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Sample records for american bullfrog rana

  1. Infestation of Wild-caught American Bullfrogs (Rana catesbeiana) by Multiple Species of Metazoan Parasites

    National Research Council Canada - National Science Library

    Lemke, Laura B; Dronen, Norman; Fox, James G; Nambiar, Prashant R

    2008-01-01

    The American bullfrog (Rana catesbeiana) is an aquatic, carnivorous member of the family Ranidae that is used extensively in physiology education programs and in various physiology, toxicology, sensorineural, and genetics research...

  2. Body size affects the predatory interactions between introduced American Bullfrogs (Rana catesbeiana) and native anurans in China: An experimental study

    Science.gov (United States)

    Wang, Y.; Guo, Z.; Pearl, C.A.; Li, Y.

    2007-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have established breeding populations in several provinces in China since their introduction in 1959. Although Bullfrogs are viewed as a potentially important predator of Chinese native anurans, their impacts in the field are difficult to quantify. We used two experiments to examine factors likely to mediate Bullfrog predation on native anurans. First, we examined effects of Bullfrog size and sex on daily consumption of a common Chinese native (Rana limnocharis). Second, we examined whether Bullfrogs consumed similar proportions of four Chinese natives: Black-Spotted Pond Frog (Rana nigromaculata), Green Pond Frog (Rana plancyi plancyi), Rice Frog (R. limnocharis), and Zhoushan Toad (Bufo bufo gargarizans). We found that larger Rana catesbeiana consumed more R. limnocharis per day than did smaller R. catesbeiana, and that daily consumption of R. limnocharis was positively related to R. catesbeiana body size. When provided with adults of four anurans that differed significantly in body size, R. catesbeiana consumed more individuals of the smallest species (R. limnocharis). However, when provided with similarly sized juveniles of the same four species, R. catesbeiana did not consume any species more than expected by chance. Our results suggest that body size plays an important role in the predatory interactions between R. catesbeiana and Chinese native anurans and that, other things being equal, smaller species and individuals are at greater risk of predation by R. catesbeiana. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  3. Cardiovascular responses to catecholamines at 12 degrees C in the American bullfrog (Rana catesbeiana).

    Science.gov (United States)

    Herman, C A; Robleto, D O; Mata, P L; Heller, R S

    1986-10-01

    The effects of epinephrine, norepinephrine, phenylephrine, and isoproterenol on blood pressure and heart rate were studied in cannulated American bullfrogs, Rana catesbeiana. The bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. In warm-acclimated (22 degrees C) bullfrogs, preinjection mean systemic arterial pressure (SAP) prior to experimental treatment was 13.1 +/- 0.7 mm Hg. Preinjection heart rate was 34.8 +/- 1.8 beats per minute. These parameters were lower in cold-acclimated (12 degrees C) bullfrogs. Cold-acclimated animals had mean SAP values of 8.2 +/- 0.3 mm Hg, and heart rate was 11.1 +/- 1.1 beats per minute. Epinephrine, norepinephrine, and phenylephrine increased blood pressure to an equivalent degree in warm- and cold-acclimated animals. Dose-related decreases in heart rate in response to these catecholamines were observed in warm- but not in cold-acclimated bullfrogs. Warm-acclimated animals were more responsive to isoproterenol from 0.03 micrograms/kg body weight (bw) to 10 micrograms/kg bw than were cold-acclimated animals. The response to isoproterenol was effectively blocked by propranolol (5 mg/kg bw) in both warm- and cold-acclimated animals. Propranolol alone decreased mean SAP in both warm- and cold-acclimated animals, suggesting blockade of endogenous sympathetic activity. Beta receptor response thus appears diminished, but not absent at 12 degrees C. However, the alpha receptors responsible for elevation of blood pressure equally responsive at 12 degrees and 22 degrees C.

  4. Stomach contents from invasive American bullfrogs Rana catesbeiana (= Lithobates catesbeianus on southern Vancouver Island, British Columbia, Canada

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    Kevin Jancowski

    2013-03-01

    Full Text Available Invasive alien American bullfrog populations are commonly identified as a pernicious influence on the survival of native species due to their adaptability, proliferation and consequent ecological impacts through competition and predation. However, it has been difficult to determine conclusively their destructive influence due to the fragmentary and geographically dispersed nature of the historical database. An expanding meta-population of invasive American bullfrogs, Rana catesbeiana (= Lithobates catesbeianus, became established on southern Vancouver Island, British Columbia, Canada in the mid- to late 1980s. An on-going bullfrog control program begun in 2006 offered a unique opportunity to examine the stomach contents removed from 5,075 adult and juvenile bullfrogs collected from 60 sites throughout the active season (April to October. Of 15 classes of organisms identified in the diet, insects were numerically dominant, particularly social wasps and odonates (damselflies and dragonflies. Seasonality and site-specific habitat characteristics influenced prey occurrence and abundance. Native vertebrates in the diet included fish, frogs, salamanders, snakes, lizards, turtles, birds, and mammals, including some of conservation concern. Certain predators of bullfrog tadpoles and juveniles are commonly preyed upon by adult bullfrogs, thereby suppressing their effectiveness as biological checks to bullfrog population growth. Prey species with anti-predator defences, such as wasps and sticklebacks, were sometimes eaten in abundance. Many prey species have some type of anti-predator defence, such as wasp stingers or stickleback spines, but there was no indication of conditioned avoidance to any of these. Results from this study reinforce the conclusion that, as an invasive alien, the American bullfrog is an opportunistic and seemingly unspecialized predator that has a uniquely large and complex ecological footprint both above and below the water surface.

  5. Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana raised in Malaysia

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    SW Lee

    2009-01-01

    Full Text Available A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3% cases of sensitivity and 61 (7.3% cases of partial sensitivity. Meanwhile, 297 (35.4% bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0%. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.

  6. Antibiotic Resistance and Heavy Metals Tolerance in Gram-Negative Bacteria from Diseased American Bullfrog (Rana catesbeiana) Cultured in Malaysia

    Institute of Scientific and Technical Information of China (English)

    M Na-jian; S W Lee; W Wendy; L W Tee; M Nadirah; S H Faizah

    2009-01-01

    A total of 140 bacterial isolates have been successfully isolated from various organs of diseased American bullfrog (Rana catesbeiana) cultured in Malaysia. The most frequently isolated bacteria was Edwardsiella spp. (46 isolates) followed by Aeromonas spp. (33 isolates), Flavobacterium spp. (31 isolates), and Vibrio spp. (30 isolates). Majority of the bacterial isolates were found sensitive to furazolidone (85.0%), chloramphenicol (85.0%), oxolinic acid (90.0%), florfenicol (95.0%), and flumequine (97.5%). On the other hand, most of the bacterial isolates were resistant to oleandomycin (77.5%) and lincomycin (87.5%). Nitrofurantoin and flumequine can be inhibited the growth of all of Vibrio spp. whereas all isolates of Edwardsiella spp. were found sensitive to florfenicol and flumequine. Multiple antibiotic resistance (MAR) index were in range of 0.30-0.40, indicating that bacterial isolates from cultured bullfrogs may have received high risk exposure to the tested antibiotics. In addition, 90-100% of the isolates were resistant to copper, cadmium, and chromium. These results provided insight information on tolerance level of bacterial isolates from cultured bullfrogs to 21 antibiotics as well as heavy metals.

  7. Identification of Elizabethkingia meningoseptica from American bullfrog (Rana catesbeiana farmed in Sabah, Malaysia using PCR method and future management of outbreak

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    Zainuri, N.

    2013-01-01

    Full Text Available Aims: High demand for frog meat in Malaysia especially the American bullfrog (Rana catesbeiana has promoted intensive farming of the animal. However, the farming of American bullfrog is restricted by the occurrence of diseases. This study reports the first isolation of Elizabethkingia meningoseptica from specimens of American bullfrog that suffer from cataract and ‘red-leg’ syndrome.Methodology and Result: The pathogen was isolated from eyes and internal organs (liver, kidney and spleen of thediseased bullfrog specimens. All the bacterial isolates were subjected to phenotypic characterization and antibiotic susceptibility assay, and further identified by using the 16S rDNA sequencing analysis. We designed two pair of specific PCR primers (22-25 mers which are complimentary to the β-lactamase gene in the reference strain ofE. meningoseptica ATCC49470. The result showed all the bacterial isolates shared similar phenotypic characters and antibiotic susceptibility. BLAST analysis of the 16S rDNA sequences indicated that the bacterial isolates had very high sequence homology (100% with E. meningospetica ATCC49470 and E. meningoseptica isolates from mosquito. The two PCR primers were very specific to E. meningoseptica isolates of this study. Conclusion, significance and impact of study: This is the first isolation and characterization of bacterial pathogen, E. meningoseptica in cultured American bullfrog (Rana catesbeina that suffered from eye cataract and ‘red-leg’syndrome in Sabah, Malaysia. It is suspected that one of the possible transmission routes of the bacterial pathogen could be via mosquito bites. The findings suggest that there is urgent requirement for standard guideline of good farming practice to be adopted in frog farms throughout the country. Such a guideline can help in minimizing economic losses, preventing transmission of the zoonotic bacterial pathogen to farm workers, and sustaining the industry in Malaysia andupgrading

  8. Expression of steroidogenic acute regulatory protein (StAR) in male American bullfrog (Rana catesbeiana) and preliminary evaluation of the response to TNT.

    Science.gov (United States)

    Paden, Norka E; Carr, James A; Kendall, Ronald J; Wages, Mike; Smith, Ernest E

    2010-06-01

    We examined the expression of steroidogenic acute regulatory (StAR) protein mRNA in the American bullfrog (Rana catesbeiana). Primers and probes were designed to obtain a partial sequence of bullfrog StAR cDNA consisting of 349 base pairs. Quantitative PCR analysis of StAR mRNA equivalents was performed in tissues of juvenile and adult bullfrogs. In this study 18S mRNA was used as an internal standard. There were no differences in the expression of 18S RNA among tissues or between age groups. In juvenile males, the rank order for the constitutive levels of StAR was testes>skin>brain>kidneys. In adult males, StAR mRNA equivalent was greatest in testes, followed by kidneys, brain, and skin. In addition, stimulation and induction of testicular StAR by human chorionic gonadotropin significantly increased expression of StAR at 2, 4, and 6h after injection. Preliminary evaluation of 2, 4, 6-trinitrotoluene (TNT) revealed that acute exposure is associated with reduction of StAR mRNA expression. The information provided in this study will be useful for future research on StAR gene expression in amphibian reproductive biology and the development of reproductive biomarkers.

  9. A new record for American Bullfrog (Lithobates catesbeianus in San Juan, Argentina Nuevo registro de rana toro americana (Lithobates catesbeianus en San Juan, Argentina

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    Eduardo Sanabria

    2011-03-01

    Full Text Available We report a new record of Lithobates catesbeianus (American bullfrog from Argentina. L. catesbeianus was first introduced to San Juan Province 11 years ago in Calingasta Department, where the habitat is pre-cordilleran. The new record is for Zonda Department, San Juan Province, in the Monte desert region. Here, L. catesbeianus uses artificial ponds for reproduction and tadpole development. These ponds receive water from an irrigation system that connects the whole agriculture land in the region. The tadpoles use the irrigation canals to move among ponds. We suggest that legislation should be established to prevent future invasions and to achieve sustainable management of the wild American bullfrog populations in San Juan. Prevention of future invasion and management of established populations of this species requires the cooperation of numerous stake holders.Se presenta un nuevo registro de Lithobates catesbeianus (rana toro americana en Argentina. L. catesbeianus fue introducida por primera vez a la provincia de San Juan hace 11 años en el Departamento Calingasta, donde el hábitat es pre-cordillerano. El nuevo registro es para el Departamento Zonda en la provincia de San Juan, en el desierto del Monte. En este sitio, L. catesbeianus usa estanques artificiales para la reproducción y desarrollo del renacuajo. Los estanques reciben agua de un sistema de riego que conecta todas las tierras de la agricultura en la región. Los renacuajos utilizan los canales de riego para moverse entre los estanques. Sugerimos que se establezcan leyes para prevenir invasiones futuras y para lograr un manejo integrado de las poblaciones silvestres de rana toro que se encuentran en San Juan. La prevención de futuras invasiones y el manejo de las poblaciones establecidas de esta especie requieren la cooperación de numerosas entidades tanto gubernamentales como privadas.

  10. Ovine thyroid stimulating hormone (TSH) heterologously stimulates production of thyroid hormones from Chinese soft-shell turtle (Pelodiscus sinensis) and bullfrog (Rana catesbeiana and Rana rugulosa) thyroids in vitro.

    Science.gov (United States)

    Huang, Wei-Tung; Chien, Jung-Tsun; Weng, Ching-Feng; Jeng, Yung-Yue; Lu, Li-Chia; Yu, John Yuh-Lin

    2009-06-01

    Thyroid hormones are important for regulating a variety of developmental processes in vertebrates, including growth, differentiation, metamorphosis, and oxidative metabolism. In particular, this study focused on the in vitro production of thyroxine (T(4)) and triiodothyronine (T(3)) from thyroids in American bullfrogs (Rana catesbeiana), Chinese bullfrogs (Rana rugulosa Wiegmann), and Chinese soft-shell turtles (Pelodiscus sinensis) treated with ovine thyroid stimulating hormone (TSH) at different culture intervals (2, 4, 8, and 12 h) and dosages (1, 10, 50 or 100 ng). The levels of T(4) and T(3) in the tested animals were elevated upon stimulation in a time- and dose-dependent manner, indicating de novo synthesis of T(4) and T(3). Significantly higher hormone levels were observed in the Chinese bullfrog compared to the other two species, for both the time-course and dose-response experiments. Although the bullfrog secreted significantly higher levels of T(4) and T(3), a higher T(4)-conversion capacity was found in the Chinese soft-shell turtle. The highest ratios of T(3) to T(4) were observed in the American bullfrog and Chinese soft-shell turtle for the time-course and dose-response experiments, respectively. These findings suggest that the Chinese soft-shell turtle and bullfrog thyroids can accept ovine TSH for T(4)- and T(3)-formation in a time- and dose-dependent manner, supporting the hypothesis that the binding interactions between TSHs and thyroidal receptors are conserved in vertebrates.

  11. WIENER KERNEL ANALYSIS OF INNER-EAR FUNCTION IN THE AMERICAN BULLFROG

    NARCIS (Netherlands)

    VANDIJK, P; WIT, HP; SEGENHOUT, JM; TUBIS, A

    1994-01-01

    The response of 17 primary auditory nerve fibers in the American bullfrog (Rana catesbeiana) to acoustic noise stimulation of the tympanic membrane was recorded. For each fiber, the first- and second-order Wiener kernels, k(1)(tau(1)) and k(2)(tau(1),tau(2)), were computed by cross correlation of th

  12. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  13. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    Science.gov (United States)

    Zhang, Junjie; Zou, Wenzheng; Yan, Qingpi

    2008-08-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  14. First evidence of Batrachochytrium dendrobatidis in China: discovery of chytridiomycosis in introduced American bullfrogs and native amphibians in the Yunnan Province, China.

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    Bai, Changming; Garner, Trenton W J; Li, Yiming

    2010-08-01

    Although the chytrid fungus Batrachochytrium dendrobatidis (Bd), the etiological agent of amphibian chytridiomycosis, has been implicated in mass mortality and population declines on several continents around the world, there have been no reports on the presence of Bd infections in amphibians in China. We employed quantitative PCR and histological techniques to investigate the presence of Bd in introduced North American bullfrogs (Rana catesbeiana) (referred to hereafter as bullfrog) and native amphibians in bullfrog-invaded areas of the Yunnan Province, China. A total of 259 samples at five wild sites were collected between June and September in 2007 and 2008, including bullfrogs and four native amphibian species (Rana pleuraden, Rana chaochiaoensis, Odorrana andersonii, and Bombina maxima). In addition, 37 samples of adult bullfrogs were obtained from a food market. Bd infections were discovered in bullfrogs and three native amphibian species from all of the surveyed sites. Of the 39 Bd-positive samples, 35 were from wild-caught bullfrog tadpoles, postmetamorphic bullfrogs, R. pleuraden, R. chaochiaoensis, and O. andersonii, and four were from adult bullfrogs from the market. Our results provide the first evidence of the presence of Bd in Chinese amphibians, suggesting that native amphibian diversity in China is at risk from Bd. There is an urgent need to monitor the distribution of Bd in amphibians in China and understand the susceptibility of native amphibian species to chytridiomycosis. Strict regulations on the transportation of bullfrogs and the breeding of bullfrogs in markets and farms should be drafted in order to stop the spread of Bd by bullfrogs.

