropic effects of vanadate may be due to an effect on membrane-bound Ca2+-ATPase....

  12. Diversity, external morphology and ‘reverse taxonomy’ in the specialized tadpoles of Malagasy river bank frogs of the subgenus Ochthomantis (genus Mantidactylus)

    NARCIS (Netherlands)

    Randrianiaina, R.-D.; Strauß, A.; Glos, J.; Glaw, F.; Vences, M.

    2011-01-01

    We provide detailed morphological descriptions of the tadpoles of Malagasy river bank frogs of the subgenera Ochthomantis and Maitsomantis (genus Mantidactylus, family Mantellidae), and data on relative abundance and habitat preferences of Ochthomantis species from Ranomafana National Park in

  13. Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Science.gov (United States)

    Lind, A.J.; Spinks, P.Q.; Fellers, G.M.; Shaffer, H.B.

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b and ND2 fragments for 77 individuals from 34 localities using phylogenetic and population genetic analyses. We constructed gene trees using maximum likelihood and Bayesian inference, and quantified genetic variance (using AMOVA and partial Mantel tests) within and among hydrologic regions and river basins. Several moderately supported, geographically-cohesive mtDNA clades were recovered for R. boylii. While genetic variation was low among populations in the largest, most inclusive clade, samples from localities at the edges of the geographic range demonstrated substantial genetic divergence from each other and from more central populations. Hydrologic regions and river basins, which represent likely dispersal corridors for R. boylii, accounted for significant levels of genetic variation. These results suggest that both rivers and larger hydrologic and geographic regions should be used in conservation planning for R. boylii. ?? 2010 US Government.

  14. First estimates of the probability of survival in a small-bodied, high-elevation frog (Boreal Chorus Frog, Pseudacris maculata), or how historical data can be useful

    Science.gov (United States)

    Muths, Erin L.; Scherer, R. D.; Amburgey, S. M.; Matthews, T.; Spencer, A. W.; Corn, P.S.

    2016-01-01

    In an era of shrinking budgets yet increasing demands for conservation, the value of existing (i.e., historical) data are elevated. Lengthy time series on common, or previously common, species are particularly valuable and may be available only through the use of historical information. We provide first estimates of the probability of survival and longevity (0.67–0.79 and 5–7 years, respectively) for a subalpine population of a small-bodied, ostensibly common amphibian, the Boreal Chorus Frog (Pseudacris maculata (Agassiz, 1850)), using historical data and contemporary, hypothesis-driven information–theoretic analyses. We also test a priori hypotheses about the effects of color morph (as suggested by early reports) and of drought (as suggested by recent climate predictions) on survival. Using robust mark–recapture models, we find some support for early hypotheses regarding the effect of color on survival, but we find no effect of drought. The congruence between early findings and our analyses highlights the usefulness of historical information in providing raw data for contemporary analyses and context for conservation and management decisions.

  15. Altered Immune Response of the Rice Frog Fejervarya limnocharis Living in Agricultural Area with Intensive Herbicide Utilization at Nan Province, Thailand

    Directory of Open Access Journals (Sweden)

    Khattapan Jantawongsri

    2015-01-01

    Full Text Available Herbicides (atrazine, glyphosate and paraquat have been intensively used in Nan Province for a long time. Prior observations indicated that herbicide contamination and adverse health effects were found on the rice frog Fejervarya limnocharis living in paddy fields at Nan Province. Contamination of herbicides may influence disease emergence by acting directly or indirectly upon the immune system of amphibian or by causing disruptions in homeostasis, it is thus interesting to investigate potential effects of herbicide contamination in Nan Province on immune responses of the rice frog living in agricultural areas. Frogs were caught from a paddy field with no history of herbicide utilization (reference site and a paddy field with intensive herbicide utilization (contaminated site during 2010-2011. After dissection, frog livers were fixed in 10% neutral buffer formalin, processed by paraffin method and stained with hematoxylin and eosin. Number of melanomacrophage and melanomacrophage center (MMC were counted under a light microscope and used as markers of non-specific immune response. It was found that there was no significant sex-related difference in these numbers. However, there were significant seasonal differences in these numbers in both reference and contaminated site frogs, suggesting that seasonal difference in herbicide usage tend to affect frog's immune system in agricultural areas. Furthermore, numbers of melanomacrophage and MMC in early wet, late wet and early dry periods were markedly higher in the contaminated site frogs compared to those of the reference site frogs. The observation on amphibian's immune response to environmental contaminants could indicate the impacts of herbicide utilization on other vertebrates, as well as its role in amphibian declines.

  16. A new genus and two new species of minute leptodactylid frogs from northern South America, with comments upon Phyzelaphryne (Amphibia: Anura: Leptodactylidae)

    OpenAIRE

    Hoogmoed, M.S.; Lescure, J.

    1984-01-01

    The synonymisation of Phyzelaphryne miriamae Heyer with Eleutherodactylus nigrovittatus Andersson is denied and it is shown that both species are quite distinct in numerous characters. A new genus (Adelophryne) of minute leptodactylid frogs with pointed discs on the toes and a distinctly reduced fourth finger, containing two new species (A. adiastola spec. nov. and A. gutturosa spec. nov.) is described from northern South America. A key to separate the diminutive leptodactylid frogs with poin...

  17. DNA barcoding and the identification of tree frogs (Amphibia: Anura: Rhacophoridae).

    Science.gov (United States)

    Dang, Ning-Xin; Sun, Feng-Hui; Lv, Yun-Yun; Zhao, Bo-Han; Wang, Ji-Chao; Murphy, Robert W; Wang, Wen-Zhi; Li, Jia-Tang

    2016-07-01

    The DNA barcoding gene COI (cytochrome c oxidase subunit I) effectively identifies many species. Herein, we barcoded 172 individuals from 37 species belonging to nine genera in Rhacophoridae to test if the gene serves equally well to identify species of tree frogs. Phenetic neighbor joining and phylogenetic Bayesian inference were used to construct phylogenetic trees, which resolved all nine genera as monophyletic taxa except for Rhacophorus, two new matrilines for Liuixalus, and Polypedates leucomystax species complex. Intraspecific genetic distances ranged from 0.000 to 0.119 and interspecific genetic distances ranged from 0.015 to 0.334. Within Rhacophorus and Kurixalus, the intra- and interspecific genetic distances did not reveal an obvious barcode gap. Notwithstanding, we found that COI sequences unambiguously identified rhacophorid species and helped to discover likely new cryptic species via the synthesis of genealogical relationships and divergence patterns. Our results supported that COI is an effective DNA barcoding marker for Rhacophoridae.

  18. Feeding ecology of the endemic rain frog Pristimantis jubatus (craugastoridae) in Munchique national park, Colombia

    International Nuclear Information System (INIS)

    Garcia, Juan Carlos; Velasquez, Leonardo Lucas; Cardenas Henao, Heiber; Posso Gomez, Carmen Elisa

    2012-01-01

    We studied the diet of the rain frog Pristimantis jubatus based on stomach and intestinal contents of 29 individuals from three different localities at Munchique National Park, Colombia. The diet was composed exclusively of arthropods, comprising a total of 66 preys which were in 32 taxa. The most frequent dietary items were Diptera and Hymenoptera, 19.7 % and 16.7 % respectively, followed by Araneae (15.1 %) and Coleoptera (12.1 %). Plant consumption was considered incidental because of its low frequency. This species showed no preference for any type of prey, with a high value of niche breadth (0.68) indicating a generalist diet. Adults and juveniles occupy different perch height. Habitat use and the variety of items found show P. jubatus as a species that can consume any kind of arthropod available in the strata of the forest where it is foraging.

  19. Loss of inducible photorepair in a frog cell line hypersensitive to solar UV light

    International Nuclear Information System (INIS)

    Chao, C.C.-K.

    1987-01-01

    The induction of enzymatic photorepair (EPR) in ICR 2A frog cells and a derived mutant cell line DRP36 hypersensitive to solar UV was studied. Using clonogenic assays, when induced wild-type cells demonstrated an 8-fold increase of EPR the mutant cells displayed a near-background level of inducible EPR. The constitutive EPR in mutant cells, however, was the same as in wild-type cells. A mixed culture of ICR 2A and DRP36 cells showed an intermediate inducible EPR depending upon the cell ratio. Inducible EPR was also detected at the DNA level in wild-type cells, but not in mutant cells. 29 refs.; 2 figs.; 2 tabs

  20. SEXUAL SELECTION. Irrationality in mate choice revealed by túngara frogs.

    Science.gov (United States)

    Lea, Amanda M; Ryan, Michael J

    2015-08-28

    Mate choice models derive from traditional microeconomic decision theory and assume that individuals maximize their Darwinian fitness by making economically rational decisions. Rational choices exhibit regularity, whereby the relative strength of preferences between options remains stable when additional options are presented. We tested female frogs with three simulated males who differed in relative call attractiveness and call rate. In binary choice tests, females' preferences favored stimulus caller B over caller A; however, with the addition of an inferior "decoy" C, females reversed their preferences and chose A over B. These results show that the relative valuation of mates is not independent of inferior alternatives in the choice set and therefore cannot be explained with the rational choice models currently used in sexual selection theory. Copyright © 2015, American Association for the Advancement of Science.

  1. Effects of triphenyltin on growth and development of the wood frog (Lithobates sylvaticus)

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Eric; Tompsett, Amber R. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); Giesy, John P. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK (Canada); Zoology Department, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI (United States); Department of Biology and Chemistry, and State Key Laboratory for Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing (China); Hecker, Markus [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); School of the Environment and Sustainability, University of Saskatchewan, Saskatoon, SK (Canada); Wiseman, Steve, E-mail: steve.wiseman@usask.ca [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada)

    2013-11-15

    Highlights: •Wood frogs (Lithobates sylvaticus) were exposed to 0.1, 1.0, or 5.0 μg TPT/L. •Environmental concentrations of TPT affected survival and development of wood frogs. •Mortality of larvae was 100% after 9 days of exposure to 5.0 μg TPT/L. •Effects on growth and development might have been due to effects on lipid metabolism. -- Abstract: Exposure to contaminants in the environment has been suggested as a contributing cause of ongoing declines in populations of amphibians reported in certain locations around the world. In the current study, responses of the wood frog (Lithobates sylvaticus) to exposure to triphenyltin (TPT), a commonly used fungicide, during the larval period were characterized. Exposure of L. sylvaticus to 0.1, 1.0, or 5.0 μg TPT/L significantly affected survival, growth, days to metamorphosis (DTM), and abundances of transcripts of genes of interest. After seven days of exposure there were no significant effects on survival, but masses and snout-ventral length (SVL) of larvae exposed to 5.0 μg TPT/L were significantly lesser than controls. Mortality of larvae after exposure to 5.0 μg TPT/L was 100% nine days after initiation of the experiment. Larvae exposed to 0.1 or 1.0 μg TPT/L were allowed to grow for 100 days or until they reached metamorphic climax, whichever occurred earlier. Mortality of wood frogs exposed to 1.0 μg TPT/L was 80%. The LC{sub 20} or LC{sub 50} after 100 days of exposure was 0.12 or 0.34 μg TPT/L, respectively. However, DTM of larvae that survived exposure to 1.0 μg TPT/L was significantly less than that of controls. Abundances of transcripts of retinoid-X-receptor (rxr) and perixosomal proliferation receptor gamma (pparγ) were significantly lesser in larvae exposed to either concentration of TPT for seven days. Also, abundances of transcripts of stearoyl-CoA desaturase-1 (scd1), fatty acid synthase (fas), lipoprotein lipase (lpl), and β-hydroxybutyrate dehydrogenase (β-hb-m) were lesser in

  2. Visual and acoustic signaling in three species of Brazilian nocturnal tree frogs (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    Luís Felipe Toledo

    2007-06-01

    Full Text Available Visual communication seems to be widespread among nocturnal anurans, however, reports of these behaviors in many Neotropical species are lacking. Therefore, we gathered information collected during several sporadic field expeditions in central and southern Brazil with three nocturnal tree frogs: Aplastodiscus perviridis, Hypsiboas albopunctatus and H. bischoffi. These species displayed various aggressive behaviors, both visual and acoustic, towards other males. For A. perviridis we described arm lifting and leg kicking; for H. albopunctatus we described the advertisement and territorial calls, visual signalizations, including a previously unreported behavior (short leg kicking, and male-male combat; and for H. bischoffiwe described the advertisement and fighting calls, toes and fingers trembling, leg lifting, and leg kicking. We speculate about the evolution of some behaviors and concluded that the use of visual signals among Neotropical anurans may be much more common than suggested by the current knowledge.

  3. Protective effect of taurine on the light-induced disruption of isolated frog rod outer segments

    International Nuclear Information System (INIS)

    Pasantes-Morales, H.; Ademe, R.M.; Quesada, O.

    1981-01-01

    Isolated frog rod outer segments (ROS) incubated in a Krebs-bicarbonate medium, and illuminated for 2 h, show a profound alteration in their structure. This is characterized by distention of discs, vesiculation, and a marked swelling. The light-induced ROS disruption requires the presence of bicarbonate and sodium chloride. Replacement of bicarbonate by TRIS or HEPES protects ROS structure. Also, substitution of sodium chloride by sucrose or choline chloride maintains unaltered the ROS structure. Deletion of calcium, magnesium, or phosphate does not modify the effect produced by illumination. An increased accumulation of labeled bicarbonate and tritiated water is observed in illuminated ROS, as compared with controls in the dark. The presence of taurine, GABA, or glycine, at concentrations of 5-25 mM, effectively counteracts the light-induced ROS disruption. Taurine (25 mM) reduces labeled bicarbonate and tritiated water levels to those observed in the dark incubated ROS

  4. Ecology of the bromeligenous frog Phyllodytes luteolus (Anura, Hylidae from three restinga remnants across Brazil's coast

    Directory of Open Access Journals (Sweden)

    Tatiana Motta-Tavares

    2016-03-01

    Full Text Available In this study, we analyzed diet, sexual dimorphism and bromeliad use in three populations of the hylid frog Phyllodytes luteolus from restinga habitats along the Brazilian coast. We found 13 arthropods categories in 161 stomachs. Ants and termites were the dominant prey items. The similar trophic niche across populations suggests this species has a conservative diet. We found sexual dimorphism regarding body size and jaw width. We recordedP. luteolus in five bromeliad species, but predominantly inAechmeablanchetiana (35.6% of individuals recorded. We recorded solitary individuals in 44% of occupied bromeliads, and never found two males sharing the same bromeliad. The data is suggestive that populations ofP. luteolus has a conservative diet independent of area, with ants and termites the being most relevant prey items. The sexual dimorphism in jaw and the solitary males may suggest that this species have territorial behavior.