  15. Relationships among developmental stage, metamorphic timing, and concentrations of elements in bullfrogs (Rana catesbeiana)

    Energy Technology Data Exchange (ETDEWEB)

    Snodgrass, J.W.; Hopkins, W.A.; Roe, J.H. [Towson University, Towson, MD (United States). Dept. for Biological Science

    2003-07-01

    We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered in the contaminated basin and metamorphosed in the spring were analyzed for whole-body concentrations of Al, V, Cr, Ni, Cu, As, Pb, Cd, Zn, Ag, Sr, and Se. After the effects of dry mass were removed, tissue concentrations of six elements (Al, V, Cr, Ni, Cu, As, and Pb) decreased from the late larval stage through metamorphosis. Decreases in concentrations through metamorphosis ranged from 40% for Cu to 97% for Al. Tissue concentrations of these elements were also similar or higher in spring; Al and Cr concentrations were 34 and 90% higher in the spring, respectively, whereas As, Ni, Cu, and Pb concentrations were {lt} 10% higher. Concentrations of Cd, Se, and Ag varied among seasons but not among stages; Cd and Ag concentrations were 40 and 62% lower, respectively, and Se concentrations were 21% higher in spring. Concentrations of Zn varied only among stages; concentrations decreased gradually through late larval stage and then increased through metamorphosis. Concentrations of Sr varied among stages, but this variation was dependent on the season. Concentrations of Sr were higher in larval stages during the spring, but because concentrations of Sr increased 122% through metamorphosis in the fall and only 22% in the spring, concentrations were higher in fall metamorphs when compared with spring metamorphs. Our results indicate that metamorphosis and season of metamorphosis affects trace element concentrations in bullfrogs and may have important implications for the health of juveniles and the transfer of pollutants from the aquatic to the terrestrial environment.

  16. Malnutrition in farm-cultured bullfrog (Rana catesbeiana fed on bovine milled lung in Argentina

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    J A Coppo, N B Mussart

    2005-11-01

    Full Text Available The true nutritional requirements of bullfrog (Rana catesbeiana, Anura: Ranidae are still controversial. In Argentine hatcheries, bullfrogs are fed on commercial balanced diets elaborated for fish; high price of balanced food decreases the relationship cost / benefit. This study had the objective to verify the nutritious effectiveness of bovine lung, by means of liveweight gains and metabolic and nutritional biochemical indicators controls. Eighty frogs were randomly divided into experimental (E and control (C groups of 40 animals each. Controls consumed a fish commercial balanced diet (23% protein in dry matter, DM, while those in group E were fed on bovine milled lung (16% protein, DM. Food was administered at a rate of 5% of liveweight/day (DM for both groups. The weighings and collection of samples were made on days 0 and 120. One frog of group C and 8 frogs of group E died during the study. Control animals did not register physical abnormalities. On the other hand, emaciation, adynamia, weakness, anorexy, and skin abnormal coloration were verified in some amphibians of group E. At the end of the study, liveweight and albumin, creatinine, urea, cholesterol, triglycerides, glucose, phosphorous and magnesium serum values, were significantly lower in group E than in group C (p < 0.05. This changes are attributed to metabolic imbalances related to malnutrition and reveal that bovine lung is not an appropriate food for captive bullfrog.

  17. Invasion of American bullfrogs along the Yellowstone River

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    Sepulveda, Adam; Layhee, Megan J.; Stagliano, Dave; Chaffin, Jake; Begley, Allison; Maxell, Bryce A.

    2015-01-01

    The American bullfrog (Lithobates catesbeianus) is a globally distributed invasive species that was introduced to the Yellowstone River floodplain of Montana. Knowledge about floodplain habitat features that allow for bullfrog persistence and spread will help identify effective control strategies. We used field surveys in 2010, 2012 and 2013 to describe bullfrog spread in the Yellowstone River floodplain and the habitat features that are associated with bullfrog occupancy and colonization. Bullfrogs in our study area expanded from ~ 60 km in 2010 to 106 km in 2013, and are spreading to up- and downstream habitats. The number of breeding sites (i.e., presence of bullfrog eggs or larvae) increased from 12 sites in 2010 to 45 sites in 2013. We found that bullfrogs were associated with deeper waters, emergent vegetation and public-access sites, which are habitat features that characterize permanent waters and describe human-mediated introductions. Control strategies that reduce the hydroperiod of breeding sites may help to limit bullfrog persistence and spread, while an increase in public outreach and education may help prevent further bullfrog introductions at public-access sites.

  18. Frog community responses to recent American bullfrog invasions

    Institute of Scientific and Technical Information of China (English)

    Yiming LI; Zhunwei KE; Yihua WANG; Tim M. BLACKBURN

    2011-01-01

    Native species may decline quickly when confronted with an exotic species to which they are not adapted. The extent of decline may depend on the abundance of an invader and the length of time since it first arrived in the community (residence time), and the interaction between these two variables. We tested these effects using data on the effects of American bullfrog Lithobates catesbeianus invasion on native frog communities in 65 permanent lentic waters on islands in the Zhoushan Archipelago, China. We examined variation in native frog abundance and species richness in relation to features of the American bullfrog invasion, habitat disturbance, characteristics of the water body and fish communities and the presence of red swamp crayfish.Bullfrog invaded sites had lower native frog density and species richness, higher submerged vegetation cover and greater frequency of repairs to the water body than did non-invaded sites. The minimum adequate general linear mixed models showed that both native frog density and species richness were negatively related to post-metamorphosis bullfrog density, and that native frog species richness was also positively related to the vegetation cover. There was no effect on either native frog density or species richness of residence time or its interaction with bullfrog density, or of the abundance of bullfrog tadpoles. The results suggested that post-metamorphosis bullfrogs had impacts on native frog communities in the islands, and that the extents of these impacts are proportional to post-metamorphosis bullfrog density.

  19. Frog community responses to recent American bullfrog invasions

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    Yiming LI, Zhunwei KE, Yihua WANG, Tim M. BLACKBURN

    2011-02-01

    Full Text Available Native species may decline quickly when confronted with an exotic species to which they are not adapted. The extent of decline may depend on the abundance of an invader and the length of time since it first arrived in the community (residence time, and the interaction between these two variables. We tested these effects using data on the effects of American bullfrog Lithobates catesbeianus invasion on native frog communities in 65 permanent lentic waters on islands in the Zhoushan Archipelago, China. We examined variation in native frog abundance and species richness in relation to features of the American bullfrog invasion, habitat disturbance, characteristics of the water body and fish communities and the presence of red swamp crayfish. Bullfrog invaded sites had lower native frog density and species richness, higher submerged vegetation cover and greater frequency of repairs to the water body than did non-invaded sites. The minimum adequate general linear mixed models showed that both native frog density and species richness were negatively related to post-metamorphosis bullfrog density, and that native frog species richness was also positively related to the vegetation cover. There was no effect on either native frog density or species richness of residence time or its interaction with bullfrog density, or of the abundance of bullfrog tadpoles. The results suggested that post-metamorphosis bullfrogs had impacts on native frog communities in the islands, and that the extents of these impacts are proportional to post-metamorphosis bullfrog density [Current Zoology 57 (1: 83–92, 2011].

  20. Thermo-Oxidative Stability Evaluation of Bullfrog (Rana catesbeiana Shaw Oil

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    Renata Rutckeviski

    2017-04-01

    Full Text Available Bullfrog oil (BO, a natural product obtained from recycling of adipose tissue from the amphibian Rana catesbeiana Shaw, has been recently evaluated as a therapeutic activity ingredient. This work aimed to evaluate the long-term and accelerated thermal oxidative stabilities of this product, which is a promising raw material for emulsion technology development. BO was extracted from amphibian adipose tissue at 70 °C with a yield of 60% ± 0.9%. Its main fatty acid compounds were oleic (30.0% and eicosapentaenoic (17.6% acids. Using titration techniques, BO showed peroxide, acid, iodine and saponification indices of 1.92 mEq·O2/kg, 2.95 mg·KOH/g oil, 104.2 g I2/100 g oil and 171.2 mg·KOH/g oil, respectively. In order to improve the accelerated oxidative stability of BO, synthetic antioxidants butylhydroxytoluene (BHT and buthylhydroxyanisole (BHA were used. The addition of BHT increased the oxidation induction time compared to the pure oil, or the oil containing BHA. From the results, the best oil-antioxidant mixture and concentration to increase the oxidative stability and allow the oil to be a stable raw material for formulation purposes was derived.

  1. Cathelicidins from the bullfrog Rana catesbeiana provides novel template for peptide antibiotic design.

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    Guiying Ling

    Full Text Available Cathelicidins, a class of gene-encoded effector molecules of vertebrate innate immunity, provide a first line of defense against microbial invasions. Although cathelicidins from mammals, birds, reptiles and fishes have been extensively studied, little is known about cathelicidins from amphibians. Here we report the identification and characterization of two cathelicidins (cathelicidin-RC1 and cathelicidin-RC2 from the bullfrog Rana catesbeiana. The cDNA sequences (677 and 700 bp, respectively encoding the two peptides were successfully cloned from the constructed lung cDNA library of R. catesbeiana. And the deduced mature peptides are composed of 28 and 33 residues, respectively. Structural analysis indicated that cathelicidin-RC1 mainly assumes an amphipathic alpha-helical conformation, while cathelicidin-RC2 could not form stable amphipathic structure. Antimicrobial and bacterial killing kinetic analysis indicated that the synthetic cathelicidin-RC1 possesses potent, broad-spectrum and rapid antimicrobial potency, while cathelicidin-RC2 exhibited very weak antimicrobial activity. Besides, the antimicrobial activity of cathelicidin-RC1 is salt-independent and highly stable. Scanning electron microscopy (SEM analysis indicated that cathelicidin-RC1 kills microorganisms through the disruption of microbial membrane. Moreover, cathelicidin-RC1 exhibited low cytotoxic activity against mammalian normal or tumor cell lines, and low hemolytic activity against human erythrocytes. The potent, broad-spectrum and rapid antimicrobial activity combined with the salt-independence, high stability, low cytotoxic and hemolytic activities make cathelicidin-RC1 an ideal template for the development of novel peptide antibiotics.

  2. Ghrelin receptor in two species of anuran amphibian, bullfrog (Rana catesbeiana and Japanese tree frog (Hyla japonica

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    Hiroyuki eKaiya

    2011-09-01

    Full Text Available We identified cDNA encoding a functional growth hormone secretagogue-receptor 1a (GHS-R1a, ghrelin receptor in two species of anuran amphibian, bullfrog (Rana catesbeiana and Japanese tree frog (Hyla japonica. Deduced receptor protein for bullfrog and Japanese tree frog (tree frog was comprised of 374- and 371-amino acids, respectively. The two receptors showed 86% identity with each other, and phylogenetic analysis revealed that the two receptors belong to the same category with tetrapods. In functional analyses, ghrelin and GHS-R1a agonists increased intracellular Ca2+ concentration in HEK293 cell that transfected each receptor cDNA, but ligand selectivity of ghrelin with Ser3 and Thr3 was not observed between the two receptors. Bullfrog GHS-R1a mRNA was mainly expressed in the brain, stomach and testis. In the brain, the gene expression was detected in the diencephalon and mesencephalon, but not in the pituitary. Tree frog GHS-R1a mRNA was predominantly expressed in the gastrointestinal tract and ovary, but not detected in the pituitary. In bullfrog stomach, GHS-R1a mRNA expression increased at 10 days after fasting, but not in the brain. In tree frog, GHS-R1a mRNA expression increased in the brain, stomach and ventral skin by 10-days fasting, and in the stomach and ventral skin by a dehydration treatment. Intracerebroventricular injection of ghrelin in dehydrated tree frog did not affect water absorption from the ventral skin. These results suggest that ghrelin is involved in energy homeostasis and possibly in osmoregulation in frogs.

  3. Effects of testosterone on contractile properties of sexually dimorphic forelimb muscles in male bullfrogs (Rana catesbeiana, Shaw 1802

    Directory of Open Access Journals (Sweden)

    Aaron R. Kampe

    2013-07-01

    This study examined the effects of testosterone (T on the contractile properties of two sexually dimorphic forelimb muscles and one non-dimorphic muscle in male bullfrogs (Rana catesbeiana, Shaw 1802. The dimorphic muscles in castrated males with testosterone replacement (T+ achieved higher forces and lower fatigability than did castrated males without replaced testosterone (T0 males, but the magnitude of the differences was low and many of the pair-wise comparisons of each muscle property were not statistically significant. However, when taken as a whole, the means of seven contractile properties varied in the directions expected of masculine values in T+ animals in the sexually dimorphic muscles. Moreover, these data, compared with previous data on male and female bullfrogs, show that values for T+ males are similar to normal males and are significantly different from females. The T0 males tended to be intermediate in character between T+ males and females, generally retaining masculine values. This suggests that the exposure of young males to T in their first breeding season produces a masculinizing effect on the sexually dimorphic muscles that is not reversed between breeding seasons when T levels are low. The relatively minor differences in contractile properties between T+ and T0 males may indicate that as circulating T levels rise during breeding season in normal males, contractile properties can be enhanced rapidly to maximal functional levels for breeding success.

  4. Vehicle effects on in vitro transdermal absorption of sevoflurane in the bullfrog, Rana catesbeiana.

    Science.gov (United States)

    Ardente, Amanda J; Barlow, Beth M; Burns, Patrick; Goldman, Rebecca; Baynes, Ronald E

    2008-05-01

    The experimental objectives were to identify a vehicle which produces a homogenous formulation when combined with the anesthetic solution sevoflurane and understand the dermal absorption of sevoflurane in silastic membranes and amphibian skin in vitro utilizing a flow-through diffusion system. Seven vehicles were evaluated in varying ratios with 5 formulations resulting in the desired homogenous consistency for practical application. Sevoflurane diffusion across silastic membranes was influenced by pluronic/lecithin organogel (PLO), pluronic F 127 20% gel, and sterile lube. Flux and permeability across silastic membranes were significantly greater in sterile lube than in the other formulations. While no significant vehicle effects were observed in bullfrog skin, the flux-time profiles suggest that sevoflurane diffusion in bullfrog skin may be positively influenced by PLO. Future in vivo studies are required to assess sevoflurane retention after removal of these formulations to more accurately control the plane of anesthesia in amphibians. Copyright © 2007 Elsevier B.V. All rights reserved.

  5. A Study on the Chromosomes in Bullfrog Rana catesbeiana%牛蛙(Rana catesbeiana)染色体研究

    Institute of Scientific and Technical Information of China (English)

    朱传炳; 王瑛

    2006-01-01

    对牛蛙(Rana catesbeiana,Shaw)的染色体组型进行了研究.观察骨髓的C-中期细胞,结果证明牛蛙的体细胞染色体数目2n=26,其中有5对大型染色体和8对小型染色体,可以分成A、B、C 3个组,雌性和雄性个体间没有发现异型性染色体.上述结果与前人的研究结果基本一致.但是作者发现牛蛙骨髓细胞的第7、8、10、12号染色体上均有次缢痕.牛蛙的核型为2n=26=22m+4sm.

  6. Bullfrog tadpole (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) predation on early life stages of endangered razorback sucker (Xyrauchen texanus)

    Science.gov (United States)

    Mueller, G.A.; Carpenter, J.; Thornbrugh, D.

    2006-01-01

    Bullfrog tadpoles (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) are widespread introduced taxa that are problematic throughout the western United States. Their impact on native amphibians and crustaceans is well documented, but less is known regarding their influence on native fishes. Predator-prey tank tests showed both species consumed eggs and larvae of the endangered razorback sucker (Xyrauchen texanus) in a laboratory setting. Tadpoles consumed 2.2 razorback sucker eggs/d and 1.4 razorback sucker larvae/d, while crayfish ate 6.0 eggs/d and 3.5 larvae/d. Relatively high densities of bullfrog tadpoles and crayfish in razorback sucker spawning areas suggest that these nonnative taxa might pose a threat to the recruitment success of this and other imperiled native fish.

  7. Physiological features of the opercularis muscle and their effects on vibration sensitivity in the bullfrog Rana catesbeiana.

    Science.gov (United States)

    Hetherington, T E

    1987-09-01

    The amphibian opercularis muscle connects a movable otic element (the operculum) to the pectoral girdle and can act in reception of ground vibrations. Various physiological parameters of the opercularis muscle of the bullfrog Rana catesbeiana were measured and compared with similar measurements on the iliofibularis muscle of the hindlimb. The opercularis muscle is a very slowly contracting muscle, with a Vmax of 1.81 muscle lengths s-1 compared to a Vmax of 6.24 muscle lengths s-1 for the iliofibularis muscle. The opercularis muscle develops tension slowly, taking about 10 s to attain maximum isometric tension when stimulated at 100 Hz. The muscle can retain high levels of tension for several minutes, and following stimulation has a time to half-relaxation of about 4-6 s. The slow velocity of contraction, slow rate of tension development, fatigue-resistance and slow rate of relaxation of the opercularis muscle support morphological evidence that it consists mostly of tonic muscle fibres. Experiments were also made to examine the effects of muscle tension on reception of ground vibrations as measured by inner ear microphonics. Severing the nerve supplying the opercularis muscle produced slight decreases of no more than 2 dB in responses to vibrations from 25 to 200 Hz. Artificial stimulation of the opercularis muscle after severing the nerve supplying the muscle increased responses to vibration across the entire frequency range. Higher tension levels produced greater increases in responses; at the highest tensions used (about 120 kN m-2) responses were increased by as much as 4.5 dB. The opercularis muscle is therefore specialized for slow but prolonged contractions, and tension is important in its sensory function. A tensed opercularis muscle appears to transmit faithfully motion of the forelimb, produced by vibrations, to the operculum such that the latter moves relative to the inner ear fluids.

  8. Diet composition of post-metamorphic bullfrogs (Rana catesbeiana) in the Zhoushan archipelago,Zhejiang Province, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Bullfrogs (Runa catesbeiana) are listed as one of the 100 worst invasive alien species in the world.They are generalist predators and thus may affect native species through predation.In previous studies,the food contents of bullfrogs were mostly examined at a single site.In the present study,the diet composition of post-metamorphic bullfrogs on eight islands (Daishan,Liuheng,Xiushan,Fodu,Taohua,Xiashi,Cezi,and Putuoshan) in the Zhoushan Archipelago,Zhejiang Province of China,were examined by using the stomach flushing method from June 30 to August 11 in 2005.A total 0f391 individual frogs were measured,including 113 adults and 278 juveniles.The analysis of the stomach contents shows that,for adult bullfrogs,the most important prey (by diet volume) overall were Decapoda,Coleoptera,Odonata,Mesogastropoda,Raniformes,and Cypriniformes.For juvenile bullfrogs,these were Decapoda,Coleoptera,Cypriniformes,Odonata,Orthoptera,Hymenoptera,Lepidoptera larvae,Mesogastropoda,and Raniformes.Moreover,the prey size and diet volume increased with the body size of both adult and juvenile bullfrogs.The diet composition of primary preys of bullfrogs was significantly different among the islands.The results indicate that bullfrogs exert different predatory influences on native fauna at different sites and that bullfrogs are generalist predators with extensive ecological impacts on native fauna.

  9. Rana

    DEFF Research Database (Denmark)

    Jørgensen, Søren Vissing

    The aim of this work is the development of an open-source software tool, Rana, which enables real-time constrained simulation of multi-agent systems. Multi-agent systems research is a branch in the field of AI where focus is not on single agents, but rather on the emergent properties that arises...... from societies of agents. Rana represents the event driven simulation. This means that it has a focus on representation of perceivable agent actions, called events. The Rana event is a flexible information construct that can be set to propagate across the environment in simulated physical time. Rana......'s modelling paradigm offers flexible design of agent behaviour, which allows for separation of behavioural definitions for event handling and internal agent actions, both of which can be constrained by a real-time precision level. Each agent has a number af Rana specific modules at its disposal, these enable...

  10. Motor planning modulates sensory-motor control of collision avoidance behavior in the bullfrog, Rana catesbeiana

    Directory of Open Access Journals (Sweden)

    Hideki Nakagawa

    2012-08-01

    In this study, we examined the collision avoidance behavior of the frog, Rana catesbeiana to an approaching object in the upper visual field. The angular velocity of the frog's escape turn showed a significant positive correlation with the turn angle (r2 = 0.5741, P0.05. Thus, the frog was not able to control the velocity of the large escape turns accurately and did not complete the behavior within a constant time. In the latter case, there was a small but significant positive correlation between the threshold angular size and the angular velocity (r2 = 0.1459, P<0.05. This suggests that the threshold is controlled to compensate for the insufficient escape velocity achieved during large turn angles, and could explain a significant negative correlation between the turn angle and the threshold angular size (r2 = 0.1145, P<0.05. Thus, it is likely that the threshold angular size is also controlled by the turn angle and is modulated by motor planning.

  11. Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; Congdon, J.; Ray, J.K. [Savannah River Ecology Laboratory, Aiken, SC (USA)

    2000-04-01

    Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. The authors document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr and V, compared with others from the reference sites. In addition, malformed larvae from the most contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. It is hypothesized that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance.

  12. Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plant

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; Congdon, J.; Ray, J.K.

    2000-04-01

    Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. The authors document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr, and V, compared with conspecifics from the reference sites. In addition, malformed larvae from the cost contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. The authors hypothesize that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance.

  13. Climate change and American Bullfrog invasion: what could we expect in South America?

    Directory of Open Access Journals (Sweden)

    Javier Nori

    Full Text Available BACKGROUND: Biological invasion and climate change pose challenges to biodiversity conservation in the 21(st century. Invasive species modify ecosystem structure and functioning and climatic changes are likely to produce invasive species' range shifts pushing some populations into protected areas. The American Bullfrog (Lithobates catesbeianus is one of the hundred worst invasive species in the world. Native from the southeast of USA, it has colonized more than 75% of South America where it has been reported as a highly effective predator, competitor and vector of amphibian diseases. METHODOLOGY/PRINCIPAL FINDINGS: We modeled the potential distribution of the bullfrog in its native range based on different climate models and green-house gases emission scenarios, and projected the results onto South America for the years of 2050 and 2080. We also overlaid projected models onto the South American network of protected areas. Our results indicate a slight decrease in potential suitable area for bullfrog invasion, although protected areas will become more climatically suitable. Therefore, invasion of these sites is forecasted. CONCLUSION/SIGNIFICANCE: We provide new evidence supporting the vulnerability of the Atlantic Forest Biodiversity Hotspot to bullfrog invasion and call attention to optimal future climatic conditions of the Andean-Patagonian forest, eastern Paraguay, and northwestern Bolivia, where invasive populations have not been found yet. We recommend several management and policy strategies to control bullfrog invasion and argue that these would be possible if based on appropriate articulation among government agencies, NGOs, research institutions and civil society.

  14. Diet and Prey Selection of the Invasive American Bullfrog (Lithobates catesbeianus) in Southwestern China

    Institute of Scientific and Technical Information of China (English)

    Xuan LIU; Yu LUO; Jiaxin CHEN; Yisong GUO; Changming BAI; Yiming LI

    2015-01-01

    Invasive predators have been widely regarded as one of the principle drivers of the global decline of amphibians, which are among the most threatened vertebrate taxon on Earth. The American bullfrog (Lithobates catesbeianus) is identiifed as one of the most successful vertebrate invaders and has caused the decline or extinction of some native amphibians in many regions and countries including China. Based on ifeld surveys and stomach content analyses, we examined the diet composition of the invasive bullfrog for the ifrst time in two invaded populations in Yunnan Province, southwestern China, a region of global conservation priority, during the breeding season from 2008 to 2014. Additionally, we conducted the first quantitative study on the prey selection of this global invader among their invaded ranges after controlling for the local anuran assemblage and other aquatic preys in the environment. Our results showed that the range of food items in the stomachs of bullfrogs spanned more than 30 species belonging to ten taxonomic classes. Both of post-metamorphosis individuals and juveniles preyed upon native frogs, independent of the bullfrog’s body size and mouth width. Importantly, Jacobs’ selection index showed a bullfrog preference for the Yunnan pond frog (Babina pleuraden), one native endemic anuran with population decline, in terms of both food volume and occurrence. We therefore provided direct evidence on the predation impact of the invasive bullfrog on an endemic anuran and urged further efforts to prevent the dispersal of this invader into more fragile habitats to reduce their negative impacts on native amphibians.

  15. Estrogenic environmental contaminants alter the mRNA abundance profiles of genes involved in gonadal differentiation of the American bullfrog.

    Science.gov (United States)

    Wolff, Stephanie E; Veldhoen, Nik; Helbing, Caren C; Ramirez, Claire A; Malpas, Janae M; Propper, Catherine R

    2015-07-15

    Wildlife and human populations are exposed to anthropogenic mixtures of chemicals in the environment that may adversely influence normal reproductive function and development. We determined the effects of exposure to estrogenic chemicals and wastewater effluent (WWE) on developing gonads of the American bullfrog, Rana (Lithobates) catesbeiana, a species whose widespread distribution make it an ideal model for environmental monitoring of endocrine effects of chemical contaminants. Premetamorphic bullfrog tadpoles were exposed to treatment vehicle, 17β-estradiol (E2; 10(-9)M) or 4-tert-octylphenol (OP; 10(-9)M, 10(-8)M, and 10(-7)M). Additionally, gonadal differentiation was evaluated in bullfrog tadpoles from a WWE-containing site versus those from a reference location receiving no WWE. In both studies, phenotypic sex, steroidogenic factor-1 (nr5a1), and aromatase (cyp19a1) mRNA levels using quantitative real-time PCR were determined. Exposure to E2 or OP did not alter sex ratios. In controls, both nr5a1 and cyp19a1 transcript levels exhibited sexual dimorphism, with males demonstrating higher levels of nr5a1 and females greater abundance of cyp19a1. However, E2 exposure increased cyp19a1 mRNA abundance in testes and decreased levels in ovaries, eliminating the sexual dimorphism observed in controls. E2-exposed males exhibited increased nr5a1 transcript levels in the testes compared to controls, while females demonstrated no E2 effect. OP treatment had no effect on female cyp19a1 mRNA abundance, but exposure to 10(-7)M OP increased testicular transcript levels. Treatment with 10(-9) and 10(-8)M OP, but not 10(-7)M, resulted in decreased abundance of nr5a1 transcript in both ovaries and testes. Animals from the field had sexually dimorphic gonadal levels of cyp19a1, but both sexes from the WWE site exhibited elevated cyp19a1 transcript abundance compared to the reference location. Individual chemical compounds and anthropogenic wastewater effluent dispersed within

  16. Estrogenic environmental contaminants alter the mRNA abundance profiles of genes involved in gonadal differentiation of the American bullfrog

    Science.gov (United States)

    Wolff, Stephanie E.; Veldhoen, Nik; Helbing, Caren C.; Ramirez, Claire A.; Malpas, Janae M.; Propper, Catherine R.

    2015-01-01

    Wildlife and human populations are exposed to anthropogenic mixtures of chemicals in the environment that may adversely influence normal reproductive function and development. We determined the effects of exposure to estrogenic chemicals and wastewater effluent (WWE) on developing gonads of the American bullfrog, Rana (Lithobates) catesbeiana, a species whose widespread distribution make it an ideal model for environmental monitoring for endocrine effects of chemical contaminants. Premetamorphic bullfrog tadpoles were exposed to treatment vehicle, 17β-estradiol (E2; 10−9 M) or 4-tert-octylphenol (OP; 10−9 M, 10−8 M, and 10−7 M). Additionally, gonadal differentiation was evaluated in bullfrog tadpoles from a WWE-containing site versus those from a reference location receiving no WWE. In both studies, phenotypic sex, steroidogenic factor-1 (nr5a1), and aromatase (cyp19a1) mRNA levels using quantitative real-time PCR were determined. Exposure to E2 or OP did not alter sex ratios. In controls, both nr5a1 and cyp19a1 transcript levels exhibited sexual dimorphism, with males demonstrating higher levels of nr5a1 and females greater abundance of cyp19a1. However, E2 exposure increased cyp19a1 mRNA abundance in testes and decreased levels in ovaries, eliminating the sexual dimorphism observed in controls. E2-exposed males exhibited increased nr5a1 transcript levels in the testes compared to controls, while females demonstrated no E2 effect. OP treatment had no effect on female cyp19a1 mRNA abundance, but exposure to 10−7 M OP increased testicular transcript levels. Treatment with 10−9 and 10−8 M OP, but not 10−7 M, resulted in decreased abundance of nr5a1 transcript in both ovaries and testes. Animals from the field had sexually dimorphic gonadal levels of cyp19a1, but both sexes from the WWE site exhibited elevated cyp19a1 transcript abundance compared to the reference location. Individual chemical compounds and anthropogenic wastewater effluent dispersed

  17. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  18. Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity

    Directory of Open Access Journals (Sweden)

    CAMILA I. MEDEIROS

    2016-01-01

    Full Text Available ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.

  19. Effect of bullfrog (Rana catesbeiana oil administered by gavage on the fatty acid composition and oxidative stress of mouse liver

    Directory of Open Access Journals (Sweden)

    L.P. Silva

    2004-10-01

    Full Text Available The aim of the present study was to investigate the effects of daily intragastric administration of bullfrog oil (oleic, linoleic and palmitoleic acid-rich oil, corresponding to 0.4% of body weight for four weeks, on fatty acid composition and oxidative stress (lipid peroxidation and catalase activity in mouse liver. The activities of aspartate aminotransferase (AST, alkaline phosphatase (ALP, alanine aminotransferase (ALT, and gamma-glutamyltransferase (GGT, biomarkers of tissue injury, were determined in liver homogenates and serum. The proportions of 18:2n-6, 20:4n-6, 20:5n-3, and 22:6n-3 (polyunsaturated fatty acids, from 37 to 60% in the total fatty acid content were increased in the liver of the bullfrog oil-treated group (P < 0.05 compared to control. At the same time, a significant decrease in the relative abundance of 14:0, 16:0, and 18:0 (saturated fatty acids, from 49 to 25% was observed. The hepatic content of thiobarbituric acid reactive substances (TBARS was increased from 2.3 ± 0.2 to 12.3 ± 0.3 nmol TBA-MDA/mg protein and catalase activity was increased from 840 ± 32 to 1110 ± 45 µmol reduced H2O2 min-1 mg protein-1 in the treated group. Bullfrog oil administration increased AST and ALP activities in the liver (from 234.10 ± 0.12 to 342.84 ± 0.13 and 9.38 ± 0.60 to 20.06 ± 0.27 U/g, respectively and in serum (from 95.41 ± 6.13 to 120.32 ± 3.15 and 234.75 ± 11.5 to 254.41 ± 2.73 U/l, respectively, suggesting that this treatment induced tissue damage. ALT activity was increased from 287.28 ± 0.29 to 315.98 ± 0.34 U/g in the liver but remained unchanged in serum, whereas the GGT activity was not affected by bullfrog oil treatment. Therefore, despite the interesting modulation of fatty acids by bullfrog oil, a possible therapeutic use requires care since some adverse effects were observed in liver.

  20. Suplementação alimentar com vitamina C e desempenho zootécnico de girinos de rã-touro (Rana catesbeiana = Alimentary supplementation of Vitamin C and the performance indexes of bullfrog tadpoles (Rana catesbeiana

    Directory of Open Access Journals (Sweden)

    Neidison Carneiro Colombano

    2007-07-01

    Full Text Available Neste trabalho avaliou-se o desempenho zootécnico de girinos de rã-touro (Rana catesbeiana cuja dieta foi suplementada com vitamina C. Girinos com peso médio inicial de 12,3 mg ± 2 mg foram distribuídos em 16 caixas de água de 40 L, na densidade deum girino L-1. Os animais foram alimentados com dieta suplementada com zero (controle, 1.000, 1.500 e 2.000 mg de vitamina C kg-1 de ração, durante 75 dias. Após esse período foram avaliados quanto à sobrevivência, porcentagem de metamorfose, ganho de peso e taxade crescimento específico. As maiores taxas de sobrevivência (93%, porcentagem de metamorfose (29%, ganho de peso (4,22 g e taxa de crescimento específico (6,03% dia-1 foram dos animais que receberam 2.000 mg de vitamina C kg-1. O grupo não-suplementado foi o que apresentou o pior desempenho. Os resultados sugerem que a adição de 2.000 mg de vitamina C kg-1 produz efeitos benéficos para o ganho de peso, crescimento específico, metamorfose e sobrevivência de girinos de rã-touro.The present study had as objective to evaluate the effects of vitamin C supplementation on the performance indices of bullfrog (Rana catesbeiana tadpoles. The tadpoles, with an average weight of 12.3 ± 2 mg, were distributed in 16 boxes (40 L, with 1 tadpole L-1. They received diets supplemented with zero (control, 1,000, 1,500 and 2,000 mg of vitamin C kg-1 of diet, during 75 days. After this period, the survival, metamorphosis percentage, weight gain and specific growth rate were evaluated. The tadpoles that received 2,000 mg vitamin C kg-1 ration showed the best results in survival (93%, the best percentage of metamorphosis (29%, the greatest weight gain (4.22 g and the best specific growth rate (6.03% day-1. The worst performance was observed in the tadpoles that did not receive vitamin C. The results suggest that ration with 2,000 mg of vitamin C kg-1 improves weight gain, specific growth rate, metamorphosis andsurvival of the bullfrog tadpoles.