  5. Effect of Methyl Parathion on Survival and Development of Tadpoles of Indian Cricket frog Fejervarya limnocharis

    Directory of Open Access Journals (Sweden)

    Hunasanahalli Puttaswamygowda Gurushankara

    2016-04-01

    Full Text Available Amphibian populations are declining due to various causes including pesticide contamination in natural habitat. We evaluated the effect of Methyl Parathion (MPT an organophosphate pesticide on survival and development of common paddy field frog Fejervarya limnocharis in a laboratory condition. Effect of 0 µg MPT/L, 500 µg MPT/L,1000 µg MPT/L, 1500 µg MPT/L, 2000 µg MPT/L and 3000 µg MPT/L was studied using static toxicity test for a duration of 28 days. MPT reduced the survival of tadpole. The mortality was increased with the increased concentration of pesticide. The development decreased with increased MPT concentrations. At higher concentrations, MPT induced slow development and tadpoles failed to metamorphose. It is assumed that slow development could affect the early larval life and amphibian population in the agroecosystem.

  6. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium

    DEFF Research Database (Denmark)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel

    2015-01-01

    Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore......, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated...... form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C...

  7. Paternal Effort in Relation to Acoustically Mediated Mate Choice in a Neotropical Frog

    Science.gov (United States)

    Pettitt, Beth Ann

    One aspect of communication not normally considered in studies of anuran amphibians involves the extent to which acoustic signals indicate the quality of parental care a male provides. My research examined this question in the golden rocket frog (Anomaloglossus beebei), a Neotropical dendrobatid that exhibits acoustically mediated mate choice and biparental care. I investigated the function of the male advertisement call of A. beebei in the context of female mate choice by testing the predictions of four hypotheses that have been proposed to explain the relationship between mate signals and male parental care quality. In addition, I conducted a series of studies on acoustic variability, female preferences for advertisement call traits and the importance of male parental care on offspring survival.

  8. Ecology of the bromeligenous frog Phyllodytes luteolus (Anura, Hylidae) from three restinga remnants across Brazil's coast.

    Science.gov (United States)

    Motta-Tavares, Tatiana; Maia-Carneiro, Thiago; Dantas, Leonardo F; Sluys, Monique Van; Hatano, Fábio H; Vrcibradic, Davor; Rocha, Carlos F D

    2016-03-01

    In this study, we analyzed diet, sexual dimorphism and bromeliad use in three populations of the hylid frog Phyllodytes luteolus from restinga habitats along the Brazilian coast. We found 13 arthropods categories in 161 stomachs. Ants and termites were the dominant prey items. The similar trophic niche across populations suggests this species has a conservative diet. We found sexual dimorphism regarding body size and jaw width. We recordedP. luteolus in five bromeliad species, but predominantly inAechmeablanchetiana (35.6% of individuals recorded). We recorded solitary individuals in 44% of occupied bromeliads, and never found two males sharing the same bromeliad. The data is suggestive that populations ofP. luteolus has a conservative diet independent of area, with ants and termites the being most relevant prey items. The sexual dimorphism in jaw and the solitary males may suggest that this species have territorial behavior.

  9. Identification and characterization of two dermorphins from skin extracts of the Amazonian frog Phyllomedusa bicolor.

    Science.gov (United States)

    Mignogna, G; Severini, C; Simmaco, M; Negri, L; Erspamer, G F; Kreil, G; Barra, D

    1992-05-11

    Skin extracts of South American hylid frogs of the subfamily Phyllomedusinae contain dermorphins and deltorphins, opioid heptapeptides highly selective for either mu or delta receptors. In all these peptides, a D-amino acid is present in the second position. The structure of the precursors for Ala-deltorphins was recently deduced from cloned cDNAs derived from skin of Phyllomedusa bicolor (Richter et al. (1990) Proc. Natl. Acad. Sci. USA 87, 4836-4839). From the amino acid sequence of these precursors, the existence of three peptides related to dermorphin could be predicted. From methanol extracts of skin of Ph. bicolor we have isolated two of these peptides, [Lys7]dermorphin-OH and [Trp4,Asn7]dermorphin-OH. The biological activity of these new dermorphins and their amidated counterparts is presented.

  10. Peptide secretion in the cutaneous glands of South American tree frog Phyllomedusa bicolor: an ultrastructural study.

    Science.gov (United States)

    Lacombe, C; Cifuentes-Diaz, C; Dunia, I; Auber-Thomay, M; Nicolas, P; Amiche, M

    2000-09-01

    The development of the dermal glands of the arboreal frog Phyllomedusa bicolor was investigated by immunocytochemistry and electron microscopy. The 3 types of glands (mucous, lipid and serous) differed in size and secretory activity. The mucous and serous glands were apparent in the tadpole skin, whereas the lipid glands developed later in ontogenesis. The peptide antibiotics dermaseptins and the D-amino acid-containing peptide opioids dermorphins and deltorphins are abundant in the skin secretions of P. bicolor. Although these peptides differ in their structure and activity they are derived from precursors that have very similar preproregions. We used an antibody to the common preproregion of preprodermaseptins and preprodeltorphins and immunofluorescence analysis to show that only the serous glands are specifically involved in the biosynthesis and secretion of dermaseptins and deltorphins. Scanning and transmission electron microscopy revealed that the serous glands of P bicolor have morphological features, especially the secretory granules, which differ from those of the glands in Xenopus laevis skin.

  11. Hydrophylax bahuvistara, a new species of fungoid frog (Amphibia: Ranidae from peninsular India

    Directory of Open Access Journals (Sweden)

    Anand D. Padhye

    2015-09-01

    Full Text Available Hydrophylax bahuvistara, a new species of fungoid frog, is described from peninsular India. It can be separated from its congeners based on a combination of characters including wider head, outline of snout in dorsal view truncated, finger and toe tips without lateroventral groove, foot moderately webbed, metatarsals of 4th and 5th toes closely set, outer metatarsal tubercle small, foot length less than or equal to half of snout vent length, dorsal parts of shank without glandular folds and sparse horny spinules, and heels touch each other when the legs are folded at right angles to the body.  Genetically, H. bahuvistara forms a monophyletic group with H. malabaricus as a sister clade separated by a raw distance of 4.0 to 4.5% in the 16s rRNA gene.  Morphometrically, H. bahuvistara forms a significantly different cluster from H. malabaricus and H. gracilis in Discriminant Analysis.  

  12. Diversity and phylogeography of Northeast Asian brown frogs allied to Rana dybowskii (Anura, Ranidae).

    Science.gov (United States)

    Yang, Bao-Tian; Zhou, Yu; Min, Mi-Sook; Matsui, Masafumi; Dong, Bing-Jun; Li, Pi-Peng; Fong, Jonathan J

    2017-07-01

    We investigated the species diversity and phylogeography of the Northeast Asian brown frogs allied to Rana dybowskii (the R. dybowskii species complex: R. dybowskii, R. pirica, and R. uenoi) using four mitochondrial and three nuclear loci. Phylogenetic analyses confirmed the existence of three distinct species in this complex; using extensive molecular data, we confirm the validity of Rana uenoi recognized as a distinct species, and infer R. dybowskii and R. pirica to be sister species. Also, we included populations from previously unsampled regions in Northeast China, and identified them to be R. dybowskii. While many species in Northeast Asia diverged due to Pleistocene glaciation, divergence-dating analyses inferred older, Miocene speciation in the R. dybowskii species complex. Ancestral area reconstruction identified the orogenic movement of the Changbai Mountain Range and the opening of the Sea of Japan/East Sea being major events influencing allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Modification of permeability of frog perineurium to [14C]-sucrose by stretch and hypertonicity

    International Nuclear Information System (INIS)

    Weerasuriya, A.; Rapoport, S.I.; Taylor, R.E.

    1979-01-01

    An in vitro method has been developed to determine quantitatively the permeability of the perineurium to radiotracers at room temperature. The permeability to [ 14 C]sucrose of the isolated perineurium of the sciatic nerve of the frog, Rana pipiens, was measured at rest length, when the perineurium was stretched and after the perineurium had been subjected to hypertonic treatment. Mean permeability at rest length was calculated to be 5.6 +- 0.27 (S.E.M., n=45)x10 -7 cm/sec, and both stretch and hypertonic treatment increased the permeability. A 10% stretch increased permeability reversibly, whereas a 20% stretch or immersion of the perineurium in a hypertonic bath increased permeability irreversibly. Altered permeability under these conditions might be related to changes in the ultrastructure of tight junctions in the perineurium. (Auth.)

  14. Influences of different thermal processings in milk, bovine meat and frog protein structure.

    Science.gov (United States)

    Coura Oliveira, Tatiana; Lopes Lima, Samuel; Bressan, Josefina

    2013-01-01

    Several studies have associated the digestibility of proteins to its imunogenic potential. Though, it was objectified to evaluate the impact of the thermal processing with high and low temperatures on the proteins structure of three types of foods, by means of the digestibility in vitro and electroforesis en gel de poliacrilamida. The pasteurize was observed in such a way, firing 95 ºC during 15 minutes, how much freeze dried causes qualitative and quantitative modifications of constituent proteins of the food. The most sensible proteins to the increasing thermal processing order were beef, frog meat, and the last, cow milk. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  15. A new diminutive frog species of Adelophryne (Amphibia: Anura: Eleutherodactylidae) from the Atlantic Forest, southeastern Brazil.

    Science.gov (United States)

    Lourenço-de-Moraes, Ricardo; Ferreira, Rodrigo Barbosa; Fouquet, Antoine; Bastos, Rogério Pereira

    2014-08-04

    The genus Adelophryne is composed of diminutive frogs occurring in northern Amazonia and the Atlantic Forest. Herein we describe a new species of Adelophryne found in the leaf litter of primary and secondary forests in the mountainous region of Espírito Santo state, southeastern Brazil. The new species is characterized by its small body size, two phalanges in the finger IV, and a glandular ridge line that runs from the posterior part of eye to the insertion of the forelimb. This species is sensitive to edge effect and conversion of native forest into coffee and Eucalyptus plantations and may be listed as Endangered (EN) under B1ab(iii) criteria of the IUCN Red List.

  16. Effects of triphenyltin on growth and development of the wood frog (Lithobates sylvaticus)

    International Nuclear Information System (INIS)

    Higley, Eric; Tompsett, Amber R.; Giesy, John P.; Hecker, Markus; Wiseman, Steve

    2013-01-01

    Highlights: •Wood frogs (Lithobates sylvaticus) were exposed to 0.1, 1.0, or 5.0 μg TPT/L. •Environmental concentrations of TPT affected survival and development of wood frogs. •Mortality of larvae was 100% after 9 days of exposure to 5.0 μg TPT/L. •Effects on growth and development might have been due to effects on lipid metabolism. -- Abstract: Exposure to contaminants in the environment has been suggested as a contributing cause of ongoing declines in populations of amphibians reported in certain locations around the world. In the current study, responses of the wood frog (Lithobates sylvaticus) to exposure to triphenyltin (TPT), a commonly used fungicide, during the larval period were characterized. Exposure of L. sylvaticus to 0.1, 1.0, or 5.0 μg TPT/L significantly affected survival, growth, days to metamorphosis (DTM), and abundances of transcripts of genes of interest. After seven days of exposure there were no significant effects on survival, but masses and snout-ventral length (SVL) of larvae exposed to 5.0 μg TPT/L were significantly lesser than controls. Mortality of larvae after exposure to 5.0 μg TPT/L was 100% nine days after initiation of the experiment. Larvae exposed to 0.1 or 1.0 μg TPT/L were allowed to grow for 100 days or until they reached metamorphic climax, whichever occurred earlier. Mortality of wood frogs exposed to 1.0 μg TPT/L was 80%. The LC 20 or LC 50 after 100 days of exposure was 0.12 or 0.34 μg TPT/L, respectively. However, DTM of larvae that survived exposure to 1.0 μg TPT/L was significantly less than that of controls. Abundances of transcripts of retinoid-X-receptor (rxr) and perixosomal proliferation receptor gamma (pparγ) were significantly lesser in larvae exposed to either concentration of TPT for seven days. Also, abundances of transcripts of stearoyl-CoA desaturase-1 (scd1), fatty acid synthase (fas), lipoprotein lipase (lpl), and β-hydroxybutyrate dehydrogenase (β-hb-m) were lesser in larvae exposed

  17. Environmental parameters affecting the structure of leaf-litter frog (Amphibia: Anura communities in tropical forests: a case study from an Atlantic Rainforest area in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Carla C. Siqueira

    2014-04-01

    Full Text Available Despite a recent increase of information on leaf litter frog communities from Atlantic rainforests, few studies have analyzed the relationship between environmental parameters and community structure of these animals. We analyzed the effects of some environmental factors on a leaf litter frog community at an Atlantic Rainforest area in southeastern Brazil. Data collection lasted ten consecutive days in January 2010, at elevations ranging between 300 and 520 m above sea level. We established 50 quadrats of 5 x 5 m on the forest floor, totaling 1,250 m² of sampled area, and recorded the mean leaf-litter depth and the number of trees within the plot, as well as altitude. We found 307 individuals belonging to ten frog species within the plots. The overall density of leaf-litter frogs estimated from the plots was 24.6 ind/100m², with Euparkerella brasiliensis (Parker, 1926, Ischnocnema guentheri (Steindachner, 1864, Ischnocnema parva (Girard, 1853 and Haddadus binotatus (Spix, 1824 presenting the highest estimated densities. Among the environmental variables analyzed, only altitude influenced the parameters of anuran community. Our results indicate that the study area has a very high density of forest floor leaf litter frogs at altitudes of 300-500 m. Future estimates of litter frog density might benefit from taking the local altitudinal variation into consideration. Neglecting such variation might result in underestimated/overestimated values if they are extrapolated to the whole area.