  1. Emerging Pathogen in Wild Amphibians and Frogs (Rana catesbeiana) Farmed for International Trade

    Science.gov (United States)

    Mazzoni, Rolando; Daszak, Peter; Apolo, Ada; Perdomo, Eugenio; Speranza, Gustavo

    2003-01-01

    Chytridiomycosis is an emerging disease responsible for global decline and extinction of amphibians. We report the causative agent, Batrachochytrium dendrobatidis, in North American bullfrogs (Rana catesbeiana) farmed for the international restaurant trade. Our findings suggest that international trade may play a key role in the global dissemination of this and other emerging infectious diseases in wildlife. PMID:12967500

  2. Efeito da densidade de estocagem no desempenho de rã-touro (Rana catesbeiana em recria Effects of stocking density on performance of bullfrog (Rana catesbeiana in the post-metamorphic phase

    Directory of Open Access Journals (Sweden)

    Alex Poeta Casali

    2005-12-01

    Full Text Available Este trabalho foi realizado com o objetivo de avaliar quatro densidades de estocagem na recria de rã-touro em mini-baias. As densidades estudadas foram: D1: 75 rãs/m² (inicial e 35 rãs/m² (final; D2: 105 rãs/m² (inicial e 50 rãs/m² (final; D3: 125 rãs/m² (inicial e 60 rãs/m² (final; e D4: 160 rãs/m² (inicial e 75 rãs/m² (final. No ensaio de desempenho, foram utilizadas 558 rãs com peso médio de 26,80 g durante 56 dias, distribuídas em um delineamento em blocos casualizados, com seis repetições. Houve efeito das densidades sobre o ganho de peso, que foram inversamente proporcionais. Menores densidades resultaram em maior consumo de alimento, de modo que, com o uso das densidades iniciais de 75 e 105 rãs/m², obteve-se maior consumo de alimento que o uso de 125 e 160 rãs/m². A conversão alimentar aparente também variou; a densidade inicial de 160 rãs/m² proporcionou a pior média desse parâmetro. Os tratamentos foram avaliados economicamente, segundo os custos com alimentação, a receita bruta e a receita líquida parcial proporcionados. Concluiu-se que a densidade final de 50 rãs/m² aumentou a receita líquida parcial, proporcionando resultados mais adequados para produção de rãs.This work was carried out with the objective of evaluate four stocking densities of bullfrog (post-metamorphic in mini-stalls. The densities studied were D1: 75 bullfrogs/m² (initial and 35 bullfrogs/m² (finishing; D2: 105 bullfrogs/m² (initial and 50 bullfrogs/m² (finishing; D3: 125 bullfrogs/m² (initial and 60 bullfrogs/m² (finishing; and D4: 160 bullfrogs/m² (initial and 75 bullfrogs/m² (finishing. The performance trial was carried out with 558 bullfrogs averaging initial weight of 26.80 g, during 56 days, according to a completely randomized blocks design with six replicates. Inversely proportional effects of densities on weight gain were observed. Smaller densities resulted in greater values of feed intake, and the initial

  3. Meal from tilapia filleting industrial waste in the feed of the bullfrog tadpoles (Rana Catesbeiana Shaw, 1802/ Inclusão de farinha de resíduos da indústria de filetagem de tilápias na alimentação de girinos de rã-touro (Rana Catesbeiana Shaw,1802

    Directory of Open Access Journals (Sweden)

    Cleiton Manske

    2007-08-01

    Full Text Available The objective of this experiment was to evaluate the inclusion of meal of tilapia industrial waster in bullfrog tadpoles’ diets (Rana Catesbeina Shaw, 1802. Two hundred fifty tadpoles with initial weight and length of 0,18 ± 0,05g and 2,50 ± 0,18 centimeters were used, respectively, they were used and distributed in 25 aquariums of 30 liter each in a complete randomized design with five treatments and five repetitions. The tadpoles were fed four times a day with diets containing 0, 5, 10 and 15% of inclusion of tilapia filleting and another diet with 0% of supplemented tilapia filleting with synthetic methionine, being supplied four times a day at ease. The experiment period was 30 days. The diets with tilapia filleting inclusion and methionine supplementation did not have influence in the final weight and length averages, feed survival and conversion of bullfrog tadpoles. It cam be used until 15% of tilapia filleting inclusion in the bullfrog tadpoles food. The synthetic methionine supplementation in diets for bullfrog tadpoles is not necessary in diets with levels over 0,47% of the total methionine.Este experimento objetivou avaliar a inclusão da farinha de resíduos de filetagem de tilápias (FT em rações para girinos de rã-touro (Rana Catesbeina Shaw,1802. Foram utilizados 250 girinos com peso e comprimento inicial de 0,18 ± 0,05g e 2,50 ± 0,18 cm, respectivamente, distribuídos em 25 aquários de 30 L cada, em um delineamento inteiramente casualizado com cinco tratamentos e cinco repetições. Os girinos foram alimentados quatro vezes ao dia, com rações contendo 0, 5, 10, 15% de inclusão de FT e outra ração com 0% de FT suplementada com metionina sintética, sendo fornecidas quatro vezes ao dia a vontade. O período do experimento foi de 30 dias. As rações com inclusão de FT e suplementação de metionina não influenciaram nas médias de peso final, comprimento final, sobrevivência e conversão alimentar dos girinos de r

  4. Relação de variáveis ambientais em baias cobertas com polietileno e desempenho da rã-touro (Rana catesbeiana Relationship between environmental variables in sheds covered with a polyethylene structure and the performance of bullfrogs (Rana catesbeiana

    Directory of Open Access Journals (Sweden)

    Sônia M. Teodoro

    2005-04-01

    Full Text Available Este trabalho visou a relacionar variáveis ambientais em instalação para criação de rãs, com cobertura de polietileno e baias construídas usando material alternativo, com o desempenho de rãs-touro (Rana catesbeiana. No interior das baias, foram medidas as temperaturas do piso, do ar ambiente (bulbo seco, de bulbo úmido, globo negro e da água do reservatório. Foram utilizados 60 animais por baia e três baias por galpão. As variáveis de desempenho estudadas foram peso vivo, ganho de peso e conversão alimentar. Nas condições experimentais, quando a temperatura do ar atingiu valores abaixo de 10 ºC ou superiores a 40 ºC, houve diminuição no consumo de ração pelos animais. Concluiu-se que o estresse predominante, neste tipo de estrutura, para as condições climáticas do período experimental, foi devido, principalmente, às baixas temperaturas. Concluiu-se, ainda, que o uso do Índice de Temperatura e Umidade (THI, na estimativa de variáveis de desempenho, melhorou a precisão da estimativa em relação ao uso exclusivo da temperatura do ar, embora valores desse índice, considerados estressantes para animais superiores, não o tenham sido para as rãs.The objective of this project was to find correlations between environmental variables of an installation used for raising frogs and the performance of the Bullfrog (Rana catesbeiana. Each installation included a shed built with alternative materials covered by a polyethylene structure. Floor, air (dry bulb, wet bulb, black globe and swimming water temperatures were measured inside the sheds. Sixty bullfrogs were raised in each shed with three sheds in each structure. The performance variables studied, included live weight, weight gain and food conversion. A decrease in food consumption was observed each time air temperatures fell below 10 ºC or went above 40 ºC. It was concluded that the main stress factor in this kind of structure and these climatic conditions during the

  5. Effect of Imidacloprid on the Erythrocyte of Bullfrog(Rana catesbeiana)%农药吡虫啉对牛蛙外周血红细胞的影响

    Institute of Scientific and Technical Information of China (English)

    潘海乙; 南旭阳; 陈院豪; 陈坤

    2013-01-01

      The pesticide(imidacloprid) solution was taken as the target poison and bullfrog(Rana catesbeiana) was taken as the experimental animal. The imidacloprid concentrations were set in the range from 0.005 g/L to 0.04 g/L. The effects of imidacloprid on the numbers,micronuclei rates,nuclear anomalies rates and total nuclear anomalies rates of erythrocyte in bullfrog were studied. The results showed that the imidacloprid could affect the numbers,micronuclei rates,nuclear anomalies rates and total nuclear anomalies rates of erythrocyte in bullfrog. When the concentration of imidacloprid was 0.04 g/L,the numbers of erythrocyte in the experimental groups (treated with imidacloprid) were lower than the number of erythrocyte in the contrast group. And there were significant difference between the experimental groups and contrast group(p<0.05 or p<0.01). When the concentration of imidacloprid ≥0.02 g/L,the micronuclei rates of erythrocyte in the experimental groups were higher than in the contrast group. And the difference between the experimental groups and contrast group were significant(p<0.05, p<0.01 or p<0.001). When the concentration of imidacloprid ≥0.01 g/L,the nuclear anomalies rates and total nuclear anomalies rates of erythrocyte in the experimental groups were higher than in the contrast group too. And there were significant difference between the experimental groups and contrast group(p<0.01 or p<0.001).%  以不同浓度的农药吡虫啉溶液为染毒药物,以牛蛙为实验对象,研究了牛蛙在0.005~0.04 g/L吡虫啉溶液的胁迫下,牛蛙外周血中血红细胞数、红细胞微核率、核异常率以及总核异常率的变化,以期发挥牛蛙在环境污染生物监测中的作用.结果表明:吡虫啉对牛蛙血红细胞数、红细胞微核率、核异常率以及总核异常率均有一定的影响.吡虫啉浓度为0.04 g/L时,染毒组的血红细胞数不仅低于对照组,而且达

  6. Could high salinity be used to control bullfrogs in small ponds?

    Science.gov (United States)

    Ward, David L.; Finch, Colton; Blasius, Heidi

    2015-01-01

    We examined survival of bullfrog (Rana catesbeiana) eggs and tadpoles at 3 ppt and 6 ppt salinity in the laboratory to determine if low-level salinity could be used to eradicate bullfrogs from small ponds that contain native fishes. Bullfrog eggs and tadpoles salinity for 10 days. Bullfrog tadpoles 10–15 days old experienced significantly reduced survival when exposed to salinity of 6 ppt for 10 days. Older bullfrog tadpoles (>9 months old) appeared unaffected by 14 days of 6 ppt salinity. Salinity of 3 ppt did not impact survival of bullfrog tadpole eggs or tadpoles at any of the life stages we tested. Adding salt to ponds in the early spring to increase salinity to 6 ppt may be a cost effective way to eradicate bullfrogs from small ponds without harming native fishes.

  7. Conboy Lake - Bullfrog and Bullhead Control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal is to support two AmeriCorps interns for 24 weeks to work on removal of American bullfrogs and brown bullhead to benefit Oregon spotted frogs, a...

  8. Multiple stressors in amphibian communities: Effects of chemical contamination, bullfrogs, and fish

    Science.gov (United States)

    Boone, M.D.; Semlitsch, R.D.; Little, E.E.; Doyle, M.C.

    2007-01-01

    A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted salamanders (Ambystoma maculatum) to overwintered bullfrog tadpoles (R. catesbeiana), bluegill sunfish (Lepomis macrochirus), the insecticide carbaryl, and ammonium nitrate fertilizer in 1000-L mesocosms. Most significantly, our study demonstrated that the presence of multiple factors reduced survival of B. americanus and A. maculatum and lengthened larval periods of R. sphenocephala. The presence of bluegill had the largest impact on the community; it eliminated B. americanus and A. maculatum and reduced the abundance of R. sphenocephala. Chemical contaminants had the second strongest effect on the community with the insecticide, reducing A. maculatum abundance by 50% and increasing the mass of anurans (frogs and toads) at metamorphosis; the fertilizer positively influenced time and mass at metamorphosis for both anurans and A. maculatum. Presence of overwintered bullfrogs reduced mass and increased time to metamorphosis of anurans. While both bluegill and overwintered bullfrog tadpoles had negative effects on the amphibian community, they performed better in the presence of one another and in contaminated habitats. Our results indicate that predicting deleterious combinations from single-factor effects may not be straightforward. Our research supports the hypothesis that combinations of factors can negatively impact some amphibian species and could contribute to population declines. ?? 2007 by the Ecological Society of America.

  9. Effects of Dietary Lipid Source and Emulsifier on Growth Performance, Intestinal Digestive Enzyme Activities and Hepatic Biochemical Indexes of Bullfrog, Rana (Lithobates) catesbeiana%饲料脂肪源和乳化剂对牛蛙生长性能、肠道消化酶活力及肝脏生化指标的影响

    Institute of Scientific and Technical Information of China (English)

    冯伟; 王玲; 张春晓; 宋凯; 张璐

    2015-01-01

    本试验旨在研究以猪油或鱼油为脂肪源的饲料中添加乳化剂对牛蛙生长性能、肠道消化酶活力及肝脏生化指标的影响。试验采用2×2因子完全随机区组试验设计,2种脂肪源(猪油和鱼油)和2个乳化剂添加水平(0和300 mg/kg),配成4种等氮等能的试验饲料。将初始平均体重为(19.01±0.01) g的180只牛蛙随机分为4组,每组3个重复,每个重复15只蛙,进行为期8周的饲养试验。结果表明:未添加乳化剂的鱼油组增重率( WGR)和摄食量( FI)显著高于未添加乳化剂的猪油组( P0.05)。添加乳化剂的鱼油组的各生长性能指标与未添加乳化剂的鱼油组均无显著差异(P>0.05)。各组牛蛙胴体水分、粗蛋白质、粗脂肪和粗灰分含量差异不显著(P>0.05),而添加乳化剂的猪油组全体粗脂肪含量显著高于未添加乳化剂的猪油组( P0.05),饲料中添加乳化剂显著提高以猪油为主要脂肪源牛蛙的肠道脂肪酶活力(P0.05)。各组牛蛙肝脏过氧化氢酶( CAT)和超氧化物歧化酶( SOD)活力无显著差异( P>0.05)。在以猪油为主要脂肪源时,添加乳化剂显著提高肝脏丙二醛( MDA)含量( P0.05)。根据结果得出,在以猪油为主要脂肪源的饲料中添加乳化剂可提高牛蛙的生长性能。%The objective of this study was to investigate the effects of using lard oil or fish oil as main lipid source supplemented with emulsifier on growth performance, intestinal digestive enzyme activities and hepatic biochemical indexes of bullfrog, Rana (Lithobates) catesbeiana. A randomized complete block design with 2× 2 factors was adopted in the experiment. Four iso-nitrogenous and iso-energetic diets were formulated with diet-ary lipid source including pork lard and fish oil, and the supplemental level of emulsifier was 0 and 300 mg/kg, respectively. One hundred and eighty bullfrogs with the initial average body weight of ( 19. 01 ± 0.01) g were randomly assigned to 4

  10. Ontogeny and distribution of cells in B lineage in the American leopard frog, Rana pipiens.

    Science.gov (United States)

    Zettergren, L D

    1982-01-01

    Two-color immunofluorescence techniques were used in order to trace the development and distribution of cells expressing immunoglobulin in Rana pipiens. Evidence is provided which suggests that (i) embryo-larval urogenital tissues are sites of generation of cells in B lineage, (ii) during ontogeny, there is a sequential expression of immunoglobulin isotypes on B cell surfaces, (iii) larvae are able to produce the full range of immunoglobulin clases found in adults, and (iv) at least two subpopulations of lymphocytes exist in Rana pipiens, sIg+ and sIg-; thymocytes and presumably peripheral T cells lack conventional surface immunoglobulin. Some ontogenetic and phylogenetic implications are discussed.

  11. 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...