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

    Directory of Open Access Journals (Sweden)

    Lígia Pizzatto

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

  19. Severe IgE-mediated anaphylaxis following consumption of fried frog legs: definition of alpha-parvalbumin as the allergen in cause.

    Science.gov (United States)

    Hilger, C; Grigioni, F; Thill, L; Mertens, L; Hentges, F

    2002-11-01

    IgE-mediated allergic reactions to bullfrog and edible frog have been reported. The implicated allergens have not been defined so far. The frog material and the patient's serum from a case of severe food-induced anaphylaxis were used to define the implicated allergen at the protein and DNA level. Immunoblotting techniques and N-terminal protein microsequencing were used to define the allergen recognized by the patient's serum. Back translation from the identified protein sequence was used to design degenerated primers to amplify the allergen's cDNA by polymerase chain reaction (PCR). We defined the nucleotide sequence of the allergen from the frog of Indonesian origin that was consumed by the patient, and the homologous cDNA from Rana esculenta. Protein microsequencing revealed that the implicated frog allergen belonged to the parvalbumin family. cDNAs coding for alpha- and beta-parvalbumin of R. esculenta and Rana species were cloned. Recombinant proteins were expressed in Escherichia coli. The patient's serum IgE antibodies recognized parvalbumin prepared from frog muscle and recombinant alpha-parvalbumin from R. species but not from R. esculenta. Recombinant beta-parvalbumin was not recognized by the IgE antibodies. This work defines at the protein and DNA levels alpha-parvalbumin as the allergen implicated in a case of IgE-mediated anaphylaxis to frog muscle. It also shows that a protein belonging to the parvalbumin family is implicated in type I allergies outside the fish species.

  20. Modeling warming predicts a physiological threshold for the extinction of the living fossil frog Calyptocephalella gayi.

    Science.gov (United States)

    Vidal, Marcela A; Novoa-Muñoz, Francisco; Werner, Enrique; Torres, Cristian; Nova, Ricardo

    2017-10-01

    Global climate change will have a greater impact on ectotherms in tropical and subtropical communities than at higher latitudes, because ambient temperatures are closer to the upper thermal limits of species. Amphibian species are highly dependent on external weather conditions, and the effect of global warming on these has been evaluated recently. The Great Chilean frog (Calyptocephalella gayi) is an endemic, monotypic species and genus whose conservation status is considered Vulnerable because of high extraction pressure for human consumption, lack of regulatory measures and comprehension by its consumers. Their populations have also declined due to the loss and destruction of their habitats. C. gayi has not been considered as an object of physiological study, so this large species is not known as one that can adapt to current environmental changes. In this study we analyze the thermoregulatory capacity and thermal efficiency of C. gayi to determine its potential for climatic adaptation. The results indicate that this species is strictly a thermal-conformer; its thermal efficiency and its ability to withstand high temperatures allow it to sustain itself under a climate change scenario, however, it has thermal constraints that do not allow it to withstand temperatures greater than 30°C. By modeling its ontogenetic conditions mathematically, we project that the larvae are not in danger, although there is a group of around 4% which is very close to 30°C, which is the highest temperature recorded for the species. However, about 40% of subadults and approximately 47% of adult frogs will not survive the change of ~7°C projected for the following 85 years, which will affect future generations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Inhibition by TRPA1 agonists of compound action potentials in the frog sciatic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, Akitomo; Ohtsubo, Sena; Fujita, Tsugumi; Kumamoto, Eiichi, E-mail: kumamote@cc.saga-u.ac.jp

    2013-04-26

    Highlights: •TRPA1 agonists inhibited compound action potentials in frog sciatic nerves. •This inhibition was not mediated by TRPA1 channels. •This efficacy was comparable to those of lidocaine and cocaine. •We found for the first time an ability of TRPA1 agonists to inhibit nerve conduction. -- Abstract: Although TRPV1 and TRPM8 agonists (vanilloid capsaicin and menthol, respectively) at high concentrations inhibit action potential conduction, it remains to be unknown whether TRPA1 agonists have a similar action. The present study examined the actions of TRPA1 agonists, cinnamaldehyde (CA) and allyl isothiocyanate (AITC), which differ in chemical structure from each other, on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method. CA and AITC concentration-dependently reduced the peak amplitude of the CAP with the IC{sub 50} values of 1.2 and 1.5 mM, respectively; these activities were resistant to a non-selective TRP antagonist ruthenium red or a selective TRPA1 antagonist HC-030031. The CA and AITC actions were distinct in property; the latter but not former action was delayed in onset and partially reversible, and CA but not AITC increased thresholds to elicit CAPs. A CAP inhibition was seen by hydroxy-α-sanshool (by 60% at 0.05 mM), which activates both TRPA1 and TRPV1 channels, a non-vanilloid TRPV1 agonist piperine (by 20% at 0.07 mM) and tetrahydrolavandulol (where the six-membered ring of menthol is opened; IC{sub 50} = 0.38 mM). It is suggested that TRPA1 agonists as well as TRPV1 and TRPM8 agonists have an ability to inhibit nerve conduction without TRP activation, although their agonists are quite different in chemical structure from each other.

  2. Developments in the design of the PS Frog Mk 5 wave energy converter

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, A.P.; Bradshaw, A.; Meadowcroft, J.A.C.; Aggidis, G. [Department of Engineering, Lancaster University Renewable Energy Group, Lancaster LA1 4YR (United Kingdom)

    2006-02-01

    This paper describes one of the innovative wave energy converters under development by the Lancaster University Renewable Energy Group. An offshore point-absorber wave energy converter, PS Frog Mk 5 consists of a large buoyant paddle with an integral ballasted 'handle' hanging below it. The waves act on the blade of the paddle and the ballast beneath provides the necessary reaction. When the WEC is pitching, power is extracted by partially resisting the sliding of a power-take-off mass, which moves in guides above sea level. Totally enclosed in a steel hull, with no external moving parts, PS Frog Mk. 5 is at least as robust as a ship and the survivability of the device is currently under investigation, though such work is beyond the scope of this paper. Such a device could be very economic in terms of power output per unit of capital cost. New inventive steps with experimental results and computer studies have led to promising improvements to the hull shape. The WEC is maintained in a resonant state by the use of special means to maintain a high dynamic magnifier in irregular seas. A robust feedback control system has been developed to ensure stability and maintain efficient power take-off. Some of these developments are described and illustrated with the results of computer simulations that show power outputs and device motion over a range of conditions. It is shown that useful advances have been made, with the power capture bordering on 2MW in an increasing proportion of sea states. (author)

  3. Aquatic life at high altitude: respiratory adaptations in the Lake Titicaca frog, Telmatobius culeus.

    Science.gov (United States)

    Hutchison, V H; Haines, H B; Engbretson, G

    1976-07-01

    Telmatobius culeus has a combination of behavioral, morphological and physiological adaptations which allows an aquatic life in cool (10 degrees C) O2-saturated (at 100 mm Hg) waters at high altitude (3812 m). The skin surgace area is increased by pronounced folds and the cutaneous capillaries penetrate to the outer layers of the skin. The erythrocyte volume (394 mu3) is the smallest reported for amphibians. The P50 (15.6 at ph 7.65 and 10 degrees C) is the lowest, and the erythrocyte count (729 - 103/mm3) the highest for an anuran. The O2 capacity (11.7 vol%), hemoglobin (8.1 g/100 ml), hemoglobin concentration (0.281 pg/mu3) and hematocrit (27.9%) measured at 18 degrees C and 3800 m are all elevated in comparison with most amphibians. The O2 dissociation curve is sigmoid (n = 2), the Bohr factor is small (deltalog P50/deltapH = -0.30) and the buffering capacity (-8.9 m M HCO3 - 1-1) is typical for an aquatic amphibian. The metabolic rate (14.1 mul -g-1-h-u) is the lowest reported for a frog and among amphibians only the giant salamanders (Amphiuma, Necturus and Siren) have lower values. If prevent from surfacing in hypoxic waters, the frogs ventilate the skin by "bobbing" behavior; if allowed to surface, they will ventilate the small lungs and the metabolic rate increases to 23 mul-g-1-h-1.

  4. Consequences of life history switch point plasticity for juvenile morphology and locomotion in the Túngara frog

    Directory of Open Access Journals (Sweden)

    Julie F. Charbonnier

    2015-09-01

    Full Text Available Many animals with complex life cycles can cope with environmental uncertainty by altering the timing of life history switch points through plasticity. Pond hydroperiod has important consequences for the fitness of aquatic organisms and many taxa alter the timing of life history switch points in response to habitat desiccation. For example, larval amphibians can metamorphose early to escape drying ponds. Such plasticity may induce variation in size and morphology of juveniles which can result in carry-over effects on jumping performance. To investigate the carry-over effects of metamorphic plasticity to pond drying, we studied the Túngara frog, Physalaemus pustulosus, a tropical anuran that breeds in highly ephemeral habitats. We conducted an outdoor field mesocosm experiment in which we manipulated water depth and desiccation and measured time and size at metamorphosis, tibiofibula length and jumping performance. We also conducted a complimentary laboratory experiment in which we manipulated resources, water depth and desiccation. In the field experiment, metamorphs from dry-down treatments emerged earlier, but at a similar size to metamorphs from constant depth treatments. In the laboratory experiment, metamorphs from the low depth and dry-down treatments emerged earlier and smaller. In both experiments, frogs from dry-down treatments had relatively shorter legs, which negatively impacted their absolute jumping performance. In contrast, reductions in resources delayed and reduced size at metamorphosis, but had no negative effect on jumping performance. To place these results in a broader context, we review past studies on carry-over effects of the larval environment on jumping performance. Reductions in mass and limb length generally resulted in lower jumping performance across juvenile anurans tested to date. Understanding the consequences of plasticity on size, morphology and performance can elucidate the linkages between life stages.

  5. Triclosan exposure alters postembryonic development in a Pacific tree frog (Pseudacris regilla) Amphibian Metamorphosis Assay (TREEMA)

    International Nuclear Information System (INIS)

    Marlatt, Vicki L.; Veldhoen, Nik; Lo, Bonnie P.; Bakker, Dannika; Rehaume, Vicki; Vallée, Kurtis; Haberl, Maxine; Shang, Dayue; Aggelen, Graham C. van; Skirrow, Rachel C.; Elphick, James R.; Helbing, Caren C.

    2013-01-01

    The Amphibian Metamorphosis Assay (AMA), developed for Xenopus laevis, is designed to identify chemicals that disrupt thyroid hormone (TH)-mediated biological processes. We adapted the AMA for use on an ecologically-relevant North American species, the Pacific tree frog (Pseudacris regilla), and applied molecular endpoints to evaluate the effects of the antibacterial agent, triclosan (TCS). Premetamorphic (Gosner stage 26–28) tadpoles were immersed for 21 days in solvent control, 1.5 μg/L thyroxine (T 4 ), 0.3, 3 and 30 μg/L (nominal) TCS, or combined T 4 /TCS treatments. Exposure effects were scored by morphometric (developmental stage, wet weight, and body, snout-vent and hindlimb lengths) and molecular (mRNA abundance using quantitative real time polymerase chain reaction) criteria. T 4 treatment alone accelerated development concomitant with altered levels of TH receptors α and β, proliferating cell nuclear antigen, and gelatinase B mRNAs in the brain and tail. We observed TCS-induced perturbations in all of the molecular and morphological endpoints indicating that TCS exposure disrupts coordination of postembryonic tadpole development. Clear alterations in molecular endpoints were evident at day 2 whereas the earliest morphological effects appeared at day 4 and were most evident at day 21. Although TCS alone (3 and 30 μg/L) was protective against tadpole mortality, this protection was lost in the presence of T 4 . The Pacific tree frog is the most sensitive species examined to date displaying disruption of TH-mediated development by a common antimicrobial agent.

  6. Triclosan exposure alters postembryonic development in a Pacific tree frog (Pseudacris regilla) Amphibian Metamorphosis Assay (TREEMA)

    Energy Technology Data Exchange (ETDEWEB)

    Marlatt, Vicki L. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Veldhoen, Nik [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada); Lo, Bonnie P. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Bakker, Dannika; Rehaume, Vicki; Vallee, Kurtis [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada); Haberl, Maxine; Shang, Dayue; Aggelen, Graham C. van; Skirrow, Rachel C. [Pacific and Yukon Laboratory for Environmental Testing, Emergencies Operational Analytical Laboratories and Research Support Division, Environment Canada, 2645 Dollarton Highway, North Vancouver, B.C. V7H 1B1 (Canada); Elphick, James R. [Nautilus Environmental, 8864 Commerce Court, Burnaby, B.C. V5A 4N7 (Canada); Helbing, Caren C., E-mail: chelbing@uvic.ca [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 Stn CSC, Victoria, B.C. V8W 3P6 (Canada)

    2013-01-15

    The Amphibian Metamorphosis Assay (AMA), developed for Xenopus laevis, is designed to identify chemicals that disrupt thyroid hormone (TH)-mediated biological processes. We adapted the AMA for use on an ecologically-relevant North American species, the Pacific tree frog (Pseudacris regilla), and applied molecular endpoints to evaluate the effects of the antibacterial agent, triclosan (TCS). Premetamorphic (Gosner stage 26-28) tadpoles were immersed for 21 days in solvent control, 1.5 {mu}g/L thyroxine (T{sub 4}), 0.3, 3 and 30 {mu}g/L (nominal) TCS, or combined T{sub 4}/TCS treatments. Exposure effects were scored by morphometric (developmental stage, wet weight, and body, snout-vent and hindlimb lengths) and molecular (mRNA abundance using quantitative real time polymerase chain reaction) criteria. T{sub 4} treatment alone accelerated development concomitant with altered levels of TH receptors {alpha} and {beta}, proliferating cell nuclear antigen, and gelatinase B mRNAs in the brain and tail. We observed TCS-induced perturbations in all of the molecular and morphological endpoints indicating that TCS exposure disrupts coordination of postembryonic tadpole development. Clear alterations in molecular endpoints were evident at day 2 whereas the earliest morphological effects appeared at day 4 and were most evident at day 21. Although TCS alone (3 and 30 {mu}g/L) was protective against tadpole mortality, this protection was lost in the presence of T{sub 4}. The Pacific tree frog is the most sensitive species examined to date displaying disruption of TH-mediated development by a common antimicrobial agent.