  12. 饲料中添加胆汁酸对牛蛙生长性能、体组成和营养物质表观消化率的影响%EFFECTS OF DIETARY BILE ACID SUPPLEMENTATION ON THE GROWTH, WHOLE-BODY COMPOSITION AND APPARENT NUTRIENT DIGESTIBILITY OF BULLFROG (RANA CATESBEIANA)

    Institute of Scientific and Technical Information of China (English)

    胡田恩; 王玲; 张春晓; 宋凯; 李金宝

    2015-01-01

    To investigate the effects of dietary bile acids (BAs) on growth performance, body composition and apparent di-gestibility of dry matter, protein and lipid in diets for bullfrog,Rana catesbeiana,one hundred and forty-four bullfrogs were randomized to the same diet supplemented with four different levels of BAs (0, 100, 200, and 300 mg/kg). Compared with the control group, percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER) and nitrogen retention rate (NRR) of bullfrog were significantly higher at 200 mg/kg BAs-supplemented diet (P0.05). BAs did not significantly affect the contents of moisture, crude protein, crude ash in muscle and body of bullfrog, but it significantly decreased body lipid content without interfering muscle lipid content. No significant differences were found on the levels of triglycerides (TG), cholesterol (CHO), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) in serum cross groups (P>0.05). BAs diminished decreased blood urea nitrogen (BUN) concentration, and 300 mg/kg BAs-supplemented diet has the most dramatic effect. Serum glucose (GLU) concentration lowered significantly with decreasing dietary BAs from 0 mg/kg to 100 mg/kg, and then increased significantly (P0.05). Dietary BAs levels had no influence on the intestinal amylase activities. The highest dietary nutrient apparent digestibility coefficients (ADC) was observed in 200 mg/kg BAs-supplemented diet, and the lowestADC value was in the control group (P0.05)。200 mg/kg胆汁酸添加组牛蛙的增重率、特定生长率、饲料效率、蛋白质效率和氮保留率显著高于对照组(P0.05)。各处理组间血清总胆固醇、甘油三酯、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇浓度均无显著变化(P>0.05),血清尿素氮含量随着饲料中胆汁酸添加量的增加而降低,添加300 mg/kg胆汁酸组牛蛙血清尿素氮含量显著低于对照组(P0

  13. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil

    Science.gov (United States)

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F.; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A.; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H. B.

    2010-01-01

    Ranviruses (Iridoviridae) are increasingly associated with mortality events in amphibians, fish, and reptiles. They have been recently associated with mass mortality events in Brazilian farmed tadpoles of the American bullfrog Rana catesbeiana Shaw. 1802. The objectives of the present study were to further characterize the virus isolated from sick R. catesbeiana tadpoles and confirm the etiology in these outbreaks. Sick tadpoles were collected in 3 farms located in Goiás State, Brazil, from 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As for as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens. PMID:20066953

  14. Positive effects of nonnative invasive Phragmites australis on larval bullfrogs.

    Directory of Open Access Journals (Sweden)

    Mary Alta Rogalski

    Full Text Available BACKGROUND: Nonnative Phragmites australis (common reed is one of the most intensively researched and managed invasive plant species in the United States, yet as with many invasive species, our ability to predict, control or understand the consequences of invasions is limited. Rapid spread of dense Phragmites monocultures has prompted efforts to limit its expansion and remove existing stands. Motivation for large-scale Phragmites eradication programs includes purported negative impacts on native wildlife, a view based primarily on observational results. We took an experimental approach to test this assumption, estimating the effects of nonnative Phragmites australis on a native amphibian. METHODOLOGY/PRINCIPAL FINDINGS: Concurrent common garden and reciprocal transplant field experiments revealed consistently strong positive influences of Phragmites on Rana catesbeiana (North American bullfrog larval performance. Decomposing Phragmites litter appears to contribute to the effect. CONCLUSIONS/SIGNIFICANCE: Positive effects of Phragmites merit further research, particularly in regions where both Phragmites and R. catesbeiana are invasive. More broadly, the findings of this study reinforce the importance of experimental evaluations of the effects of biological invasion to make informed conservation and restoration decisions.

  15. Leukotriene C4 binds to receptors and has positive inotropic effects in bullfrog heart.

    Science.gov (United States)

    Chiono, M; Heller, R S; Andazola, J J; Herman, C A

    1991-03-01

    Leukotriene (LT) C4, LTD4 and LTE4 have positive inotropic effects on contractility of the isolated perfused bullfrog heart. The effects of LTD4 and LTE4 but not LTC4 can be blocked by the mammalian antagonist L-649,923. Characterization of specific binding sites for [3H]LTC4 on membrane preparations from American bullfrog (Rana catesbeiana) ventricle was carried out. Binding assays were done in the presence of serine (5 mM) and borate (10 mM) for 30 min at 23 degrees C. Under these conditions, no metabolism of LTC4 to LTD4 occurred. Specific binding of [3H]LTC4 reached steady state within 10 min, remained constant for 60 min, and was reversible with the addition of 1000-fold excess unlabeled LTC4. Scatchard analysis of the binding data indicated a single class of binding sites with a Kd of 33.9 nM and maximal binding capacity of 51.6 pmol/mg of protein. Competition binding studies revealed an order of potency of LTC4 greater than LTD4 greater than LTE4 with Ki values of 47, 11766 and 32248 nM, respectively. Glutathione and hematin had Ki values of 50566 and 6014 nM, respectively, suggesting that the LTC4 receptor is not a site on glutathione transferase. Two mammalian LTD4 antagonists, L-649,923 and LY171883 failed to inhibit specific binding of [3H]LTC4, suggesting that the LTC4 receptor is distinct from the LTD4 receptor. Guanosine-5'-O-3-thiotriphosphate did not affect specific binding of [3H]LTC4 indicating that, like mammalian LTC4 receptors, a Gi protein is not involved in the transduction mechanism. LTC4 acts on bullfrog hearts through specific membrane receptors and is similar to its mammalian counterpart.

  16. Tracking viral particles in the intestinal contents of the American bullfrog, Lithobates catesbeianus, by Transmission Electron Microscopy

    Directory of Open Access Journals (Sweden)

    A.M. Antonucci

    2014-04-01

    Full Text Available Feces are an important viral agent elimination route for infected carrier animals and in aquatic organisms these pathogenic agents can very rapidly propagate due to the habitation environment. The objective of this work is to track viral particles in the intestinal contents of bullfrogs (Lithobates catesbeianus from five commercial frog farms in the region of Vale do Paraíba, in the State of São Paulo, Brazil, using negative contrast transmission electron microscopy (TEM. The Coronaviridae, Paramyxoviridae, Parvoviridae and Herpesviridae families were observed and photographed in specimens. This work emphasizes the importance of adopting sanitary measures in commercial farms and confirms that observing feces by TEM is an efficient and rapid diagnostic tool for detecting viral agents.

  17. Stuttering: A novel bullfrog vocalization

    Science.gov (United States)

    Simmons, Andrea; Suggs, Dianne

    2004-05-01

    The advertisement call of male bullfrogs (Rana catesbeiana) consists of a series of individual croaks, each of which contains multiple harmonics with a missing or attenuated fundamental frequency of approximately 100 Hz. The envelope of individual croaks has typically been represented in the literature as smooth and unmodulated. From an analysis of 5251 advertisement calls from 17 different choruses over two mating seasons, we show that males add an extra modulation (around 4 Hz) to the envelope of individual croaks, following specific rules. We term these extra modulations stutters. Neither single croak calls nor the first croak in multiple croak calls contains stutters. When stuttering begins, it does so with a croak containing a single stutter, and the number of stutters increases linearly (plus or minus 1 stutter, up to 4 stutters) with the number of croaks. This pattern is stable across individual males (N=10). Playback experiments reveal that vocal responses to stuttered and nonstuttered calls vary with proximity to the stimulus. Close males respond with nonstuttered calls, while far males respond with stuttered calls. The data suggest that nonstuttered calls are used for aggressive or territorial purposes, while stuttered calls are used to attract females.

  18. THE EVOKED VOCAL RESPONSE OF THE BULLFROG; A STUDY OF COMMUNICATION BY SOUND.

    Science.gov (United States)

    The research attempts to bridge the existing gap between the naturalistic observations of sound communication in anurans and the anatomical and...principles by which information is processed within the intact animal. To this end, vocal behavior has been evoked from the males of laboratory colonies of...bullfrogs (Rana catesbeiana) in response to a restricted class of natural and synthetic sounds. The evoked vocal responses, having the signal

  19. Desempenho e parâmetros metabólicos de rã-touro, Rana catesbeiana, alimentada com diferentes rações comerciais - DOI: 10.4025/actascianimsci.v27i3.1214 Performance and metabolic parameters of the bullfrog, Rana catesbeiana, fed with different commercial rations - DOI: 10.4025/actascianimsci.v27i3.1214

    Directory of Open Access Journals (Sweden)

    Jaime Fenerick Junior

    2005-03-01

    Full Text Available O presente trabalho objetivou estudar o desenvolvimento da rã-touro alimentada com quatro rações comerciais (R1 = 42,36% e 4.143 Kcal/Kg; R2 = 41,36% e 4.467 Kcal/kg; R3 = 45,5% e 4.481 Kcal/Kg; R4 = 42,24% e 4.222 Kcal/Kg, respectivamente, de proteína bruta analisada e energia bruta calculada. A quantidade de seiscentas rãs com peso médio inicial variando de 12,6 g a 28 g foram utilizadas para avaliação do desempenho, glicemia, lipídio hepático, índice hepatossomático (IHS e índice gordurassomático (IGOS, em cinco coletas mensais. O pior desempenho foi observado em rãs alimentadas com a ração R4, apresentando menor ganho de peso e consumo de ração. Provavelmente, esse resultado foi devido ao menor consumo de ração observado e também à qualidade da proteína utilizada. Não foram observadas diferenças significativas entre as rações para conversão alimentar, lipídio hepático e IHS. Também foi observado um maior IGOS nas rãs que receberam R2, com tendência de aumento deste índice com o tempo em todos os tratamentosThis work evaluated the performance of the bullfrog, fed with four commercial rations (R1 = 42.36% and 4,143 Kcal/Kg; R2 = 41.36% and 4,467 Kcal/kg; R3 = 45.5% and 4,481 Kcal/Kg and R4 =42.24% and 4,222 Kcal/Kg respectively of analyzed crude protein and calculated crude energy. Six hundred bullfrogs with initial medium weight, varying from 12.6 to 28.0 g were used for evaluation of development, blood glucose, liver lipid, liver somatic index (LSI and fatty somatic index (FSI, in five monthly samples. The worst growth was observed in frogs fed with R4, presenting smaller weight gain and food consumption. Probably that result was due to the smallest ration consumption observed in this treatment and also quality of the used protein. No significant differences were observed among the rations for the food conversion, liver lipid and LSI. In addition, a larger FSI was observed in frogs that received R2, with a

  20. Attention to Invasive Risk of American Bullfrog for Hainan Island%警惕北美牛蛙入侵海南的风险

    Institute of Scientific and Technical Information of China (English)

    李闯; 王力军; 史海涛; 汪继超; 刘丹; 马凯

    2013-01-01

    Key words: The invasion of bullfrog (Lithobates catesbeianus) has become one of the main factors leading to native amphibian population decline and extinction. Bullfrog has distributed widely in China, but no any record in Hainan. In the duration of February to April in 2011, eight adult bullfrogs (including 1 pregnancy) were captured in three locations around Shazhou Island at Wanquan River, Hainan. The habitat bullfrogs were captured had the following characteristics; ① soil was mud or sand, ② distance from water about 0. 5 - 1. 5 m, ③ overall slope as 6° -25°, ④ vegetation coverage between 75% and 90% , and ⑤ native amphibian species were abundant around location. The bullfrog has been sold at local market and about 120 individuals were traded each day. Bullfrog found in Wanquan River may come from breeding escape or wildlife released by Buddhist. More survey is required to identify whether the breeding population has been built in the study area.%牛蛙(Lithobates catesbeianus)的入侵已成为本地两栖动物种群下降的主要因素之一,该物种在中国广泛分布,但在海南尚无分布记录.2011年2~4月,在海南省万泉河沙洲岛附近3个点捕捉到8只成体,其中1只个体已有卵.捕捉点的土壤基质为沙质或泥质,距水边距离0.5~1.5 m,整体坡度为6°~ 25°,植被盖度75% ~ 90%,生境附近本地两栖动物种类较为丰富.调查结果显示,市场上有牛蛙销售,销量约120只/d;琼海市有饲养牛蛙的记录,且存在粗放式(放养于田间)养殖情况,不排除养殖逃逸的可能;捕捉点附近有佛教组织定期放生,也存在个人放生行为.综合以上结果,万泉河发现牛蛙可能是养殖逃逸或放生所致,是否形成可繁殖的种群尚需进一步调查和研究.

  1. Histologia do rim, fígado e intestino de girinos de rã-touro (Rana catesbeiana alimentados com dietas contendo própolis Histology of kidney, liver and intestine of bullfrog tadpoles (Rana catesbeiana fed with diets containing propolis

    Directory of Open Access Journals (Sweden)

    Luis Ricardo Romero Arauco

    2007-10-01

    Full Text Available Este trabalho teve como objetivo verificar a ocorrência de possíveis alterações no fígado, rim e intestino de girinos de rã-touro no estágio 42, alimentados com dietas contendo diferentes concentrações (0,0; 0,2; 0,5; 1,0; e 1,5% de extrato hidroalcoólico de própolis. O experimento foi conduzido no laboratório de Nutrição de Organismos Aquáticos do Centro de Aqüicultura da UNESP, onde foram utilizados 1.400 girinos no estágio 26, distribuídos em vinte tanques experimentais. No final do experimento (60 dias, foram sacrificados três girinos de cada repetição e retiradas amostras de rim, fígado e intestino para processamento de lâminas histológicas no Laboratório de Histologia do Departamento de Morfologia e Fisiologia Animal da FCAV - UNESP. As amostras foram fixadas, desidratadas, coradas com HE, analisadas, fotomicrografadas e medida a espessura do epitélio intestinal. Não foram observadas alterações histológicas no intestino, rins e fígado dos girinos. A espessura do epitélio do intestino dos mesmos não foi influenciada (P>0,05 pelas concentrações de própolis.This research was aimed at verifying the occurrence of possible alterations in liver, kidney and intestine of bullfrog tadpoles in stage 42 fed with diets containing different concentrations (0.0; 0.2; 0.5; 1.0 and 1.5% of propolis hydroalcoholic extract. The experiment was carried out in laboratory of Aquatic Organisms Nutrition from Aquaculture Center of UNESP, where 1,400 tadpoles in stage 26 were used and distributed in twenty experimental aquariums. In the end of experiment (60 days three tadpoles from each repetition were sacrificed and kidney, liver and intestine samples were collected to processing of histological slices in Histology´s Laboratory pertaining to Department of Morphology and Physiology from FCAV - UNESP. Samples were fixed, dehydrated, stained in HE, analysed, photomicrographed and thickness of intestinal epithelium was measured

  2. Efeito do extrato hidroalcoólico de própolis no desempenho e na composição leucocitária do sangue de girinos de rã-touro (Rana catesbeiana = Propolis hidroalcoholic extract effect on performance and composition leucocytary of the blood bullfrog tadpoles (Rana catesbeiana

    Directory of Open Access Journals (Sweden)

    Luis Ricardo Romero Arauco

    2007-04-01

    Full Text Available Foi avaliado o efeito do extrato hidroalcoólico de própolis no desempenho e na composição leucocitária do sangue de girinos de rã-touro. Foram utilizados 1.400 girinos, distribuídos em vinte tanques experimentais com 70 litros de água, na densidade de umgirino por litro. Diferentes concentrações de própolis (0,0; 0,2; 0,5; 1 e 1,5% foram misturadas à ração comercial (45% Proteína Bruta. O arraçoamento foi realizado quatro vezes ao dia. No final do experimento, foi colhido sangue do vaso caudal de cinco girinos decada repetição. A contagem diferencial de leucócitos foi realizada em extensões coradas pelo método de Rosenfeld (1947, em microscopia de luz. A sobrevivência, o consumo de ração, a conversão alimentar e o comprimento dos girinos não foram influenciados pelo extratohidroalcoólico de própolis. O ganho de peso foi influenciado (p The effect of the propolis hidroalcoholic extract was evaluated on the performance of bullfrog tadpoles. 1,400 tadpoles were used, distributed in twenty experimental tanks with 70 liters of water, in the density of one tadpole per liter. The different levels of propolis (0.0; 0.2; 0.5; 1.0 and 1.5% were mixed with commercial ration (45% CP. The feeding was four times a day. In the end of the experiment, the blood was collected from the vase flow, in five tadpoles of each repetition. The differential counting of leucocytes was accomplished in red-faced extensions by the method of Rosenfeld (1947, in light microscope. The different levels of propolis hidroalcoholic extract did not influence the survival, consumption, feed conversion and length. Yet the weight gain suffered influence (p < 0.05 - it was observed a smaller weight gain in the tadpoles that did not receive propolis hidroalcoholic extract. The metamorphosis was more accelerated when they received propolis hidroalcoholic extract in their diet. The leucocytary group influenced by the propolis (p < 0.05 were the monocytes, which

  3. Efeito da temperatura e do fotoperíodo sobre o desenvolvimento do aparelho reprodutor de rã-touro (Rana catesbeiana Shaw, 1802 Effect of the temperature and the photoperiod on the development of bullfrog (Rana catesbeiana Shaw, 1802 reproduction apparel

    Directory of Open Access Journals (Sweden)

    Mario Roberto Chim Figueiredo

    2001-06-01

    combination of the temperatures of 26.0 and 29.0°C with photoperiods of 8/16, 12/12 and 16/8 h L/D, until they reach the gonadal maturity. Temperature interacted with photoperiod in its effects on the development of the reproductive organs of bullfrog. Temperature affected the diameter of the abdomen/distance relation between the eyes, with higher values calculated for 26°C. It was considered that the highest ovocites diameters are obtained under a temperature of 26.0°C, with photoperiod of 12.6/11.4 h L/D.

  4. Type I collagen from bullfrog (Rana catesbeiana) fallopian tube

    African Journals Online (AJOL)

    Jane

    2011-08-08

    Aug 8, 2011 ... African Journal of Biotechnology Vol. 10(42), pp. 8414-8420, 8 ... of animal origin. It has been utilized in food, cosmetics and biomedical ... CBB, coomassie brilliant blue R-250; FTIR, fourier transform infrared spectroscopy.

  5. Efeito do extrato hidroalcoólico de própolis no desempenho e na composição leucocitária do sangue de girinos de rã-touro (Rana catesbeiana - DOI: 10.4025/actascianimsci.v29i2.240 Propolis hidroalcoholic extract effect on performance and composition leucocytary of the blood bullfrog tadpoles (Rana catesbeiana - DOI: 10.4025/actascianimsci.v29i2.240

    Directory of Open Access Journals (Sweden)

    Laura Satiko Okada Nakaghi

    2007-11-01

    Full Text Available Foi avaliado o efeito do extrato hidroalcoólico de própolis no desempenho e na composição leucocitária do sangue de girinos de rã-touro. Foram utilizados 1.400 girinos, distribuídos em vinte tanques experimentais com 70 litros de água, na densidade de um girino por litro. Diferentes concentrações de própolis (0,0; 0,2; 0,5; 1 e 1,5% foram misturadas à ração comercial (45% Proteína Bruta. O arraçoamento foi realizado quatro vezes ao dia. No final do experimento, foi colhido sangue do vaso caudal de cinco girinos de cada repetição. A contagem diferencial de leucócitos foi realizada em extensões coradas pelo método de Rosenfeld (1947, em microscopia de luz. A sobrevivência, o consumo de ração, a conversão alimentar e o comprimento dos girinos não foram influenciados pelo extrato hidroalcoólico de própolis. O ganho de peso foi influenciado (p The effect of the propolis hidroalcoholic extract was evaluated on the performance of bullfrog tadpoles. 1,400 tadpoles were used, distributed in twenty experimental tanks with 70 liters of water, in the density of one tadpole per liter. The different levels of propolis (0.0; 0.2; 0.5; 1.0 and 1.5% were mixed with commercial ration (45% CP. The feeding was four times a day. In the end of the experiment, the blood was collected from the vase flow, in five tadpoles of each repetition. The differential counting of leucocytes was accomplished in red-faced extensions by the method of Rosenfeld (1947, in light microscope. The different levels of propolis hidroalcoholic extract did not influence the survival, consumption, feed conversion and length. Yet the weight gain suffered influence (p < 0.05 - it was observed a smaller weight gain in the tadpoles that did not receive propolis hidroalcoholic extract. The metamorphosis was more accelerated when they received propolis hidroalcoholic extract in their diet. The leucocytary group influenced by the propolis (p < 0.05 were the monocytes

  6. BULLFROG HEMOGRAM UNDER MANAGEMENT STRESS

    Directory of Open Access Journals (Sweden)

    Patrícia Coelho Teixeira

    2015-04-01

    Full Text Available Stress is one of the major obstacles in frog culture and can be caused by factors such as inappropriate farming systems; inadequate management among other situations. The objective of the present study was to assess the hemogram, erythrogram and leukogram of bullfrogs (L. catesbeianus when exposed to stress caused by different types of management: density and handling (manipulation, developed in the laboratory and repeated in the field for the appropriate comparisons in a experimental period of 30 days. The density experiment was conducted with four treatments: 70 animals m-2 (D70; 100 animals m-2 (D100, Control; 150 animals m-2 (D150 and 200 animals m-2 (D200, with 10, 14, 21 and 28 animals/box in the laboratory, respectively. Each treatment was performed with three simultaneous replicates. The handling experiment was conducted with three treatments: Treatment Without Handling (WH; Treatment with Partial Handling (PH every 15 days and Treatment with Total Handling (TH every 15 days. Each treatment was performed with four simultaneous replications. The methodology of the blood analysis followed international recommendations. In the present study we could observe that the animals of the field experiment did not reflect the same stress response observed in the laboratory in both experiment, which demonstrated the plasticity of these animals.

  7. PATHOLOGIC FINDINGS IN LARVAL AND JUVENILE ANURANS INHABITING FARM PONDS IN TENNESSEE, USA

    National Research Council Canada - National Science Library

    Miller, Debra L; Gray, Matthew J; Rajeev, Sreekumari; Schmutzer, A. Chandler; Burton, Elizabeth C; Merrill, Anita; Baldwin, Charles A

    2009-01-01

    .... During 2005, 104 American bullfrog (Rana catesbeiana) and 80 green frog (Rana clamitans) larvae and 40 green frog juveniles were collected from farm ponds in Tennessee, and complete necropsies were performed...

  8. De novo Transcriptome Assemblies of Rana (Lithobates catesbeiana and Xenopus laevis Tadpole Livers for Comparative Genomics without Reference Genomes.

    Directory of Open Access Journals (Sweden)

    Inanc Birol

    Full Text Available In this work we studied the liver transcriptomes of two frog species, the American bullfrog (Rana (Lithobates catesbeiana and the African clawed frog (Xenopus laevis. We used high throughput RNA sequencing (RNA-seq data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. We generated more than 1.5 billion RNA-seq reads in total for the two species under two conditions as treatment/control pairs. We de novo assembled these reads using Trans-ABySS to reconstruct reference transcriptomes, obtaining over 350,000 and 130,000 putative transcripts for R. catesbeiana and X. laevis, respectively. Using available genomics resources for X. laevis, we annotated over 97% of our X. laevis transcriptome contigs, demonstrating the utility and efficacy of our methodology. Leveraging this validated analysis pipeline, we also annotated the assembled R. catesbeiana transcriptome. We used the expression profiles of the annotated genes of the two species to examine the similarities and differences between the tadpole liver transcriptomes. We also compared the gene ontology terms of expressed genes to measure how the animals react to a challenge by thyroid hormone. Our study reports three main conclusions. First, de novo assembly of RNA-seq data is a powerful method for annotating and establishing transcriptomes of non-model organisms. Second, the liver transcriptomes of the two frog species, R. catesbeiana and X. laevis, show many common features, and the distribution of their gene ontology profiles are statistically indistinguishable. Third, although they broadly respond the same way to the presence of thyroid hormone in their environment, their receptor/signal transduction pathways display marked differences.

  9. A New Kind of Biomaterials-Bullfrog Skin Collagen

    Institute of Scientific and Technical Information of China (English)

    He LI; Bai Ling LIU; Hua Lin CHEN; Li Zhen GAO

    2003-01-01

    Pepsin-soluble collagen was prepared from bullfrog skin and partially characterized. This study revealed interesting differences, such as molecular weight, amino acid composition, denaturation temperature (Td), in the frog skin collagen when compared to the known vertebrate collagens. This study gives hints that bullfrog skin can be a potential, safe alternative source of collagen from cattle for use in various fields.

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

    Science.gov (United States)

    Bolek, Matthew G; Janovy, John

    2007-04-01

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

  11. Genetic reconstruction of a bullfrog invasion to elucidate vectors of introduction and secondary spread

    Science.gov (United States)

    Kamath, Pauline L.; Sepulveda, Adam; Layhee, Megan J.

    2016-01-01

    Reconstructing historical colonization pathways of an invasive species is critical for uncovering factors that determine invasion success and for designing management strategies. The American bullfrog (Lithobates catesbeianus) is endemic to eastern North America, but now has a global distribution and is considered to be one of the worst invaders in the world. In Montana, several introduced populations have been reported, but little is known of their sources and vectors of introduction and secondary spread. We evaluated the genetic composition of introduced populations at local (Yellowstone River floodplain) and regional (Montana and Wyoming) scales in contrast to native range populations. Our objectives were to (1) estimate the number of introductions, (2) identify probable native sources, (3) evaluate genetic variation relative to sources, and (4) characterize properties of local- and regional-scale spread. We sequenced 937 bp of the mitochondrial cytochrome b locus in 395 tadpoles collected along 100 km of the Yellowstone River, from three additional sites in MT and a proximate site in WY. Pairwise ΦST revealed high divergence among nonnative populations, suggesting at least four independent introductions into MT from diverse sources. Three cyt b haplotypes were identical to native haplotypes distributed across the Midwest and Great Lakes regions, and AMOVA confirmed the western native region as a likely source. While haplotype (Hd = 0.69) and nucleotide diversity (π = 0.005) were low in introduced bullfrogs, the levels of diversity did not differ significantly from source populations. In the Yellowstone, two identified haplotypes implied few introduction vectors and a significant relationship between genetic and river distance was found. Evidence for multiple invasions and lack of subsequent regional spread emphasizes the importance of enforcing legislation prohibiting bullfrog importation and the need for continuing public education to prevent

  12. Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

    Science.gov (United States)

    Germaine, S.S.; Hays, D.W.

    2009-01-01

    Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002-2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.

  13. Identification of organ-autonomous constituents of the molecular memory conferred by thyroid hormone exposure in cold temperature-arrested metamorphosing Rana (Lithobates) catesbeiana tadpoles.

    Science.gov (United States)

    Austin Hammond, S; Jackman, Kevin W; Partovi, Shireen H; Veldhoen, Nik; Helbing, Caren C

    2016-03-01

    Environmental temperature modulates thyroid hormone (TH)-dependent metamorphosis in some amphibian species. The North American bullfrog--Rana (Lithobates) catesbeiana - tadpole is naturally adapted to a wide range of temperatures over multiple seasons. Cold temperatures delay while warmer temperatures accelerate metamorphosis. Exogenous TH exposure of premetamorphic tadpoles results in a rapid precocious induction of metamorphosis at warm temperatures (20-25 °C). The same exposure at cold temperatures (4-5 °C) does not elicit an overt metamorphic response. However, a molecular memory of TH exposure is established such that cold, TH-exposed tadpoles returned to permissive warm temperatures will rapidly execute TH-induced genetic programs. Previous mRNA profiling has identified TH-regulated transcription factors encoded by thra, thrb, thibz, klf9, and cebp1 as components of the molecular memory after one week post-exposure. However, a further hierarchy may exist within the initiation phase since many gene transcripts demonstrated tissue-specific patterns. Whether the molecular memory is organ autonomous or requires additional modulating factors is unknown. Herein we examine tail fin and back skin and determine that thibz is the only transcript that is TH-responsive after 2 days post-exposure at low temperature in both tissues in the intact animal. In back skin, cebp1 is also TH-responsive under these conditions. Serum-free tail fin organ culture (C-Fin) reveals that the thibz response is organ autonomous whereas cultured back skin (C-Skin) results suggest that thibz and cebp1 require an additional factor for induction from elsewhere within the intact animal. Subsequent investigations are now possible to identify endogenous factors that modulate the molecular memory in intact animals.

  14. Complete mitochondrial genomes of two brown frogs, Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae).

    Science.gov (United States)

    Li, Jiao; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

    We first determined complete mitochondrial genomes of Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae). The mitogenomic lengths of R. dybowskii and R. cf. chensinensis were 18,864 and 18,808 bp, respectively. The two mitogenomes have similar gene compositions including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region. Rana dybowskii and R. cf. chensinensis mitogenomes displayed same gene order arrangements and similar base compositions with an A + T bias. Mitogenomic data of the two species contributed to provide molecular marker for their conservative genetics and clarified their phylogenetic position under mitogenome-based phylogeny of the genus Rana.

  15. Basolateral Cl- channels in the larval bullfrog skin epithelium

    DEFF Research Database (Denmark)

    Hillyard, Stanley D.; Rios, K.; Larsen, Erik Hviid

    2002-01-01

    The addition of 150 U/ml nystatin to the mucosal surface of isolated skin from larval bullfrogs increases apical membrane permeability and allows a voltage clamp to be applied to the basolateral membrane. With identical Ringer's solutions bathing either side of the tissue the short-circuit current...

  16. Energetics of coupled Na+ and Cl- entry into epithelial cells of bullfrog small intestine.

    Science.gov (United States)

    Armstrong, W M; Bixenman, W R; Frey, K F; Garcia-Diaz, J F; O'Regan, M G; Owens, J L

    1979-02-20

    Na+, K+ and Cl- concentrations (cij) and activities (aij), and mucosal membrane potentials (Em) were measured in epithelial cells of isolated bullfrog (Rana catesbeiana) small intestine. Segments of intestine were stripped of their external muscle layers, and bathed (at 25 degrees C and pH 7.2) in oxygenated Ringer solutions containing 105 mM Na+ and Cl- and 5.4 mM K+. Na+ and K+ concentrations were determined by atomic absorption spectrometry and Cl- concentrations by conductometric titration following extraction of the dried tissue with 0.1 M HNO3. 14C-labelled inulin was used to determine extracellular volume. Em was measured with conventional open tip microelectrodes, aiCl with solid-state Cl-selective silver microelectrodes and aiNa and aiK with Na+ and K+-selective liquid ion-exchanger microelectrodes. The average Em recorded was -34mV. ciNa, ciK and ciCl were 51, 105 and 52 mM. The corresponding values for aiNa, aiK and aiCl were 18, 80 and 33 mM. These results suggest that a large fraction of the cytoplasmic Na+ is 'bound' or sequestered in an osmotically inactive form, that all, or virtually all the cytoplasmic K+ behaves as if in free solution, and that there is probably some binding of cytoplasmic Cl-. aiCl significantly exceeds the level corresponding to electrochemical equilibrium across the mucosal and baso-lateral cell membranes. Earlier studies showed that coupled mucosal entry of Na+ and Cl- is implicated in intracellular Cl- accumulation in this tissue. This study permitted estimation of the steady-state transapical Na+ and Cl- electrochemical potential differences (deltamuNa and deltamuCl). deltamuNa (-7000 J . mol-1; cell minus mucosal medium) was energetically more than sufficient to account for deltamuCl (1000--2000 J . mol-1).

  17. Pesticide Distributions and Population Declines of California Alpine Frogs, Rana Muscosa and Rana Sierrae

    Science.gov (United States)

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in th...

  18. Pesticide Distributions and Population Declines of California Alpine Frogs, Rana Muscosa and Rana Sierrae

    Science.gov (United States)

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in th...

  19. Stretch-activated cation channel from larval bullfrog skin.

    Science.gov (United States)

    Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

    2010-05-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed a variable pattern of opening and closing with continuing suction. Current-voltage plots demonstrated linear or inward rectification and single channel conductances of 44-56 pS with NaCl or KCl Ringer's solution as the pipette solution, and a reversal potential (-V(p)) of 20-40 mV. The conductance was markedly reduced with N-methyl-D-glucamide (NMDG)-Cl Ringer's solution in the pipette. Neither amiloride nor ATP, which are known to stimulate an apical cation channel in Ussing chamber preparations of larval frog skin, produced channel activation nor did these compounds affect the response to suction. Stretch activation was not affected by varying the pipette concentrations of Ca(2+) between 0 mmol l(-1) and 4 mmol l(-1) or by varying pH between 6.8 and 8.0. However, conductance was reduced with 4 mmol l(-1) Ca(2+). Western blot analysis of membrane homogenates from larval bullfrog and larval toad skin identified proteins that were immunoreactive with mammalian TRPC1 and TRPC5 (TRPC, canonical transient receptor potential channel) antibodies while homogenates of skin from newly metamorphosed bullfrogs were positive for TRPC1 and TRPC3/6/7 antibodies. The electrophysiological response of larval bullfrog skin resembles that of a stretch-activated cation channel characterized in Xenopus oocytes and proposed to be TRPC1. These results indicate this channel persists in all life stages of anurans and that TRP isoforms may be important for sensory functions of their skin.