  7. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot

    Science.gov (United States)

    Hirschfeld, Mareike; Blackburn, David C.; Doherty-Bone, Thomas M.; Gonwouo, LeGrand Nono; Ghose, Sonia; Rödel, Mark-Oliver

    2016-01-01

    Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004–2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon’s frog diversity. PMID:27149624

  8. Metal levels in southern leopard frogs from the Savannah River Site: location and body compartment effects.

    Science.gov (United States)

    Burger, J; Snodgrass, J

    2001-06-01

    Tadpoles have been proposed as useful bioindicators of environmental contamination; yet, recently it has been shown that metal levels vary in different body compartments of tadpoles. Metals levels are higher in the digestive tract of bullfrog (Rana catesbeiana) tadpoles, which is usually not removed during such analysis. In this paper we examine the heavy metal levels in southern leopard frog (R. utricularia) tadpoles from several wetlands at the Savannah River Site and test the null hypotheses that (1) there are no differences in metal levels in different body compartments of the tadpoles, including the digestive tract; (2) there are no differences in heavy metal levels among different wetlands; and (3) there are no differences in the ratio of metals in the tail/body and in the digestive tract/body as a function of metal or developmental stage as indicated by body weight. Variations in heavy metal levels were explained by wetland and body compartment for all metals and by tadpole weight for selenium and manganese. In all cases, levels of metals were higher in the digestive tract than in the body or tail of tadpoles. Metal levels were highest in a wetland that had been remediated and lowest in a wetland that was never a pasture or remediated (i.e., was truly undisturbed). Although tadpoles are sometimes eaten by fish and other aquatic predators, leopard frogs usually avoid laying their eggs in ponds with such predators. However, avian predators will eat them. These data suggest that tadpoles can be used as bioindicators of differences in metal levels among wetlands and as indicators of potential exposure for higher-trophic-level organisms, but that to assess effects on the tadpoles themselves, digestive tracts should be removed before analysis. Copyright 2001 Academic Press.

  9. Within-population variation in ejaculate characteristics in a prolonged breeder, Peron's tree frog, Litoria peronii

    Science.gov (United States)

    Sherman, Craig D. H.; Uller, Tobias; Wapstra, Erik; Olsson, Mats

    2008-11-01

    Sperm number is often a good predictor of success in sperm competition; however, it has become increasingly clear that, for some species, variation in probability of paternity cannot be explained by sperm number alone. Intraspecific variation in ejaculate characteristics, such as the number of viable sperm and sperm longevity, may play an equally important role in determining fertilization success. Here, we assess variation among ejaculates in three factors that may contribute to fertilization success (number of sperm per ejaculate, viability, and longevity), in a population of Peron’s tree frog ( Litoria peronii). We detected large variation among males in the number of sperm per ejaculate and the proportion of viable sperm within ejaculates, which could not be explained by variation in either male size or body condition. However, the proportion of viable sperm released by males increased over the season. Finally, we assessed sperm longevity (proportion viable sperm determined using a dual-fluorochrome vital dye) at two different temperatures. At 23°C, on average, 75% of sperm remained viable after 2 h, but there were significant differences amongst males with the percentage of viable sperm ranging from 43% to 95%. For sperm incubated at 4°C, ejaculates varied fivefold in sperm longevity with some males having 50% viable sperm after 5 days. Our data suggest that ejaculate characteristics (sperm number, viability, and longevity) vary widely in Peron’s tree frog and may therefore play an important role in determining siring success both in the presence and absence of sperm competition. We discuss the results in relation to selection on ejaculate traits via natural and sexual selection in this and other amphibians.

  10. Comparative microhabitat characteristics at oviposition sites of the California red-legged frog (Rana draytonii)

    Science.gov (United States)

    Alvarez, Jeff A.; Cook, David G.; Yee, Julie L.; van Hattem, Michael G.; Fong, Darren R.; Fisher, Robert N.

    2013-01-01

    We studied the microhabitat characteristics of 747 egg masses of the federally-threatened Rana draytonii (California red-legged frog) at eight sites in California. our study showed that a broad range of aquatic habitats are utilized by ovipositing R. draytonii, including sites with perennial and ephemeral water sources, natural and constructed wetlands, lentic and lotic hydrology, and sites surrounded by protected lands and nested within modified urban areas. We recorded 45 different egg mass attachment types, although the use of only a few types was common at each site. These attachment types ranged from branches and roots of riparian trees, emergent and submergent wetland vegetation, flooded upland grassland/ruderal vegetation, and debris. eggs were deposited in relatively shallow water (mean 39.7 cm) when compared to maximum site depths. We found that most frogs in artificial pond, natural creek, and artificial channel habitats deposited egg masses within one meter of the shore, while egg masses in a seasonal marsh averaged 27.3 m from the shore due to extensive emergent vegetation. Rana draytonii appeared to delay breeding in lotic habitats and in more inland sites compared to lentic habitats and coastal sites. eggs occurred as early as mid-december at a coastal artificial pond and as late as mid-April in an inland natural creek. We speculate that this delay in breeding may represent a method of avoiding high-flow events and/or freezing temperatures. Understanding the factors related to the reproductive needs of this species can contribute to creating, managing, or preserving appropriate habitat, and promoting species recovery.

  11. Detritus Quality and Locality Determines Survival and Mass, but Not Export, of Wood Frogs at Metamorphosis.

    Directory of Open Access Journals (Sweden)

    Joseph R Milanovich

    Full Text Available Single-site experiments have demonstrated detritus quality in wetlands can have strongly negative, neutral, and even positive influences on wildlife. However, an examination of the influence of detritus quality across several regions is lacking and can provide information on whether impacts from variation in detritus quality are consistent across species with wide ranges. To address this gap in regional studies we examined effects of emergent and allochthonous detritus of different nutrient qualities on amphibians and assessed a mechanism that may contribute to potential impacts. We used aquatic mesocosms to raise wood frogs (Rana sylvatica from two regions of the United States with whole plants from purple loosestrife (Lythrum salicaria, leaf litter from native hardwood trees, and a mixture of both. We examined several metrics of amphibian fitness and life history, including survival, number of days to metamorphosis, and size at metamorphosis. Further, we quantified whether the effects of detritus type could translate to variation in anuran biomass or standing stock of nitrogen or phosphorus export. Our results show detritus with high nutrient quality (purple loosestrife negatively influenced survival of wood frogs, but increased size of metamorphic individuals in two different regions of the United States. Despite the decrease in survival, the increase in size of post-metamorphic anurans raised with high quality detritus resulted in anuran biomass and standing stock of N and P export being similar across treatments at both locations. These results further demonstrate the role of plant quality in shaping wetland ecosystem dynamics, and represent the first demonstration that effects are consistent within species across ecoregional boundaries.

  12. Reproductive effort and the egg number vs. size trade-off in Physalaemus frogs (Anura: Leiuperidae)

    Science.gov (United States)

    Camargo, Arley; Sarroca, Macarena; Maneyro, Raúl

    2008-09-01

    Patterns of reproductive allocation are expected to differ between species according to temporally and spatially variable costs of reproduction. Even when reproductive allocation patterns are the same, species can also differ in how the reproductive effort is allocated between offspring number and size. In this study, we compared the reproductive allocation patterns and the offspring number vs. size trade-off in two frog species, Physalaemus biligonigerus and P. gracilis, using bivariate (standardized major axis) and multiple linear regressions. Both species showed a common slope between body size and reproductive effort and thus a similar allocation pattern although P. biligonigerus has a larger body size (shift along common slope) and makes a lower reproductive effort (shift in intercept) than P. gracilis. We suggest that similar allocation patterns may be related to the shared phenologies of these frogs and that the differences in reproductive effort could represent either an adaptive shift (e.g., change in body space for the clutch) or a historical constraint. There was a negative correlation between fecundity and egg size in P. biligonigerus but not in P. gracilis as predicted by the acquisition-allocation model (Y-model). This study constitutes the first valid test of the Y-model based on recent predictions derived for the trade-off between offspring size vs. number. We conclude that future studies should compare reproductive allocation patterns between species using tests of allometric slopes with appropriate phylogenetic control to detect both adaptive shifts in allocation strategies and correlations with other life-history traits.

  13. Dramatic Declines of Montane Frogs in a Central African Biodiversity Hotspot.

    Directory of Open Access Journals (Sweden)

    Mareike Hirschfeld

    Full Text Available Amphibian populations are vanishing worldwide. Declines and extinctions of many populations have been attributed to chytridiomycosis, a disease induced by the pathogenic fungus Batrachochytrium dendrobatidis (Bd. In Africa, however, changes in amphibian assemblages were typically attributed to habitat change. We conducted a retrospective study utilizing field surveys from 2004-2012 of the anuran faunas on two mountains in western Cameroon, a hotspot of African amphibian diversity. The number of species detected was negatively influenced by year, habitat degradation, and elevation, and we detected a decline of certain species. Because another study in this region revealed an emergence of Bd in 2008, we screened additional recent field-collected samples and also pre-decline preserved museum specimens for the presence of Bd supporting emergence before 2008. When comparing the years before and after Bd detection, we found significantly diminished frog species richness and abundance on both mountains after Bd emergence. Our analyses suggest that this may be the first disease-driven community-level decline in anuran biodiversity in Central Africa. The disappearance of several species known to tolerate habitat degradation, and a trend of stronger declines at higher elevations, are consistent with Bd-induced declines in other regions. Not all species decreased; populations of some species remained constant, and others increased after the emergence of Bd. This variation might be explained by species-specific differences in infection probability. Increased habitat protection and Bd-mitigation strategies are needed for sustaining diverse amphibian communities such as those on Mt. Manengouba, which contains nearly half of Cameroon's frog diversity.

  14. Incidence of climate on common frog breeding: Long-term and short-term changes

    Science.gov (United States)

    Neveu, André

    2009-09-01

    In Brittany (northwest France), the climate is showing a trend toward warming. This change is increasingly suspected to have a role in driving amphibian decline, but it is very difficult to determine at what level the climate affects the future of species. Recently, some studies have detected some direct effects on breeding phenology and indirect effects on energy allocation. The present study explores some of these effects on the common frog ( Rana temporaria) from 1984 to 2007. The results show two trends: a long-term change in breeding activities and a short-term influence due to the 2003 climatic anomaly. For the period of study, the start of egg-laying shows a precocity that was correlated with thermal conditions during the preceding 40 days as well as milder springs during the previous year. This degree of precocity is currently the highest found in Europe (+26.6 days). As a result of the 2003 heat wave, the clutch mean fecundity in 2004 was smaller than for other years, the fecundity rates were reduced and abortions were numerous (unlike other years). Moreover, young females were the smallest observed in recent years and some females seemed to exhibit a trade-off between fecundity and growth. Before or after egg-laying, female body condition and mean weight of mature ovules were both lower. The year 2005 appears as a transition period before the recovery in 2006-2007. The results show that climate warming endangers the vital rates of the common frog, while the 2003 climatic events seem more detrimental than the long-term warming trend.

  15. Evaluation of optimal dual axis concentrated photovoltaic thermal system with active ventilation using Frog Leap algorithm

    International Nuclear Information System (INIS)

    Gholami, H.; Sarwat, A.I.; Hosseinian, H.; Khalilnejad, A.

    2015-01-01

    Highlights: • Electro-thermal performance of open-loop controlled dual axis CPVT is investigated. • For using the absorbed heat, active ventilation with a heat storage tank is used. • Economic optimization of the system is performed, using Frog Leap algorithm. • Detailed model of all sections is simulated with their characteristics evaluation. • Triple-junction photovoltaic cells, which are the most recent technology, are used. - Abstract: In this study, design and optimization of a concentrated photovoltaic thermal (CPVT) system considering electrical, mechanical, and economical aspects is investigated. For this purpose, each section of the system is simulated in MATLAB, in detail. Triple-junction photovoltaic cells, which are the most recent technology, are used in this study. They are more efficient in comparison to conventional photovoltaic cells. Unlike ordinary procedures, in this work active ventilation is used for absorbing the thermal power of radiation, using heat storage tanks, which not only results in increasing the electrical efficiency of the system through decreasing the temperature, but also leads to storing and managing produced thermal energy and increasing the total efficiency of the system up to 85 percent. The operation of the CPVT system is investigated for total hours of the year, considering the needed thermal load, meteorological conditions, and hourly radiation of Khuznin, a city in Qazvin province, Iran. Finally, the collector used for this system is optimized economically, using frog leap algorithm, which resulted in the cost of 13.4 $/m"2 for a collector with the optimal distance between tubes of 6.34 cm.

  16. Is the red spotted green frog Hypsiboas punctatus (Anura: Hylidae) selecting its preys? The importance of prey availability.