  20. Duration of spermatogenesis in the bullfrog (Lithobates catesbeianus).

    Science.gov (United States)

    Segatelli, T M; Batlouni, S R; França, L R

    2009-10-15

    The bullfrog (Lithobates catesbeianus) has substantial economic importance and has also been used as an experimental model for biological studies in the fields of pharmacology, medicine, and reproductive biology, especially studies addressing gametogenesis. However, there is a lack of comprehensive information in the literature regarding testis structure and function in this amphibian. The main objective of the current study was to estimate the duration of the various phases of spermatogenesis in this vertebrate. Sixteen sexually mature bullfrogs received an intracoelomic administration of tritiated thymidine. Testes were analyzed at various times between 1h and 33 d after administration to detect the most advanced germ cell types labeled at each interval, as well as labeled preleptotene spermatocytes, which presumably originated from spermatogonial stem cells. The duration of the spermatogonial, spermatocytic, and spermiogenic phases of spermatogenesis in the bullfrog were approximately 18, 14, and 8 d, respectively. Thus, the total duration of the spermatogenesis process from early spermatogonia through to spermatozoa was 40 d in this species, similar to that of most previously investigated mammalian species. To our knowledge, this is the first reliable report on the duration of the full spermatogenic process in any amphibian species. These findings will be very useful for tracking the pace of germ cells in studies involving spermatogonial transplantation in lower vertebrates.

  1. Carcass yield and proximate composition of bullfrog (Lithobates catesbeianus

    Directory of Open Access Journals (Sweden)

    Athos Alexandre Cesnik Ayres

    2015-10-01

    Full Text Available This work evaluated five classes of weight of bullfrog (Lithobates catesbeianus seeking to define the ideal slaughter weight for the species. We used 79 bullfrogs, distributed in a completely randomized design (class 1 251 g (n = 14, which were euthanized, weighted and gutted. For the carcass yield, we weighed the clean torso, thighs, liver, skin and head. The clean torso was subjected to chemical composition analysis. The carcass yield was, on average, 49% with no difference between weight classes (p > 0.05. The yield of posterior thighs was significantly higher for the lower weight class, which also presented higher percentage of paws (28.37 ± 0.63 and 9.33 ± 0.21, respectively (p < 0.05. The percentages of visceral fat and skin showed a progressive increase along with the weight of the animals; the class with individuals weighing 201-250 grams showed the higher values (p < 0.05. The chemical composition indicated that individuals above 251 grams showed lower values of ether extract and higher values of crude protein (0.99 ± 0.14and 15.80 ± 0.64, respectively (p < 0.05. So, it is recommended the slaughter of bullfrogs weighing more than 201 grams, because of better yield and meat quality.

  2. Antibiogram and heavy metal tolerance of bullfrog bacteria in Malaysia

    Directory of Open Access Journals (Sweden)

    M. Najiah

    2011-10-01

    Full Text Available Bacterial isolates from 30 farmed bullfrogs (Lithobates catesbeianus weighing 500-600 g at Johore, Malaysia with external clinical signs of ulcer, red leg and torticollis were tested for their antibiograms and heavy metal tolerance patterns. A total of 17 bacterial species with 77 strains were successfully isolated and assigned to 21 antibiotics and 4 types of heavy metal (Hg2+, Cr6+, Cd2+, Cu2+. Results revealed that bacteria were resistant against lincomycin (92%, oleandomycin (72.7% and furazolidone (71.4% while being susceptible to chloramphenicol and florfenicol at 97.4%. The multiple antibiotic resistance (MAR index for C. freundii, E. coli and M. morganii was high with the value up to 0.71. Bacterial strains were found to exhibit 100 % resistance to chromium and mercury. High correlation of resistance against both antibiotics and heavy metals was found (71.4 to 100% between bullfrog bacteria isolates, except bacteria that were resistant to kanamycin showed only 25% resistance against Cu2+. Based on the results in this study, bacterial pathogens of bullfrog culture in Johore, Malaysia, were highly resistant to both antibiotics and heavy metals.

  3. Gastrin and Cholecystokinin of the Bullfrog, Rana catesbeiana, Have Distinct Effects on Gallbladder Motility and Gastric Acid Secretion in Vitro

    DEFF Research Database (Denmark)

    Nielsen, Kaj; Bomgren, Peter; Holmgren, Susanne;

    1998-01-01

    values are 3.1 and 17.2 nM, respectively. Furthermore, gastrin had a significantly higher efficacy than CCK-8s. Thus, in spite of their close structural resemblance, there are clear differences between the two endogenous peptides in their action on gallbladder and gastric mucosa. It is concluded...

  4. Bioconversion of leukotriene C4 by the bullfrog heart.

    Science.gov (United States)

    Herman, R P; Heller, R S; Canavan, C M; Herman, C A

    1988-01-01

    Isolated perfused bullfrog hearts were administered randomized doses of LTC4, LTD4 or LTE4. The cardiac parameters of heart rate, developed tension and its first derivative (dT/dt) were recorded. LTC4 was the most potent of the leukotrienes tested in eliciting positive inotropic effects. LTD4 and LTE4 were equally effective but about one order of magnitude less potent than LTC4. None of the LTs showed any chronotropic effects in this preparation. LTC4 was significantly more potent in the presence of L-serine borate, an inhibitor of gamma-glutamyl transpeptidase, than in its absence, raising the possibility of significant bioconversion of LTC4 by the bullfrog heart. 3H-LTC4 metabolism experiments were carried out using whole perfused hearts or minced bullfrog heart tissue. During the six minute course of collection, the isolated perfused heart converted significant amounts of LTC4 to LTD4 and to a lesser degree LTE4. This conversion was attenuated in the presence of L-serine borate. Both minced atrial and ventricular tissue converted 3H-LTC4 to radioactive metabolites which co-migrated with authentic LTD4 and LTE4 standards. In both tissues, the major product was LTD4, with smaller amounts of LTE4 produced. The atrium converted significantly more LTC4 to its metabolites than did the ventricle. The metabolism of LTC4 to LTD4 by both tissues was virtually abolished in the presence of serine borate. It is interesting that LTC4 metabolism pattern and rate is comparable in mammals and frogs in spite of the fact that the inotropic effects of leukotrienes are opposite in the two taxa and, in frogs, metabolism results in a less potent agent.

  5. Stretch-activated cation channel from larval bullfrog skin

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

    2010-01-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed...... was markedly reduced with N-methyl-D-glucamide (NMDG)-Cl Ringer's solution in the pipette. Neither amiloride nor ATP, which are known to stimulate an apical cation channel in Ussing chamber preparations of larval frog skin, produced channel activation nor did these compounds affect the response to suction....... Stretch activation was not affected by varying the pipette concentrations of Ca(2+) between 0 mmol l(-1) and 4 mmol l(-1) or by varying pH between 6.8 and 8.0. However, conductance was reduced with 4 mmol l(-1) Ca(2+). Western blot analysis of membrane homogenates from larval bullfrog and larval toad skin...

  6. Control of lung ventilation following overwintering conditions in bullfrogs, Lithobates catesbeianus

    National Research Council Canada - National Science Library

    Santin, Joseph M; Hartzler, Lynn K

    2016-01-01

    ... that regulate and enable pulmonary ventilation. Therefore, we performed experiments to determine whether aspects of the respiratory control system of bullfrogs, Lithobates catesbeianus, are maintained or suppressed following minimal use of air...

  7. Status of bullfrogs and northern leopard frogs at Fish Springs National Wildlife Refuge, Juab County, Utah

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document describes aspects of the ecology and natural history of bullfrogs introduced to Fish Springs National Wildlife Refuge. The purpose of this study was to...

  8. Enzymatic activity of lipase in post-metamorphic phase bullfrogs Atividade enzimática da lipase em rã-touro na fase pós-metamórfica

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Tavares Braga

    2006-10-01

    Full Text Available The knowledge of the digestive system of bullfrogs is an important step for the determination of their nutritional requirements throughout growth phases. With the objective of evaluating the enzymatic activity of lipase in the intestinal content of bullfrogs (Rana catesbeiana Shaw, 1802, 100 animals with median weight of 3.6 g were distributed in stalls under controlled temperature and photoperiod. The frogs, selected at the post-metamorphic phase, received commercial extruded diet ad libitum throughout the 87-day experiment. The collections of the intestinal content were performed by the desensitization of the frogs in ice and water at 0ºC and subsequent isolation of the small intestine. Determination of lipase activity was performed with a commercial enzymatic kit (Lipase-Bioclin, MG, Brazil, first measured in samples taken at day three (3.46 UI. During the initial phase the bullfrog possesses low lipase hydrolysis capacity was found, having a specific activity of 217 UI mg-1. In the subsequent period both lipase activity and specific lipase activity continuously increased. Lipase activity as a function of bullfrog weight fell after day twenty and reached 0.33 UI g-1, for frogs of medium weight (179 g. Feed for bullfrogs at the post-metamorphic phase weighing more than 10 g can have larger amounts of ingredients containg lipids, due to the increased digestive capacity of these frogs.O conhecimento do sistema digestório da rã-touro é um passo importante para a determinação de sua exigência nutricional nas diferentes fases de crescimento. Com o objetivo de avaliar a atividade enzimática da lipase no conteúdo intestinal da rã-touro (Rana catesbeiana Shaw, 1802, 100 animais com peso médio de 3,6 g foram distribuídos em baias-teste com temperatura e fotoperíodo controlados. As rãs, selecionadas na fase pos-metamórfica receberam ração extruzada comercial ad libitum. Durante 87 dias de experimento, 29 coletas (87 rãs foram feitas em

  9. Histological Study on Reproductive Organ of Rana Temporaria Chensinesis David

    Institute of Scientific and Technical Information of China (English)

    HUANG He; TIAN Yaguang; NING Fangyong; BAI Xiujuan; ZHANG Guixue

    2006-01-01

    The experiment was designed to study the histology of reproductive organ of Rana temporaria chensinesis David in reproductive season and dereproductive season, The results displayed that the sexual gland weight and oviduct weight of the Rana temporaria chensinesis David were significantly different between reproductive season and dereproductive season.

  10. Blood and urine physiological values in farm-cultured Rana catesbeiana (Anura: Ranidae) in Argentina.

    Science.gov (United States)

    Coppo, José A; Mussart, Norma B; Fioranelli, Santiago A

    2005-01-01

    A total of 302 samples of healthy farm-cultured Rana catesbeiana specimens (9-21 months-old, 50-350 g liveweight, 50% each sex) from the north-east of Argentina, were analyzed through spectrophotometry, electrophoresis, densitometry, refractometry and microscopy in order to obtain blood and urine normal values. Confidence intervals (pratio (0.50-0.58), creatinine (4.09-5.56 mg/L). urea (76.1-92.4 mg/L), uric acid (11.5-15.4 mg/L), triglycerides (0.34-0.52 g/L), total cholesterol (0.56-0.67 g/L), HDL-C (0.03-0.05 g/L), LDL-C (0.34-0.44 g/L), alpha lipoprotein (6.01-8.67%). beta lipoprotein (91.3-93.9%), glucose (0.45-0.54 g/L), Na (116-121 meq/L), K (3.42-3.81 meq/L), Cl (100-116 meq/L), Ca (7.98-8.61 mg/dL). P (8.319.36 mg/dL), Mg (2.26-2.55 mg/dL), Fe (105-178 ug/dL), ALP (144-170 [U/L), ALT (10.0-14.8 IU/L), AST (42.8-53.4 IU/L), GGT (7.8-10.6 IU/L), LDH (99-135 IU/L), CHE (151-185 lU/L) and CPK (365-500 IU/L), were obtained. Some parameter ranges were similar to those obtained in amphibians, birds or mammals; others were very different. These parameters are useful to evaluate sanitary, metabolic and nutritional state on captive bullfrogs.

  11. Introduced bullfrogs and their parasites: Haematoloechus longiplexus (Trematoda) exploits diverse damselfly intermediate hosts on Vancouver Island.

    Science.gov (United States)

    Novak, Colin W; Goater, Timothy M

    2013-02-01

    The lung fluke, Haematoloechus longiplexus, is the most prevalent and abundant parasite of introduced bullfrogs on Vancouver Island, British Columbia, Canada. The ecological success of this trematode in invasive bullfrogs is related to the fluke's ability to utilize native intermediate hosts for transmission. The purpose of this study was to identify the odonate (dragonfly/damselfly) species involved in the transmission of H. longiplexus to the introduced bullfrog. The prevalences and mean intensities of 21 species of odonates (nymphs and adults) were examined for metacercariae infections. Haematoloechus longiplexus is a second intermediate host specialist, being found only in damselflies. Six damselfly species exhibiting the "climber" ecological habit were identified as second intermediate hosts of H. longiplexus. Enallagma carunculatum (prevalence = 75.0%, mean intensity = 17.2 ± 10.8), Ischnura cervula (65.2%, 8.9 ± 4.3), Ischnura perparva (45.5%, 15.4 ± 10.3), and Enallagma boreale (40.7%, 4.8 ± 7.8) were the most commonly infected damselfly species. Metacercariae were absent in damselflies collected from sites lacking bullfrogs. Haematoloechus longiplexus was likely introduced along with the bullfrog, and subsequently adapted to the physid snail and diverse damselfly intermediate hosts present in ponds on Vancouver Island.

  12. La introducción y el cultivo de la rana toro (Rana catesbeiana. ¿Un atentado a la biodiversidad de México?

    Directory of Open Access Journals (Sweden)

    Gustavo Casas Andreu

    2001-01-01

    Full Text Available Se analiza el efecto que la introducción y el cultivo de la rana toro (Rana catesbeiana ha tenido en el ecosistema y la biodiversidad en México. Se recomienda el cultivo de especies nativas para sustituir a la rana toro.

  13. Redescription of the Frog Bladder Fluke Gorgoderina attenuata from the Northern Leopard Frog, Rana pipiens

    National Research Council Canada - National Science Library

    Matthew G. Bolek; Scott D. Snyder; John Janovy Jr

    2009-01-01

    .... Morphological comparisons between gravid G. attenuata recovered from bullfrogs and northern leopard frogs indicated statistically significant differences in 11 of 28 morphological characters examined...

  14. Cadmium block of isometric contractions of isolated bullfrog atrial cells.

    Science.gov (United States)

    Shepherd, N; Kavaler, F; Spielman, W

    1991-02-01

    We studied the effect of cadmium, verapamil, and quinacrine on the force of contraction (Fp) of isolated, single, field-stimulated bullfrog atrial cells. All agents were applied or removed rapidly (t1/2 approximately 15 ms) to minimize intracellular concentration changes other than intracellular calcium concentration. Two components of twitch force were observed, one blocked by micromolar Cd2+ and the other by millimolar Cd2+. The two contributed about equally to the activation of the twitch. The "cadmium-sensitive" portion of force (that affected by [Cd] less than or equal to 100 microM) had a K1/2 approximately 1 microM, was identical in magnitude to, and not additive with, a "verapamil-sensitive" (10 microM) component of force, was most strongly affected by 50-ms pulses of Cd2+ when they were applied in the mechanical latent period, and was potentiated by catecholamines. The cadmium-insensitive portion of force was abolished by the removal of extracellular calcium and was greatly potentiated by quinacrine (3 or 10 microM), a blocker of Na-Ca exchange. The results are consistent with the idea that activating calcium enters the cell via both an inactivating cadmium-sensitive L-type channel and a noninactivating cadmium-insensitive mechanism that is not Na-Ca exchange and leaves the cell via Na-Ca exchange.

  15. Final Critical Habitat for Oregon Spotted Frog (Rana pretiosa)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of FINAL critical habitat for Rana pretiosa (Oregon Spotted Frog). Maps published in the Federal Register 2016.

  16. Final Critical Habitat for Oregon Spotted Frog (Rana pretiosa)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of FINAL critical habitat for Rana pretiosa (Oregon Spotted Frog). Maps published in the Federal Register 2016.

  17. Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from mark-recapture surveys conducted in 2015 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort...

  18. Helminths of the two mountain frogs, banded frog, Rana camerani Boulenger, 1886 and Uludağ frog Rana macrocnemis Boulenger, 1885 (Anura: Ranidae), collected from the Antalya province.

    Science.gov (United States)

    Düşen, Serdar

    2007-01-01

    In this study, two mountain frogs (Rana camerani and Rana macrocnemis) were collected in the Antalya Province in south-western Turkey during 2001 and 2002 and were examined for helminths. Out of 15 Rana camerani, 10 (66.7%) were infected with 1 or more helminths and out of 20 Rana macrocnemis, 17 (85%) were infected with 1 or more helminths. The helminth fauna of Rana camerani included 4 species of which were 3 trematode species (Haplometra cylindracea, Pleurogenoides medians, Opisthioglyphe rastellus), and 1 nematode species (Cosmocerca ornata). The helminth fauna of Rana macrocnemis included 3 species with 1 trematode species (H. cylindracea), 1 nematode species (C. ornata), and 1 acanthocephalan species (Acanthocephalus ranae). H. cylindracea and C. ornata were observed in both of the mountain frogs.