    Science.gov (United States)

    López, Javier A; Scarabotti, Pablo A; Medrano, María C; Ghirardi, Romina

    2009-09-01

    The study of the feeding ecology of amphibians is an old issue in herpetology. Notwithstanding, the lack of food resources data in many studies of amphibians feeding has lead to partial understanding of frog feeding strategies. In this study we evaluate the trophic selectivity of a red spotted green frog (Hypsiboas punctatus) population from a Middle Paraná River floodplain pond in Argentina, and discuss the importance of prey availability data when interpreting results from diet analysis. We analyzed the gut contents of 47 H. punctatus adults and compared frog's diet with the environmental food resources. Prey availability was estimated by systematically seep-netting the microhabitat where anurans were localized foraging. We identified 33 taxonomic categories from gastrointestinal contents. Numerically, the most important prey categories were dipterans, followed by hemipterans, homopterans and coleopterans. The diet similarity between males and females was high and no statistical differences in diet composition were found. The most abundant food resources in the environment were dipterans, coleopterans, homopterans and collembolans. In order to assess whether frogs were selecting their preys, we calculated Pianka's niche overlap index and Jacobs' electivity index comparing gut contents to prey availability data. Trophic niche overlap was medium but significantly higher than expected by chance. The electivity index indicated that H. punctatus foraged dipterans slightly above their environmental abundance. Among the secondary preys, hemipterans were foraged selectively, homopterans were consumed in the same proportion to their occurrence in the environment, coleopterans were foraged quite under their availability and collembolans were practically ignored by frogs. Without food resources data, H. punctatus could be classified as a specialist feeder, but dipterans also were quite abundant in the environment. Our results show that H. punctatus fit better as a

  17. Frog secretions and hunting magic in the upper Amazon: identification of a peptide that interacts with an adenosine receptor.

    Science.gov (United States)

    Daly, J W; Caceres, J; Moni, R W; Gusovsky, F; Moos, M; Seamon, K B; Milton, K; Myers, C W

    1992-11-15

    A frog used for "hunting magic" by several groups of Panoan-speaking Indians in the borderline between Brazil and Peru is identified as Phyllomedusa bicolor. This frog's skin secretion, which the Indians introduce into the body through fresh burns, is rich in peptides. These include vasoactive peptides, opioid peptides, and a peptide that we have named adenoregulin, with the sequence GLWSKIKEVGKEAAKAAAKAAGKAALGAVSEAV as determined from mass spectrometry and Edman degradation. The natural peptide may contain a D amino acid residue, since it is not identical in chromatographic properties to the synthetic peptide. Adenoregulin enhances binding of agonists to A1 adenosine receptors; it is accompanied in the skin secretion by peptides that inhibit binding. The vasoactive peptide sauvagine, the opioid peptides, and adenoregulin and related peptides affect behavior in mice and presumably contribute to the behavioral sequelae observed in humans.

  18. Hatching success in salamanders and chorus frogs at two sites in Colorado, USA: Effects of acidic deposition and climate

    Science.gov (United States)

    Muths, E.; Campbell, D.H.; Corn, P.S.

    2003-01-01

    The snowpack in the vicinity of the Mount Zirkel Wilderness Area is among the most acidic in the western United States. We analyzed water chemistry and examined hatching success in tiger salamanders and chorus frogs at ponds there and at nearby Rabbit Ears Pass (Dumont) to determine whether acid deposition affects amphibians or their breeding habitats at these potentially sensitive locations. We found a wide range of acid neutralizing capacity among ponds within sites; the minimum pH recorded during the experiment was 5.4 at one of 12 ponds with all others at pH ??? 5.7. At Dumont, hatching success for chorus frogs was greater in ponds with low acid neutralizing capacity; however, lowest pHs were >5.8. At current levels of acid deposition, weather and pond characteristics are likely more important than acidity in influencing hatching success in amphibian larvae at these sites.

  19. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria)

    OpenAIRE

    Strong, Becky; Halsall, Crispin James; Ferenčík, Martin; Jones, Kevin Christopher; Shore, Richard Francis; Martin, Francis Luke

    2016-01-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpol...

  20. FROG INTESTINAL PERFUSION TO EVALUATE DRUG PERMEABILITY: APPLICATION TO P-gp AND CYP3A4 SUBSTRATES

    Directory of Open Access Journals (Sweden)

    Neelima eYerasi

    2015-07-01

    Full Text Available AbstractTo evaluate the reliability of using in situ frog intestinal perfusion technique for permeability assessment of carrier transported drugs which are also substrates for CYP enzymes. Single Pass Intestinal Perfusion (SPIP studies were performed in frogs of the species Rana tigrina using established method for rats with some modifications after inducing anesthesia. Effective permeability coefficient (Peff of losartan and midazolam was calculated in the presence and absence of inhibitors using the parallel-tube model. Peff of losartan when perfused alone was found to be 0.427 ± 0.27×10-4cm/s and when it was co-perfused with inhibitors, significant change in Peff was observed. Peff of midazolam when perfused alone was found to be 2.03 ± 0.07 × 10-4cm/s and when it was co-perfused with inhibitors, no significant change in Peff was observed. Comparison of Peff calculated in frog with that of other available models and also humans suggested that the Peff values are comparable and reflected well with human intestinal permeability. It is possible to determine the Peff value for compounds which are dual substrates of P-gp and CYP3A4 using in situ frog intestinal perfusion technique. The calculated Peff values correlated well with reported Peff values of probe drugs. comparison of the Peff value of losartan obtained with that of reported human’s Peff and Caco 2 cell data, and comparison of the Peff value of midazolam with that of reported rat’s Peff, we could conclude that SPIP from model can be reliably used in preclinical studies for permeability estimation. This model may represent a valuable alternative to the low speed and high cost of conventional animal models (typically rodents for the assessment of intestinal permeability.

  1. Number of genes controlling a quantitative trait in a hybrid zone of the aposematic frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Vestergaard, Jacob Schack; Twomey, Evan; Larsen, Rasmus

    2015-01-01

    The number of genes controlling mimetic traits has been a topic of much research and discussion. In this paper, we examine a mimetic, dendrobatid frog Ranitomeya imitator, which harbours extensive phenotypic variation with multiple mimetic morphs, not unlike the celebrated Heliconius system...... and apply it to the R. imitator system. We show that probably one or two, or at most three genes, control the mimetic phenotype segregating in a R. imitator hybrid zone identified using image analyses....

  2. Cadmium Contamination and Health Assessment in Frog Microhyla fissipes Living Downstream of Zinc Mining Area in Thailand

    Directory of Open Access Journals (Sweden)

    Jirarach Kitana

    2015-01-01

    Full Text Available In Mae Sot District, Tak Province, Thailand, concerns have been raised over cadmium contamination, potentially due to zinc mining activities. Although there is no report of acute toxicity on animals in this area, the impact of long-term environmental exposure to cadmium on their health are of attention. Water and sediment samples collected from two field sites (low-Cd and high-Cd sites in Mae Sot during 2008 were analyzed by GFAAS. Year round cadmium contamination in water ranged from 0.0015-0.002 mg/L in low-Cd site to 0.0019-0.0023 mg/L in high-Cd site, while higher levels were found in sediment ranged from 0.1013-0.2206 mg/kg in low-Cd site to 2.9260-3.2888 mg/kg in high-Cd site. Microhyla fissipes was collected from each habitat in 2-month interval during wet season. Detectable level of cadmium residue was found only in the frog collected from high-Cd habitat. Gravimetric analysis showed that hepatosomatic indices were significantly higher in high-Cd habitat. Histopathology showed several similar alterations in the liver, however higher number of melanomacrophage center was found in high-Cd habitat. Renosomatic indices and kidney tissue alterations were not significantly different between two sites. Reproductive health in term of gonadosomatic indices (GSI was not significantly different between male frogs from both habitats. But in the females living in high-Cd habitat, significantly lower GSI were observed. The results indicate that exposure to environmentally relevant dose of cadmium may interfere with the frog health. Using the frog as a sentinel species in this study suggests an important implication for overall health of animals/human in this area.

  3. The role of desensititation in decay time of miniature endplate currents in frogs Rana ridibunda and Rana temporaria

    Czech Academy of Sciences Publication Activity Database

    Giniatullin, R. A.; Talantova, M. V.; Vyskočil, František

    2001-01-01

    Roč. 39, č. 3 (2001), s. 287-292 ISSN 0168-0102 R&D Projects: GA AV ČR IAA7011902; GA MŠk VS97099; GA MŠk OK 267 Grant - others:RFBR(RU) 98-04-48044; INTAS(BE) 2000-1147 Institutional research plan: CEZ:AV0Z5011922 Keywords : frog * desensitisation * miniature endplate potential Subject RIV: ED - Physiology Impact factor: 1.770, year: 2001

  4. Cross-tolerance in amphibians: wood frog mortality when exposed to three insecticides with a common mode of action.

    Science.gov (United States)

    Hua, Jessica; Cothran, Rickey; Stoler, Aaron; Relyea, Rick

    2013-04-01

    Insecticide tolerance and cross-tolerance in nontarget organisms is often overlooked despite its potential to buffer natural systems from anthropogenic influence. We exposed wood frog tadpoles from 15 populations to three acetylcholine esterase-inhibiting insecticides and found widespread variation in insecticide tolerance and evidence for cross-tolerance to these insecticides. Our results demonstrate that amphibian populations with tolerance to one pesticide may be tolerant to many other pesticides. Copyright © 2013 SETAC.

  5. Efficient induction of spawning of Northern leopard frogs (Lithobates pipiens) during and outside the natural breeding season

    OpenAIRE

    Trudeau, Vance L; Schueler, Frederick W; Navarro-Martin, Laia; Hamilton, Christine K; Bulaeva, Elizabeth; Bennett, Amanda; Fletcher, William; Taylor, Lisa

    2013-01-01

    Background Amphibian declines are now recognized globally. It is also well known that many anurans do not reproduce easily in captivity, especially when held over long periods, or if they require hibernation before breeding. A simple method to induce spawning and subsequent development of large numbers of healthy tadpoles is therefore required to meet research and conservation goals. Methods The method is based on simultaneous injection of both female and male leopard frogs, Lithobates pipien...

  6. An enigmatic frog of the genus Atelopus (Family Bufonidae) from Parque Nacional Chirripó, Cordillera de Talamanca, Costa Rica

    OpenAIRE

    Jay M Savage; Federico Bolaños

    2009-01-01

    A distinctive new species of Atelopus is described from Parque Nacional Chirripó Grande, Cordillera de Talamanca (3 400-3 500 m). It closely resembles populations of the Atelopus ignescens complex from the Andes of northern Ecuador and southern Colombia. it differs most significantly from these frogs in the pattern of spiculae and coni development on the throat, chest, hands and feet. The Costa Rican species appears to be an outlier of the complex inexplicably separated geographically from it...

  7. Dopaminergic modulation of mitral cell activity in the frog olfactory bulb: a combined radioligand binding-electrophysiological study

    International Nuclear Information System (INIS)

    Duchamp, A.; Moyse, E.; Delaleu, J.-C.; Coronas, V.; Duchamp-Viret, P.

    1997-01-01

    Dopamine content in the amphibian olfactory bulb is supplied by interneurons scattered among mitral cells in the external plexiform/mitral cell layer. In mammals, dopamine has been found to be involved in various aspects of bulbar information processing by influencing mitral cell odour responsiveness. Dopamine action in the bulb depends directly on the localization of its receptor targets, found to be mainly of the D 2 type in mammals. The present study assessed, in the frog, both the anatomical localization of D 2 -like, radioligand-labelled receptors of dopamine and the in vivo action of dopamine on unitary mitral cell activity in response to odours delivered over a wide range of concentrations. The [ 125 I]iodosulpride-labelled D 2 binding sites were visualized on frozen sagittal sections of frog brains by film radioautography. The sites were found to be restricted to the external plexiform/mitral cell layer; other layers of the olfactory bulb were devoid of specific labelling. Electrophysiological recordings of mitral unit activity revealed that dopamine or its agonist apomorphine induced a drastic reduction of spontaneous firing rate of mitral cells in most cases without altering odour intensity coding properties of these cells. Moreover, pre-treatment with the D 2 antagonist eticlopride blocked the dopamine-induced reduction of mitral cell spontaneous activity.In the frog olfactory bulb, both anatomical localization of D 2 -like receptors and functional data on dopamine involvement in information processing differ from those reported in mammals. This suggests a phylogenetic evolution of dopamine action in the olfactory bulb. In the frog, anatomical data perfectly corroborate electrophysiological results, together strongly suggesting a direct action of dopamine on mitral cells. In a physiologically operating system, such an action would result in a global improvement of signal-to-noise ratio. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights

  8. Reversal to air-driven sound production revealed by a molecular phylogeny of tongueless frogs, family Pipidae

    Directory of Open Access Journals (Sweden)

    Glaw Frank

    2011-04-01

    Full Text Available Abstract Background Evolutionary novelties often appear by conferring completely new functions to pre-existing structures or by innovating the mechanism through which a particular function is performed. Sound production plays a central role in the behavior of frogs, which use their calls to delimit territories and attract mates. Therefore, frogs have evolved complex vocal structures capable of producing a wide variety of advertising sounds. It is generally acknowledged that most frogs call by moving an air column from the lungs through the glottis with the remarkable exception of the family Pipidae, whose members share a highly specialized sound production mechanism independent of air movement. Results Here, we performed behavioral observations in the poorly known African pipid genus Pseudhymenochirus and document that the sound production in this aquatic frog is almost certainly air-driven. However, morphological comparisons revealed an indisputable pipid nature of Pseudhymenochirus larynx. To place this paradoxical pattern into an evolutionary framework, we reconstructed robust molecular phylogenies of pipids based on complete mitochondrial genomes and nine nuclear protein-coding genes that coincided in placing Pseudhymenochirus nested among other pipids. Conclusions We conclude that although Pseudhymenochirus probably has evolved a reversal to the ancestral non-pipid condition of air-driven sound production, the mechanism through which it occurs is an evolutionary innovation based on the derived larynx of pipids. This strengthens the idea that evolutionary solutions to functional problems often emerge based on previous structures, and for this reason, innovations largely depend on possibilities and constraints predefined by the particular history of each lineage.

  9. Neural activity patterns in response to interspecific and intraspecific variation in mating calls in the túngara frog.

    Directory of Open Access Journals (Sweden)

    Mukta Chakraborty

    2010-09-01

    Full Text Available During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus can produce single note calls (whines and multi-note calls (whine-chucks. While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice.To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of egr-1. We predicted that egr-1 responses to conspecific calls would identify brain regions that are potentially important for species recognition and that at least some of those brain regions would vary in their egr-1 responses to mating calls that vary in attractiveness. We measured egr-1 in the auditory brainstem and its forebrain targets and found that conspecific whine-chucks elicited greater egr-1 expression than heterospecific whines in all but three regions. We found no evidence that preferred whine-chuck calls elicited greater egr-1 expression than conspecific whines in any of eleven brain regions examined, in contrast to predictions that mating preferences in túngara frogs emerge from greater responses in the auditory system.Although selectivity for species-specific signals is apparent throughout the túngara frog brain, further studies are necessary to elucidate how neural activity patterns vary with the attractiveness of conspecific mating calls.

  10. S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa.

    Science.gov (United States)

    Picariello, Orfeo; Feliciello, Isidoro; Chinali, Gianni

    2016-02-01

    S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species. We characterized S1 satellite DNA from the Anatolian brown frogs Rana macrocnemis, R. camerani, and R. holtzi in order to define their taxonomic rank and the structure of this satellite in this frog lineage. Southern blots of genomic DNA digested with KpnI, EcoRV, NdeI, NheI, or StuI produced the same pattern of satellite DNA bands. Moreover, quantitative dot blots showed that this satellite DNA accounts for 0.1 % of the genome in all taxa. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size (476 bp), the same most common sequence (MCS) and the same overall variability in all three taxa, and also in R. macrocnemis tavasensis. The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the 494-bp S1a repeat from European frogs. The S1a MCS has three variable positions (sequence WWTK in positions 183-186), due to the presence of two repeat subpopulations with motifs AATG and WWTT in all taxa. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

  11. Freshwater paths across the ocean: molecular phylogeny of the frog Ptychadena newtoni gives insights into amphibian colonization of oceanic islands

    OpenAIRE

    Measey, John G.; Vences, M.; Drewes, R. C.; Chiari, Y.; Melo, M.; Bourlès, Bernard

    2007-01-01

    Aim Amphibians are a model group for studies of the biogeographical origins of salt-intolerant taxa on oceanic islands. We used the Gulf of Guinea islands to explore the biogeographical origins of island endemism of one species of frog, and used this to gain insights into potential colonization mechanisms. Location Sao Tome and Principe, two of the four major islands in the Gulf of Guinea, West Africa, are truly oceanic and have an exceptionally high biodiversity. Methods Mitochondrial DNA is...

  12. When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

    Directory of Open Access Journals (Sweden)

    Niall Crawford

    2016-12-01

    Full Text Available Tree frogs need to adhere to surfaces of various roughnesses in their natural habitats; these include bark, leaves and rocks. Rough surfaces can alter the effectiveness of their toe pads, due to factors such as a change of real contact area and abrasion of the pad epithelium. Here, we tested the effect of surface roughness on the attachment abilities of the tree frog Litoria caerulea. This was done by testing shear and adhesive forces on artificial surfaces with controlled roughness, both on single toe pads and whole animal scales. It was shown that frogs can stick 2–3 times better on small scale roughnesses (3–6 µm asperities, producing higher adhesive and frictional forces, but relatively poorly on the larger scale roughnesses tested (58.5–562.5 µm asperities. Our experiments suggested that, on such surfaces, the pads secrete insufficient fluid to fill the space under the pad, leaving air pockets that would significantly reduce the Laplace pressure component of capillarity. Therefore, we measured how well the adhesive toe pad would conform to spherical asperities of known sizes using interference reflection microscopy. Based on experiments where the conformation of the pad to individual asperities was examined microscopically, our calculations indicate that the pad epithelium has a low elastic modulus, making it highly deformable.

  13. Influence of heat treatment on microstructure and properties of bainitic cast steel used for frogs in railway crossovers

    Directory of Open Access Journals (Sweden)

    E. Tasak

    2010-01-01

    Full Text Available This work deals with influence of heat treatment on microstructure and properties of sample cast assigned as a material used for frogs in railway crossover. Materials used in railway industry for frogs (manganese cast steel and forged pearlitic steel do not fulfil strict conditions of exploitation of railway. One of the solutions is using cast steel with bainitic or bainite-martensite microstructure, what allows to gain high resistance properties (Rm = 1400 MPa, Rp0,2 = 900 MPa, hardness to 400 HBW. The cooling rates of rail type UIC60 shows that it is possible to reach the bainitic microstructure in cast of frog. The microstructure of lower banite should have an advantageous influence on cracking resistance. In order to set the parameters of heat treatment, the critical temperatures were determined by dilatometric methods determined. This heat treatment consisted of normalizing that prepared it to the farther process of resistance welding. Moreover, the CCT diagram of proposed bainitic cast steel was prepared. The exams were done that can be used to evaluate the influence of heat treatment on microstructure and properties of the sample cast.

  14. Habitat connectivity and resident shared predators determine the impact of invasive bullfrogs on native frogs in farm ponds.

    Science.gov (United States)

    Atobe, Takashi; Osada, Yutaka; Takeda, Hayato; Kuroe, Misako; Miyashita, Tadashi

    2014-07-07

    Habitat connectivity is considered to have an important role on the persistence of populations in the face of habitat fragmentation, in particular, for species with conservation concern. However, it can also impose indirect negative effects on native species through the spread of invasive species. Here, we investigated direct and indirect effects of habitat connectivity on populations of invasive bullfrogs and native wrinkled frogs and how these effects are modified by the presence of common carp, a resident shared predator, in a farm pond system in Japan. The distribution pattern analysis using a hierarchical Bayesian modelling indicated that bullfrogs had negative effects on wrinkled frogs, and that these negative effects were enhanced with increasing habitat connectivity owing to the metapopulation structure of bullfrogs. The analysis also suggested that common carp mitigated these impacts, presumably owing to a top-down trophic cascade through preferential predation on bullfrog tadpoles. These presumed interspecific interactions were supported by evidence from laboratory experiments, i.e. predation by carp was more intense on bullfrog tadpoles than on wrinkled frog tadpoles owing to the difference in refuge use. Our results indicate that metacommunity perspectives could provide useful insights for establishing effective management strategies of invasive species living in patchy habitats. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  15. The evolution of reproductive diversity in Afrobatrachia: A phylogenetic comparative analysis of an extensive radiation of African frogs

    Science.gov (United States)

    Portik, Daniel M.; Blackburn, David C.

    2016-01-01

    The reproductive modes of anurans (frogs and toads) are the most diverse of terrestrial vertebrates, and a major challenge is identifying selective factors that promote the evolution or retention of reproductive modes across clades. Terrestrialized anuran breeding strategies have evolved repeatedly from the plesiomorphic fully aquatic reproductive mode, a process thought to occur through intermediate reproductive stages. Several selective forces have been proposed for the evolution of terrestrialized reproductive traits, but factors such as water systems and co‐evolution with ecomorphologies have not been investigated. We examined these topics in a comparative phylogenetic framework using Afrobatrachian frogs, an ecologically and reproductively diverse clade representing more than half of the total frog diversity found in Africa (∼400 species). We infer direct development has evolved twice independently from terrestrialized reproductive modes involving subterranean or terrestrial oviposition, supporting evolution through intermediate stages. We also detect associations between specific ecomorphologies and oviposition sites, and demonstrate arboreal species exhibit an overall shift toward using lentic water systems for breeding. These results indicate that changes in microhabitat use associated with ecomorphology, which allow access to novel sites for reproductive behavior, oviposition, or larval development, may also promote reproductive mode diversity in anurans. PMID:27402182

  16. Evidence of niche shift and invasion potential of Lithobates catesbeianus in the habitat of Mexican endemic frogs.

    Directory of Open Access Journals (Sweden)

    Jorge Luis Becerra López

    Full Text Available Invasive alien species are one of most severe threats to biodiversity and natural resources. These biological invasions have been studied from the niche conservatism and niche shifts perspective. Niche differentiation may result from changes in fundamental niche or realized niche or both; in biological invasions, niche differences between native and non-native ranges can appear through niche expansion, niche unfilling and niche stability. The American bullfrog Lithobates catesbeianus is an invasive species that can have negative impacts on native amphibian populations. This research examines the climate niche shifts of this frog, its potential range of expansion in Mexico and the risk of invasion by bullfrog in the habitats of 82 frog species endemic to Mexico, that based on their climatic niche similarity were divided in four ecological groups. The results indicate that species in two ecological groups were the most vulnerable to invasion by bullfrog. However, the climate niche shifts of L. catesbeianus may allow it to adapt to new environmental conditions, so species from the two remaining groups cannot be dismissed as not vulnerable. This information is valuable for decision making in prioritizing areas for conservation of Mexican endemic frogs.

  17. Effects of prey type on specific dynamic action, growth, and mass conversion efficiencies in the horned frog, Ceratophrys cranwelli.

    Science.gov (United States)

    Grayson, Kristine L; Cook, Leslie W; Todd, M Jason; Pierce, D; Hopkins, William A; Gatten, Robert E; Dorcas, Michael E

    2005-07-01

    To be most energetically profitable, predators should ingest prey with the maximal nutritional benefit while minimizing the cost of processing. Therefore, when determining the quality of prey items, both the cost of processing and nutritional content must be considered. Specific dynamic action (SDA), the increase in metabolic rate associated with feeding in animals, is a significant processing cost that represents the total cost of digestion and assimilation of nutrients from prey. We examined the effects of an invertebrate diet (earthworms) and a vertebrate diet (newborn mice) on mass conversion efficiencies, growth, and SDA in the Chacoan horned frog, Ceratophrys cranwelli. We found the earthworm diet to be significantly lower in lipid, protein, and energy content when compared to the diet of newborn mice. Growth and mass conversion efficiencies were significantly higher in frogs fed newborn mice. However, mean SDA did not differ between frogs fed the two diets, a finding that contradicts many studies that indicate SDA increases with the protein content of the meal. Together, our results indicate that future studies evaluating the effect of meal type on bioenergetics of herpetofauna are warranted and may provide significant insight into the underlying factors driving SDA.

  18. Diversification of rhacophorid frogs provides evidence for accelerated faunal exchange between India and Eurasia during the Oligocene.

    Science.gov (United States)

    Li, Jia-Tang; Li, Yang; Klaus, Sebastian; Rao, Ding-Qi; Hillis, David M; Zhang, Ya-Ping

    2013-02-26

    The accretion of the Indian subcontinent to Eurasia triggered a massive faunal and floral exchange, with Gondwanan taxa entering into Asia and vice versa. The traditional view on the Indian-Asian collision assumes contact of the continental plates during the Early Eocene. Many biogeographic studies rely on this assumption. However, the exact mode and timing of this geological event is still under debate. Here we address, based on an extensive phylogenetic analysis of rhacophorid tree frogs, if there was already a Paleogene biogeographic link between Southeast Asia and India; in which direction faunal exchange occurred between India and Eurasia within the Rhacophoridae; and if the timing of the faunal exchange correlates with one of the recently suggested geological models. Rhacophorid tree frogs showed an early dispersal from India to Asia between 46 and 57 Ma, as reconstructed from the fossil record. During the Middle Eocene, however, faunal exchange ceased, followed by increase of rhacophorid dispersal events between Asia and the Indian subcontinent during the Oligocene that continued until the Middle Miocene. This corroborates recent geological models that argue for a much later final collision between the continental plates. We predict that the Oligocene faunal exchange between the Indian subcontinent and Asia, as shown here for rhacophorid frogs, also applies for other nonvolant organisms with an Indian-Asian distribution, and suggest that previous studies that deal with this faunal interchange should be carefully reinvestigated.

  19. Determining the influence of muscle operating length on muscle performance during frog swimming using a bio-robotic model

    International Nuclear Information System (INIS)

    Clemente, Christofer J; Richards, Christopher

    2012-01-01

    Frogs are capable of impressive feats of jumping and swimming. Recent work has shown that anuran hind limb muscles can operate at lengths longer than the ‘optimal length’. To address the implications of muscle operating length on muscle power output and swimming mechanics, we built a robotic frog hind limb model based upon Xenopus laevis. The model simulated the force–length and force–velocity properties of vertebrate muscle, within the skeletal environment. We tested three muscle starting lengths, representing long, optimal and short starting lengths. Increasing starting length increased maximum muscle power output by 27% from 98.1 W kg −1 when muscle begins shortening from the optimal length, to 125.1 W kg −1 when the muscle begins at longer initial lengths. Therefore, longer starting lengths generated greater hydrodynamic force for extended durations, enabling faster swimming speeds of the robotic frog. These swimming speeds increased from 0.15 m s −1 at short initial muscle lengths, to 0.39 m s −1 for the longest initial lengths. Longer starting lengths were able to increase power as the muscle's force–length curve was better synchronized with the muscle's activation profile. We further dissected the underlying components of muscle force, separating force–length versus force–velocity effects, showing a transition from force–length limitations to force–velocity limitations as starting length increased. (paper)

  20. Post-evaluation of the neurophaties treatment post-trauma with therapeutic laser. Model in sciatic nerve of frog

    Science.gov (United States)

    Escobar, Antonio S.; Ocampo, Arcelia F. M.; Hernández, María G. H.; Jasso, José L. C.; Lira, Maricela O. F.; Flores, Mariana A.; Balderrama, Vicente L.

    2010-05-01

    The purpose of this study was to evaluate the compound nerve action potential amplitude and latency measured to determine the degree of myelination and the number of fibers stimulated in a model of stimulated frog sciatic nerve laser at 810 nm as perioperative treatment after injury. It used 30 bullfrogs (Rana catesbeiana) to obtain 60 sciatic nerves forming four groups, groups 1 and 2 worked with nerves in vitro, were dissected in humid chambers for placing isolated organ, was recorded on compound nerve action potential, the second group laser was applied at 24, 48, 72, 96 and 120 hours and at the same time were placed in 10% formalin. Groups 3 and 4 are worked in vivo localizing the nerve and causing damage through compression, occurred over the compound nerve action potential to assess the degree of myelination and the number of fibers stimulated, the group 4 was applied to 810 nm laser (500 Hz, 10 J, 200 mW) after injury, after 48 hours, three frogs were sacrificed by introducing the nerves in 10% formalin. The latency recorded by stimulating the sciatic nerve of frog to 0.5 mA and 100 ms in groups 1 and 2 show significant differences (p000), as to the extent, if any statistically significant difference. (pparesthesia (post-traumatic neuropathy).

  1. Post-evaluation of the neurophaties treatment post-trauma with therapeutic laser. Model in sciatic nerve of frog

    International Nuclear Information System (INIS)

    Escobar, Antonio S.; Ocampo, Arcelia F. M.; Hernandez, Maria G. H.; Jasso, Jose L. C.; Lira, Maricela O. F.; Flores, Mariana A.; Balderrama, Vicente L.

    2010-01-01

    The purpose of this study was to evaluate the compound nerve action potential amplitude and latency measured to determine the degree of myelination and the number of fibers stimulated in a model of stimulated frog sciatic nerve laser at 810 nm as perioperative treatment after injury. It used 30 bullfrogs (Rana catesbeiana) to obtain 60 sciatic nerves forming four groups, groups 1 and 2 worked with nerves in vitro, were dissected in humid chambers for placing isolated organ, was recorded on compound nerve action potential, the second group laser was applied at 24, 48, 72, 96 and 120 hours and at the same time were placed in 10% formalin. Groups 3 and 4 are worked in vivo localizing the nerve and causing damage through compression, occurred over the compound nerve action potential to assess the degree of myelination and the number of fibers stimulated, the group 4 was applied to 810 nm laser (500 Hz, 10 J, 200 mW) after injury, after 48 hours, three frogs were sacrificed by introducing the nerves in 10% formalin. The latency recorded by stimulating the sciatic nerve of frog to 0.5 mA and 100 ms in groups 1 and 2 show significant differences (p 000), as to the extent, if any statistically significant difference. (p<0.001 and p<0.000). The laser produces a favorable response in the treatment of paresthesia (post-traumatic neuropathy).

  2. Water balance of field-excavated aestivating Australian desert frogs, the cocoon-forming Neobatrachus aquilonius and the non-cocooning Notaden nichollsi (Amphibia: Myobatrachidae).

    Science.gov (United States)

    Cartledge, Victoria A; Withers, Philip C; McMaster, Kellie A; Thompson, Graham G; Bradshaw, S Don

    2006-09-01

    Burrowed aestivating frogs of the cocoon-forming species Neobatrachus aquilonius and the non-cocooning species Notaden nichollsi were excavated in the Gibson Desert of central Australia. Their hydration state (osmotic pressure of the plasma and urine) was compared to the moisture content and water potential of the surrounding soil. The non-cocooning N. nichollsi was consistently found in sand dunes. While this sand had favourable water potential properties for buried frogs, the considerable spatial and temporal variation in sand moisture meant that frogs were not always in positive water balance with respect to the surrounding soil. The cocoon-forming N. aquilonius was excavated from two distinct habitat types, a claypan in which frogs had a well-formed cocoon and a dune swale where frogs did not have a cocoon. Cocoons of excavated frogs ranged in thickness from 19.4 microm to 55.61 microm and consisted of 81-229 layers. Cocooned claypan N. aquilonius were nearing exhaustion of their bladder water reserves and had a urine osmolality approaching that of the plasma. By contrast, non-cocooned N. aquilonius from the dune swale were fully hydrated, although soil moisture levels were not as high as calculated to be necessary to maintain water balance. Both species had similar plasma arginine vasotocin (AVT) concentrations ranging from 9.4 to 164 pg ml(-1), except for one cocooned N. aquilonius with a higher concentration of 394 pg ml(-1). For both species, AVT showed no relationship with plasma osmolality over the lower range of plasma osmolalities but was appreciably increased at the highest osmolality recorded. This study provides the first evidence that cocoon formation following burrowing is not obligatory in species that are capable of doing so, but that cocoon formation occurs when soil water conditions are more desiccating than for non-cocooned frogs.

  3. INTRAOCULAR PRESSURE AND EXAMINATION FINDINGS IN THREE SPECIES OF CENTRAL AND SOUTH AMERICAN TREE FROGS (CRUZIOHYLA CRASPEDOPUS, CRUZIOHYLA CALCARIFER, AND ANOTHECA SPINOSA).

    Science.gov (United States)

    Lewin, Andrew C; Hausmann, Jennifer C; Miller, Paul E

    2017-09-01

    The purpose of this prospective study was to describe intraocular pressure (IOP) and examination findings in three tree frog species (Cruziohyla craspedopus [fringe leaf frog], Cruziohyla calcarifer [splendid leaf frog], and Anotheca spinosa [spiny-headed or coronated tree frog]). Thirty-one C. craspedopus, four C. calcarifer, and five A. spinosa were weighed, sexed based on phenotype where possible, and examined using slit-lamp biomicroscopy and indirect ophthalmoscopy. IOP was measured using the TonoVet and TonoLab rebound tonometers while the frogs were held two ways (unrestrained, then restrained). Statistical differences were determined using one-way analysis of variance (ANOVA) and t-tests. Mean ± SD IOP (TonoVet and TonoLab, respectively) was 15.1 ± 2.5 mmHg and 15.6 ± 4.1 mmHg in C. craspedopus; 14.8 ± 1.5 mmHg and 18.8 ± 3.1 mmHg in C. calcarifer; and 9.1 ± 2.1 mmHg and 10.8 ± 1.4 mmHg in A. spinosa. There was no significant difference in IOP in C. craspedopus by eye (Right vs Left), tonometer, or restraint method. IOP in female C. craspedopus was 1-3 mm Hg higher than in males with both devices (P Cruziohyla genus frogs and A. spinosa for the TonoVet (P < 0.05). There was no difference in IOP measurements between the TonoVet and TonoLab in C. craspedopus. IOP varied by gender in C. craspedopus and between species, but not by tonometer. Ocular abnormalities were minimal in this group of captive bred frogs.

  4. Testing Convergence Versus History: Convergence Dominates Phenotypic Evolution for over 150 Million Years in Frogs.

    Science.gov (United States)

    Moen, Daniel S; Morlon, Hélène; Wiens, John J

    2016-01-01

    Striking evolutionary convergence can lead to similar sets of species in different locations, such as in cichlid fishes and Anolis lizards, and suggests that evolution can be repeatable and predictable across clades. Yet, most examples of convergence involve relatively small temporal and/or spatial scales. Some authors have speculated that at larger scales (e.g., across continents), differing evolutionary histories will prevent convergence. However, few studies have compared the contrasting roles of convergence and history, and none have done so at large scales. Here we develop a two-part approach to test the scale over which convergence can occur, comparing the relative importance of convergence and history in macroevolution using phylogenetic models of adaptive evolution. We apply this approach to data from morphology, ecology, and phylogeny from 167 species of anuran amphibians (frogs) from 10 local sites across the world, spanning ~160 myr of evolution. Mapping ecology on the phylogeny revealed that similar microhabitat specialists (e.g., aquatic, arboreal) have evolved repeatedly across clades and regions, producing many evolutionary replicates for testing for morphological convergence. By comparing morphological optima for clades and microhabitat types (our first test), we find that convergence associated with microhabitat use dominates frog morphological evolution, producing recurrent ecomorphs that together encompass all sampled species in each community in each region. However, our second test, which examines whether and how much species differ from their inferred optima, shows that convergence is incomplete: that is, phenotypes of most species are still somewhat distant from the estimated optimum for each microhabitat, seemingly because of insufficient time for more complete adaptation (an effect of history). Yet, these effects of history are related to past ecologies, and not clade membership. Overall, our study elucidates the dominant drivers of

  5. Cryptic diversity and deep divergence in an upper Amazonian leaflitter frog, Eleutherodactylus ockendeni

    Directory of Open Access Journals (Sweden)

    Dávila José A

    2007-12-01

    Full Text Available Abstract Background The forests of the upper Amazon basin harbour some of the world's highest anuran species richness, but to date we have only the sparsest understanding of the distribution of genetic diversity within and among species in this region. To quantify region-wide genealogical patterns and to test for the presence of deep intraspecific divergences that have been documented in some other neotropical anurans, we developed a molecular phylogeny of the wide-spread terrestrial leaflitter frog Eleutherodactylus ockendeni (Leptodactylidae from 13 localities throughout its range in Ecuador using data from two mitochondrial genes (16S and cyt b; 1246 base pairs. We examined the relation between divergence of mtDNA and the nuclear genome, as sampled by five species-specific microsatellite loci, to evaluate indirectly whether lineages are reproductively isolated where they co-occur. Our extensive phylogeographic survey thus assesses the spatial distribution of E. ockendeni genetic diversity across eastern Ecuador. Results We identified three distinct and well-supported clades within the Ecuadorean range of E. ockendeni: an uplands clade spanning north to south, a northeastern and central lowlands clade, and a central and southeastern clade, which is basal. Clades are separated by 12% to 15% net corrected p-distance for cytochrome b, with comparatively low sequence divergence within clades. Clades marginally overlap in some geographic areas (e.g., Napo River basin but are reproductively isolated, evidenced by diagnostic differences in microsatellite PCR amplification profiles or DNA repeat number and coalescent analyses (in MDIV best modelled without migration. Using Bayesian (BEAST and net phylogenetic estimates, the Southeastern Clade diverged from the Upland/Lowland clades in the mid-Miocene or late Oligocene. Lowland and Upland clades speciated more recently, in the early or late Miocene. Conclusion Our findings uncover previously

  6. Variation in genotoxic stress tolerance among frog populations exposed to UV and pollutant gradients

    International Nuclear Information System (INIS)

    Marquis, Olivier; Miaud, Claude; Ficetola, Gentile Francesco; Bocher, Aurore; Mouchet, Florence; Guittonneau, Sylvie; Devaux, Alain

    2009-01-01

    Populations of widely distributed species can be subjected to unequal selection pressures, producing differences in rates of local adaptation. We report a laboratory experiment testing tolerance variation to UV-B and polycyclic aromatic hydrocarbons (PAHs) among common frog (Rana temporaria) populations according to their natural exposure level in the field. Studied populations were naturally distributed along two gradients, i.e. UV-B radiation with altitude and level of contamination by PAHs with the distance to emitting sources (road traffic). Tadpoles from eight populations were subjected to (1) no or high level of artificial UV-B; (2) four concentrations of benzo[a]pyrene (BaP) (0, 50, 250, 500 μg L -1 ); (3) simultaneously to UV-B and BaP. Since both stressors are genotoxic, the number of micronucleated erythrocytes (MNE) in circulating red blood cells was used as a bioindicator of tadpole sensitivity. High-altitude populations appear to be locally adapted to better resist UV-B genotoxicity, as they showed the lowest MNE numbers. Conversely, no correlation was observed between levels of PAH contamination in the field and tadpole tolerance to BaP in the laboratory, indicating the absence of local adaptation for BaP tolerance in these populations. Nevertheless, the decrease of MNE formation due to BaP exposure with altitude suggests that high-altitude populations were intrinsically more resistant to BaP genotoxicity. We propose the hypothesis of a co-tolerance between UV-B and BaP in high-altitude common frog populations: local adaptation to prevent and/or repair DNA damage induced by UV-B could also protect these highland populations against DNA damage induced by BaP. The results of this study highlight the role of local adaptation along pollutant gradients leading to tolerance variation, which implies that is it necessary to take into account the history of exposure of each population and the existence of co-tolerance that can hide toxic effects of a new

  7. Variation in genotoxic stress tolerance among frog populations exposed to UV and pollutant gradients

    Energy Technology Data Exchange (ETDEWEB)

    Marquis, Olivier [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Miaud, Claude, E-mail: claude.miaud@univ-savoie.fr [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Ficetola, Gentile Francesco [Laboratoire d' Ecologie Alpine, UMR CNRS 5553, Universite de Savoie, Technolac, Le Bourget du Lac (France); Department of Biology, Universita degli Studi di Milano, Milan (Italy); Bocher, Aurore [Laboratoire de Chimie Moleculaire et Environnement, Universite de Savoie, Le Bourget du Lac (France); Mouchet, Florence [Laboratoire d' Ecologie Fonctionnelle, UMR CNRS-UPS-INPT 5245, Institut National Polytechnique-ENSAT, Auzeville-Tolosane (France); Guittonneau, Sylvie [Laboratoire de Chimie Moleculaire et Environnement, Universite de Savoie, Le Bourget du Lac (France); Devaux, Alain [Laboratoire des Sciences de l' Environnement, Ecole Nationale des Travaux Publics de l' Etat, INRA-EFPA, Vaulx-en-Velin (France)

    2009-11-08

    Populations of widely distributed species can be subjected to unequal selection pressures, producing differences in rates of local adaptation. We report a laboratory experiment testing tolerance variation to UV-B and polycyclic aromatic hydrocarbons (PAHs) among common frog (Rana temporaria) populations according to their natural exposure level in the field. Studied populations were naturally distributed along two gradients, i.e. UV-B radiation with altitude and level of contamination by PAHs with the distance to emitting sources (road traffic). Tadpoles from eight populations were subjected to (1) no or high level of artificial UV-B; (2) four concentrations of benzo[a]pyrene (BaP) (0, 50, 250, 500 {mu}g L{sup -1}); (3) simultaneously to UV-B and BaP. Since both stressors are genotoxic, the number of micronucleated erythrocytes (MNE) in circulating red blood cells was used as a bioindicator of tadpole sensitivity. High-altitude populations appear to be locally adapted to better resist UV-B genotoxicity, as they showed the lowest MNE numbers. Conversely, no correlation was observed between levels of PAH contamination in the field and tadpole tolerance to BaP in the laboratory, indicating the absence of local adaptation for BaP tolerance in these populations. Nevertheless, the decrease of MNE formation due to BaP exposure with altitude suggests that high-altitude populations were intrinsically more resistant to BaP genotoxicity. We propose the hypothesis of a co-tolerance between UV-B and BaP in high-altitude common frog populations: local adaptation to prevent and/or repair DNA damage induced by UV-B could also protect these highland populations against DNA damage induced by BaP. The results of this study highlight the role of local adaptation along pollutant gradients leading to tolerance variation, which implies that is it necessary to take into account the history of exposure of each population and the existence of co-tolerance that can hide toxic effects of a

  8. Cloning of Interleukin-10 from African Clawed Frog (Xenopus tropicalis, with the Finding of IL-19/20 Homologue in the IL-10 Locus

    Directory of Open Access Journals (Sweden)

    Zhitao Qi

    2015-01-01

    Full Text Available Interleukin-10 (IL-10 is a pleiotropic cytokine that plays an important role in immune system. In the present study, the IL-10 gene of African clawed frog (Xenopus tropicalis was first cloned, and its expression pattern and 3D structure were also analyzed. The frog IL-10 mRNA encoded 172 amino acids which possessed several conserved features found in IL-10s from other species, including five-exon/four-intron genomic structure, conserved four cysteine residues, IL-10 family motif, and six α-helices. Real-time PCR showed that frog IL-10 mRNA was ubiquitous expressed in all examined tissues, highly in some immune related tissues including kidney, spleen, and intestine and lowly in heart, stomach, and liver. The frog IL-10 mRNA was upregulated at 24 h after LPS stimulation, indicating that it plays a part in the host immune response to bacterial infection. Another IL, termed as IL-20, was identified from the frog IL-10 locus, which might be the homologue of mammalian IL-19/20 according to the analysis results of the phylogenetic tree and the sequence identities.

  9. Cross-species functional analyses reveal shared and separate roles for Sox11 in frog primary neurogenesis and mouse cortical neuronal differentiation

    Directory of Open Access Journals (Sweden)

    Chao Chen

    2016-04-01

    Full Text Available A well-functioning brain requires production of the correct number and types of cells during development; cascades of transcription factors are essential for cellular coordination. Sox proteins are transcription factors that affect various processes in the development of the nervous system. Sox11, a member of the SoxC family, is expressed in differentiated neurons and supports neuronal differentiation in several systems. To understand how generalizable the actions of Sox11 are across phylogeny, its function in the development of the frog nervous system and the mouse cerebral cortex were compared. Expression of Sox11 is largely conserved between these species; in the developing frog, Sox11 is expressed in the neural plate, neural tube and throughout the segmented brain, while in the mouse cerebral cortex, Sox11 is expressed in differentiated zones, including the preplate, subplate, marginal zone and cortical plate. In both frog and mouse, data demonstrate that Sox11 supports a role in promoting neuronal differentiation, with Sox11-positive cells expressing pan-neural markers and becoming morphologically complex. However, frog and mouse Sox11 cannot substitute for one another; a functional difference likely reflected in sequence divergence. Thus, Sox11 appears to act similarly in subserving neuronal differentiation but is species-specific in frog neural development and mouse corticogenesis.

  10. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  11. Effects of water temperature on breeding phenology, growth and timing of metamorphosis of foothill yellow-legged frogs (Rana boylii) on the mainstem and selected tributaries of California's Trinity River - 2004-2009.

    Science.gov (United States)

    Clara Wheeler; James Bettaso; Donald Ashton; Hartwell Welsh

    2013-01-01

    The cold temperatures maintained in the Trinity River are beneficial to fish but may be problematic for foothill yellow-legged frogs. We examined the timing of breeding, reproductive output, and growth and development of tadpoles for populations of foothill yellow-legged frogs on the mainstem and six tributaries of the Trinity River. On the colder mainstem, onset of...

  12. Two-photon excited autofluorescence imaging of freshly isolated frog retinas.

    Science.gov (United States)

    Lu, Rong-Wen; Li, Yi-Chao; Ye, Tong; Strang, Christianne; Keyser, Kent; Curcio, Christine A; Yao, Xin-Cheng

    2011-06-01

    The purpose of this study was to investigate cellular sources of autofluorescence signals in freshly isolated frog (Rana pipiens) retinas. Equipped with an ultrafast laser, a laser scanning two-photon excitation fluorescence microscope was employed for sub-cellular resolution examination of both sliced and flat-mounted retinas. Two-photon imaging of retinal slices revealed autofluorescence signals over multiple functional layers, including the photoreceptor layer (PRL), outer nuclear layer (ONL), outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL), and ganglion cell layer (GCL). Using flat-mounted retinas, depth-resolved imaging of individual retinal layers further confirmed multiple sources of autofluorescence signals. Cellular structures were clearly observed at the PRL, ONL, INL, and GCL. At the PRL, the autofluorescence was dominantly recorded from the intracellular compartment of the photoreceptors; while mixed intracellular and extracellular autofluorescence signals were observed at the ONL, INL, and GCL. High resolution autofluorescence imaging clearly revealed mosaic organization of rod and cone photoreceptors; and sub-cellular bright autofluorescence spots, which might relate to connecting cilium, was observed in the cone photoreceptors only. Moreover, single-cone and double-cone outer segments could be directly differentiated.

  13. Irradiation of fish, shellfish and frog legs. A compilation of technical data for authorization and control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-01

    The International Consultative Group on Food Irradiation (ICGFI) was established on 9 May 1984 under the aegis of FAO, IAEA and WHO. ICGFI is composed of experts and other representatives designated by governments which have accepted the terms of the 'Declaration' establishing ICGFI and have pledged to make voluntary contributions, in cash or in kind, to carry out the activities of ICGFI. The functions of ICGFI are as follows: (a) To evaluate global developments in the field of food irradiation; (b) To provide a focal point of advice on the application of food irradiation to Member States and the Organization; and (c) To furnish information as required, through the Organization, to the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food, and to the Codex Alimentarius Commission. This publication contains the most up to date data on irradiation of fish, shellfish and frog legs. It is intended to assist governments in considering the authorization of this particular application of radiation processing of food and in ensuring its control in the facility and the control of irradiated food products moving in trade. It was prepared at the request of the International Consultative Group on Food Irradiation (ICGFI) in response to the increasing acceptance and application of irradiation to ensure hygienic quality of food, especially those of animal origin.

  14. The role of climatic and geological events in generating diversity in Ethiopian grass frogs (genus Ptychadena).

    Science.gov (United States)

    Smith, Megan L; Noonan, Brice P; Colston, Timothy J

    2017-08-01

    Ethiopia is a world biodiversity hotspot and harbours levels of biotic endemism unmatched in the Horn of Africa, largely due to topographic-and thus habitat-complexity, which results from a very active geological and climatic history. Among Ethiopian vertebrate fauna, amphibians harbour the highest levels of endemism, making amphibians a compelling system for the exploration of the impacts of Ethiopia's complex abiotic history on biotic diversification. Grass frogs of the genus Ptychadena are notably diverse in Ethiopia, where they have undergone an evolutionary radiation. We used molecular data and expanded taxon sampling to test for cryptic diversity and to explore diversification patterns in both the highland radiation and two widespread lowland Ptychadena . Species delimitation results support the presence of nine highland species and four lowland species in our dataset, and divergence dating suggests that both geologic events and climatic fluctuations played a complex and confounded role in the diversification of Ptychadena in Ethiopia. We rectify the taxonomy of the endemic P. neumanni species complex, elevating one formally synonymized name and describing three novel taxa. Finally, we describe two novel lowland Ptychadena species that occur in Ethiopia and may be more broadly distributed.

  15. Indirana chiravasi, a new species of Leaping Frog (Anura: Ranixalidae from Western Ghats of India

    Directory of Open Access Journals (Sweden)

    A.D. Padhye

    2014-09-01

    Full Text Available Indirana chiravasi, a new species of leaping frog is described from the northern Western Ghats around Amboli, Sindhudurg District, Maharashtra, India. It differs from all its congeners based on a combination of characters including presence of median single internal vocal sac, head longer than wide, distinct canthus rostralis, tympanum 2/3rd to 3/4th the diameter of eye, vomerine teeth in two oblique series at the posterior border of choanae, long midventral lingual papilla, first finger longer than or equal to second, presence of double outer palmer tubercle, thin and elongated inner metatarsal tubercle, absence of outer metatarsal tubercle, webbing moderate, dorsal skin with glandular folds but without warts, ventral skin smooth without mottling and palms and soles dark brown. Molecular analysis based on mitochondrial 12S and 16S genes and nuclear rhodopsin and rag1 genes suggests that the species is genetically distinct from other species for which genetic data is available. Preliminary observations on the development of the species are also provided. We also provide genetic data and images for Indirana gundia collected from the type locality.

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

    Science.gov (United States)

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

    2016-09-07

    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.

  17. Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows.

    Science.gov (United States)

    Cui, Jianguo; Tang, Yezhong; Narins, Peter M

    2012-06-23

    During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside calls positively correlate with the area of the burrow entrance and the depth of the burrow, respectively. When given a choice between outside and inside calls played back alternately, more than 70 per cent of the females (33/47) chose inside calls. These results demonstrate that males of this species faithfully advertise whether or not they possess a nest to potential mates by vocal communication, which probably facilitates optimal mate selection by females. These results revealed a novel function of advertisement calls, which is consistent with the wide variation in both call complexity and social behaviour within amphibians.

  18. Sperm storage in the oviduct of the internal fertilizing frog Ascaphus truei.

    Science.gov (United States)

    Sever, D M; Moriarty, E C; Rania, L C; Hamlett, W C

    2001-04-01

    This study provides the first descriptions of sperm storage at the tissue and cellular levels in a female frog or toad. Oviducal anatomy was studied by light and electron microscopy in Ascaphus truei from north coastal California. Ascaphus truei is one of the few species of anurans in which fertilization is internal. Unlike other anurans with internal fertilization, however, mating in A. truei consists of a unique combination of amplectic and copulatory mechanisms that we term "copulexus." Posterior to a short, aglandular infundibular region, the oviduct possesses: 1) a proximal, convoluted ampullary region where intrinsic tubular glands secrete gelatinous envelopes around eggs; 2) a middle ovisac region where fertilization occurs; and 3) a distal oviducal sinus formed by medial junction of the ovisacs. Sperm storage tubules (SSTs) occur in the anterior portions of the ovisacs and consist of simple tubular glands. SSTs and the rest of the oviducal lining stain positively with the periodic acid-Schiff's procedure for neutral carbohydrates and this reaction is especially intense in reproductively active females. Sperm were found in the SSTs of gravid females as well as some nonvitellogenic females. The sperm are in orderly bundles in the SSTs, and although occasionally sperm nuclei were embedded in the epithelium, no evidence for spermiophagy was found. Oviducal sperm storage in A. truei is homoplastic, with closest structural similarities to squamate reptiles. Oviduct/sperm design constraints appear to limit the options for expression of features associated with oviducal sperm storage. Copyright 2001 Wiley-Liss, Inc.

  19. Influence of CO2 on electrophysiology and ionic permeability of the basolateral membrane of frog skin

    International Nuclear Information System (INIS)

    Stoddard, J.S.

    1984-01-01

    When short-circuited epithelia of frog skin bathed in an alkaline Ringer solution equilibrated with room air, are exposed to a Ringer solution equilibrated with 5% CO 2 , inhibition of transepithelial Na + transport is observed accompanied by a marked depolarization of the basolateral membrane voltage as measured with intracellular microelectrodes. To study further the mechanisms involved, basolateral membrane influxes and effluxes of 24 Na, 42 K, and 36 Cl were measured in control and CO 2 -treated isolated epithelia. In control epithelia, studies of the bidirectional 24 Na fluxes confirmed the existence of an important basolateral membrane permeability to Na + . In control epithelia, the apical membranes of the cells were found to be virtually impermeable to Cl - , while basolateral membranes were highly permeable to Cl - . Although CO 2 caused a partial inhibition of pump activity as assessed from decreases of pump-mediated Na + efflux and K + influx, CO 2 caused little or no change of the leak influx of Na + or K + . K + efflux was increased markedly with CO 2 resulting in a net loss of K + from the cells. Cl - influx was increased and Cl - efflux was decreased by CO 2 leading to a net influx of Cl - . Analysis of the data according to criteria involving changes of flux, ionic equilibrium potentials, mass and charge balance restrictions indicated that the principle changes involve a transient decrease in electrical conductance to K + with a concurrent increase in electrical conductance to HCO 3 - (OH - or H + ) of the basolateral membranes of the cells

  20. Kin discrimination in cannibalistic tadpoles of the Green Poison Frog, Dendrobates auratus (Anura, Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Heather M. Gray

    2009-07-01

    Full Text Available Cannibalizing a related individual can reduce the inclusive fitness of the cannibal. Hence, mechanisms that allow a tadpole to recognize and modify its behavior toward kin may reduce the inclusive fitness costs of cannibalism. Alternatively, ecological factors may cause preferential treatment of kin to be too costly to be favored by selection. We tested these two predictions in the Green Poison Frog, Dendrobates auratus. The effect of kinship on larval cannibalism was examined through a series of kin-discrimination trials. The behavior of large tadpoles was observed when presented with two small, tethered tadpoles, one a clutchmate and one an unrelated tadpole. In these simultaneous presentation tests, tadpoles displayed a significant preference for attacking kin. In a series of timed trials, pairs of unequally sized tadpoles were placed together in containers. The majority (70% of large tadpoles took less than24 hr to consume the small tadpole. Kinship did not affect the survival time of the small tadpole. Our results are consistent with observations that D. auratus is an indiscriminate predator. As conspecifics may be serious competitors, their swift elimination would be an advantage, particularly in the small, nutrient-poor poolsused by this species.