  19. Atividade da tripsina em rã-touro na fase pós-metamórfica Trypsin activity of the bullfrog in the post-metamorphic phase

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Tavares Braga

    2004-08-01

    Full Text Available Com o objetivo de avaliar a atividade enzimática da tripsina no conteúdo intestinal da rã-touro (Rana catesbeiana Shaw, 1802, 320 animais com peso médio de 3,6 g foram distribuídos em baias-teste com temperatura e fotoperíodo controlados. As rãs selecionadas na fase pós-metamórfica receberam ração comercial extrusada ad libitum. Durante 87 dias de experimento, foram efetuadas 29 coletas em intervalos de 1 a 8 dias. As coletas do conteúdo intestinal foram feitas mediante a insensibilização das rãs em gelo e água e posterior isolamento do intestino delgado. Após cada coleta, todo o material foi congelado em nitrogênio líquido e armazenado em freezer, para posterior liofilização. A determinação da atividade da tripsina foi realizada utilizando-se Benzoil-D, L-Arginina p-nitroanilida (D, L-BApNA como substrato. A atividade da tripsina foi registrada no primeiro dia de experimento; a fase inicial foi marcada pelo aumento da atividade da tripsina até a estabilidade, quando os animais ainda estavam na fase de imago. O período subseqüente (até o final do experimento foi caracterizado pela manutenção da estabilidade da atividade e pela atividade específica da tripsina. Pode-se concluir que a rã-touro apresenta capacidade para digestão de alimentos de origem protéica, recomendando-se, na fase inicial, uso de ração rica em proteína.With the objective of evaluating the enzymatic activity of the trypsin in the intestinal content of the bullfrog (Rana catesbeiana Shaw, 1802, 320 animals with average weight of 3.6 grams were distributed in stall-test with temperature and photoperiod controlled. The frogs selected in the post-metamorphic phase were fed commercial extruded diet ad libitum. For 87 days of experiment, 29 collections were performed at intervals varying from one to eight days. The collections of the intestinal content were performed by the desensitization of the frogs in ice and water and subsequent isolation of

  20. α-ENaC in bullfrog embryo: expression in cement gland, gills and skin.

    Science.gov (United States)

    Fujimaki-Aoba, Kayo; Tanaka, Kayoko; Inomata, Reiko; Jensik, Philip J; Takada, Makoto

    2014-01-01

    The epithelial sodium channel (ENaC) is involved in Na(+) responses such as Na(+) absorption and salt taste. The alpha ENaC subunit (α-ENaC) is expressed in the skin of both the adult and larval (tadpole) bullfrog. α-ENaC expression in the developing bullfrog embryo has not been previously investigated. In this study, the expression of α-ENaC at various stages (Sts.) of bullfrog embryonic development is assessed by western blot and immunofluorescence analysis. Bullfrog α-ENaC (α-fENaC) protein was detected by western blot in embryos at Sts. (Gosner/Shumway) 19, 21 and 25. Immunofluorescence studies indicate that α-fENaC was localized to the embryonic cement glands at St. 18 (muscular response), St. 19 (heart beat) and St. 21 (mouth open and/or cornea transparent), to the external gills at St. 21 and to the outermost cell-layer of the skin at St. 25 (operculum complete). The function(s) of ENaC in these embryonic structures remain to be elucidated.

  1. Reproductive interference between Rana dalmatina and Rana temporaria affects reproductive success in natural populations.

    Science.gov (United States)

    Hettyey, Attila; Vági, Balázs; Kovács, Tibor; Ujszegi, János; Katona, Patrik; Szederkényi, Márk; Pearman, Peter B; Griggio, Matteo; Hoi, Herbert

    2014-10-01

    Experimental evidence suggests that reproductive interference between heterospecifics can seriously affect individual fitness; support from field studies for such an effect has, however, remained scarce. We studied reproductive interference in 25 natural breeding ponds in an area where two ranid frogs, Rana dalmatina and Rana temporaria, co-occur. The breeding seasons of the two species usually overlap and males of both species are often found in amplexus with heterospecific females, even though matings between heterospecifics produce no viable offspring. We estimated species abundance ratios based on the number of clutches laid and evaluated fertilization success. In ponds with low spatial complexity and a species abundance ratio biased towards R. temporaria, the average fertilization success of R. dalmatina eggs decreased, while this relationship was not detectable in spatially more complex ponds. Fertilization success of R. temporaria did not decrease with increasing relative numbers of heterospecifics. This asymmetry in fitness effects of reproductive interference may be attributed to R. temporaria males being more competitive in scramble competition for females than R. dalmatina males. Our study is among the first to demonstrate that in natural breeding populations of vertebrates interference among heterospecifics has the potential to substantially lower reproductive success at the population level, which may in turn affect population dynamics.

  2. Agro-climatic Division of Rana chensinensis in Fushun

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Based on data collected by 3 basic weather stations in Fushun City and 47 automatic weather stations in the whole region,we selected indexes suitable for agro-climatic division of Rana chensinensis,and carried out a study on agro-climatic division of Rana chensinensis in this region.Annual active accumulated temperature ≥10 ℃ and precipitation during April and September are used as basic calculation factors,and we use climatic aridity to make climatic division of Rana chensinensis in Fushun City.According to relevant indexes,we divide Fushun City into 3 regions,namely most appropriate,appropriate and general regions.Finally,countermeasures and suggestions are put forward for providing reference for agricultural production.

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

    Science.gov (United States)

    Loman, Jon; Lardner, Björn

    2009-11-01

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

  4. Leukotriene C4 action and metabolism in the isolated perfused bullfrog heart.

    Science.gov (United States)

    Herman, R P; Heller, R S; Canavan, C M; Herman, C A

    1988-08-01

    The effects of leukotrienes (LTs) have been widely studied in the isolated perfused mammalian heart; however, little is known about the effect or metabolism of LTs in the isolated bullfrog heart. Isolated perfused bullfrog hearts were administered randomized doses of LTC4, LTD4, or LTE4. The cardiac parameters of heart rate, developed tension, and its first derivative (dT/dt) were recorded. LTC4 was the most potent of the leukotrienes tested in eliciting positive inotropic effects. LTD4 and LTE4 were equally effective but about one order of magnitude less potent than LTC4. None of the LTs showed any chronotropic effects in this preparation. A series of [3H]LTC4 metabolism experiments were carried out using whole perfused hearts and minced bullfrog heart tissue. Isolated perfused bullfrog hearts administered [3H]LTC4 converted significant amounts to [3H]LTD4, and to a lesser degree, [3H]LTE4, during the 6-min course of collection. Both minced atrial and ventricular tissue converted [3H]LTC4 to radioactive metabolites that co-migrated with authentic LTD4 and LTE4 standards. In both tissues, the major product was [3H]LTD4, with smaller amounts of [3H]LTE4 produced. The atrium converted significantly more [3H]LTC4 to its metabolites than did the ventricle. The metabolism of [3H]LTC4 to [3H]LTD4 by both tissues was virtually abolished in the presence of serine borate. Cysteine had no effect on [3H]LTE4 production. The data in this study demonstrate that leukotrienes have the opposite inotropic effect on the heart when compared with mammals. Also in contrast to mammals, frogs metabolize LTC4 to a less potent compound and may use the LTC4 to LTD4 conversion as a mechanism of LTC4 inactivation.

  5. Cinco ranas y un sátiro

    OpenAIRE

    2010-01-01

    1 dibujo sobre papel; 145 x 114. Tinta. Papel. - Esbozo de conco ranas y un sátiro. - En el reverso de un sobre enviado a Miguel de Unamuno desde Bermeo (Vizcaya) el 1 de septiembre de 1899. - Buena conservación.

  6. Morphometric growth characteristics and body composition of bullfrog tadpoles in captivity

    Directory of Open Access Journals (Sweden)

    Cleber Menegasso Mansano

    2014-10-01

    Full Text Available Feed management needs to be improved in frog farming to reduce the indirect effects of inadequate feeding and, consequently, to increase growth rates and nutrient deposition, obtaining better quality animals. The objective of this study was to establish morphometric growth curves for bullfrog tadpoles (Lithobates catesbeianus and to determine nutrient deposition in the carcass. A total of 6,480 bullfrogs (Gosner stage 25 received an experimental diet (26.23% digestible protein and 32.68% crude protein and a commercial diet (37.92% crude protein ad libitum. A Gompertz model was used to describe the growth curve. Tadpoles fed the experimental diet presented higher final protein deposition. In addition, the sigmoidal curve was much more homogenous, indicating a more constant daily protein deposition rate. The Gompertz model provided an excellent fit of the data to describe the morphometric growth curve and carcass nutrient deposition of bullfrog tadpoles, showing that animals fed the experimental diet presented a better growth rate and nutrient deposition.

  7. 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.

  8. Mitotic activity in dorsal epidermis of Rana pipiens.

    Science.gov (United States)

    Garcia-Arce, H.; Mizell, S.

    1972-01-01

    Study of statistically significant rhythms of mitotic division in dorsal epidermis of frogs, Rana pipiens, exposed to a 12:12 light:dark environment for 14 days. The results include the findings that (1) male animals have a primary period of 22 hr in summer and 18 hr in winter, (2) female animals have an 18 hr period, and (3) parapinealectomy and blinding abolish the rhythm.

  9. Behavioural consistency and life history of Rana dalmatina tadpoles

    OpenAIRE

    Urszán, Tamás Janós; Török, János; Hettyey, Attila; Garamszegi, László Z; Herczeg, Gábor

    2015-01-01

    The focus of evolutionary behavioural ecologists has recently turned towards understanding the causes and consequences of behavioural consistency, manifesting either as animal personality (consistency in a single behaviour) or behavioural syndrome (consistency across more behaviours). Behavioural type (mean individual behaviour) has been linked to life-history strategies, leading to the emergence of the integrated pace-of-life syndrome (POLS) theory. Using Rana dalmatina tadpoles as models, w...

  10. Cloning and expression of vacuolar proton-pumping ATPase subunits in the follicular epithelium of the bullfrog endolymphatic sac

    OpenAIRE

    Yajima, Shinya; Kubota, Makoto; Nakakura, Takashi; Hasegawa, Takahiro; Katagiri, Nobuto; Tomura, Hideaki; Sasayama, Yuichi; Suzuki, Masakazu; Tanaka, Shigeyasu

    2007-01-01

    In an investigation aimed at clarifying the mechanism of crystal dissolution of the calcium carbonate lattice in otoconia (the mineral particles embedded in the otolithic membrane) of the endolymphatic sac (ELS) of the bullfrog, cDNAs encoding the A- and E-subunits of bullfrog vacuolar proton-pumping ATPase (V-ATPase) were cloned and sequenced. The cDNA of the A-subunit consisted of an 11-bp 5′-untranslated region (UTR), a 1,854-bp open reading frame (ORF) encoding a protein comprising 617 am...

  11. 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.

  12. A study in motion sickness - Saccular hair cells in the adult bullfrog

    Science.gov (United States)

    Cohen, G. M.; Reschke, M.; Homick, J.

    1982-01-01

    The bullfrog's saccule were examined using light and scanning electron microscopy. No evidence of a striola was found. Type A hair cells were not only distributed peripherally, but also throughout the central macula, though far less frequently than the dominant type D. Two primary hair cell types were distinguished, which corresponded to the ciliary patterns: type A cilia are associated with short, conical hair cells, and type D cilia are associated with long, cylindrical hair cells. Each displays at least one subtype, which may represent developmental precursors. The otolithic membrane is crisscrossed with tunnels and topped with statoconia.

  13. When local anesthesia becomes universal: pronounced systemic effects of subcutaneous lidocaine in bullfrogs (Lithobates catesbeianus)

    DEFF Research Database (Denmark)

    Williams, catherine; Alstrup, Aage Kristian Olsen; Bertelsen, Mads

    2017-01-01

    Sodium channel blockers are commonly injected local anesthesia but are also routinely used in general immersion anesthesia for fish and amphibians. Here we report the effects of subcutaneous injection of lidocaine (5 or 50 mg kg-1) in the hind limb of bullfrogs (Lithobates catesbeianus) on reflexes......). Reflexes were regained over 4 h. Systemic sedative effects were not coupled to local anti-nociception, as a forceps pinch test at the site of injection provoked movement at the height of the systemic effect (tested at 81 ± 4 min). Amphibians are routinely subject to general anesthesia via exposure...

  14. A microsatellite-based method for genotyping diploid and triploid water frogs of the Rana esculenta hybrid complex

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager

    2005-01-01

    Rana esculenta is a hybrid between Rana lessonae (LL) and Rana ridibunda (RR), and hybrids may be diploid (LR) or triploid (LLR or LRR). Genotypes can be roughly determined from erythrocyte size and morphometry in adult frogs, but accurate genotyping requires more labourious methods. Here I...

  15. On the presence of Rana ridibunda ridibunda Pallas in the Netherlands

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1975-01-01

    Since long there has been a dispute whether in the Netherlands there occur one or two species of green frogs of the genus Rana. There has never been any doubt concerning the presence of Rana esculenta Linnaeus, a species widely distributed throughout the country (Van de Bund, 1964, 1968). The first

  16. 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

    Introduction The Oregon spotted frog (Rana pretiosa) is a highly aquatic frog that has been extirpated from a large portion of its historic range in the Pacific Northwest, and remaining populations are reduced and isolated (Hayes 1997, Pearl and Hayes 2005). Loss and alteration of marsh habitat, predation and competition from exotic fish and bullfrogs, and degraded water quality from agriculture and livestock grazing are implicated in their decline (Hayes 1997, Pearl and Hayes 2005). In 2001, an interagency team translocated a population of frogs from a site that was to be eliminated by the renovation of the dam impounding Wickiup Reservoir, to newly created ponds at Dilman Meadow (121i?? 39' 52" W, 43i?? 41' 58" N), 2.5 km from the original site in central Oregon, USA. We monitored Oregon spotted frog demography and movements at Dilman Meadow for > 4 yr to assess the efficacy of these mitigation efforts, determine metrics for long-term monitoring, and inform future management at the site. More broadly, many aspects of Oregon spotted frog life history are poorly known, so understanding demography and movement patterns is likely to be useful in its conservation. Although wildlife translocations have been attempted extensively as conservation means, few such projects have been sufficiently monitored for demographic rates to understand the causes for the translocation's success or failure (Dodd and Seigel 1991). Our objective here is to document demographic and movement patterns in the population of Oregon spotted frog at Dilman Meadow so that this information will be available to guide management decisions. To better evaluate amphibian population responses to management actions it is important to consider the contribution of each life history stage and both genders to the balance of reproduction and mortality. Population growth or contraction occurs as a complicated function of the probability of breeding, fecundity, and survival during multiple life history stages

  17. Fecal collection methods for the determination of protein digestibility in bullfrogs

    Directory of Open Access Journals (Sweden)

    Marta Verardino De Stéfani

    2015-08-01

    Full Text Available Adequate methods for the determination of protein digestibility in bullfrogs are important for the understanding of nutrient utilization. Therefore, this study evaluated two methods of feces collection: intestinal dissection and fecal decantation, using cylindric-conical tanks. Frogs were fed with a commercial diet (45% crude protein which was ground and supplemented with 0.5% chromium oxide III. The frogs were fasted 48h before force-feeding (5% of the animal's live weight. For the decantation method, the animals were sacrificed 36 h after force-feeding and feces were collected directly from the large intestine. For the sedimentation method, feces were collected when they appeared in the tubes attached to the front end of the cylindric tanks. No significant difference (P>0.05 in the apparent digestibility coefficients of crude protein for dietary was observed between the methods tested (74.0% and 76.4% for the dissection and decantation methods, respectively. In conclusion, both methods can be used for the determination of protein digestibility of bullfrog feeds

  18. Efferent control of the electrical and mechanical properties of hair cells in the bullfrog's sacculus.

    Directory of Open Access Journals (Sweden)

    Manuel Castellano-Muñoz

    Full Text Available BACKGROUND: Hair cells in the auditory, vestibular, and lateral-line systems respond to mechanical stimulation and transmit information to afferent nerve fibers. The sensitivity of mechanoelectrical transduction is modulated by the efferent pathway, whose activity usually reduces the responsiveness of hair cells. The basis of this effect remains unknown. METHODOLOGY AND PRINCIPAL FINDINGS: We employed immunocytological, electrophysiological, and micromechanical approaches to characterize the anatomy of efferent innervation and the effect of efferent activity on the electrical and mechanical properties of hair cells in the bullfrog's sacculus. We found that efferent fibers form extensive synaptic terminals on all macular and extramacular hair cells. Macular hair cells expressing the Ca(2+-buffering protein calretinin contain half as many synaptic ribbons and are innervated by twice as many efferent terminals as calretinin-negative hair cells. Efferent activity elicits inhibitory postsynaptic potentials in hair cells and thus inhibits their electrical resonance. In hair cells that exhibit spiking activity, efferent stimulation suppresses the generation of action potentials. Finally, efferent activity triggers a displacement of the hair bundle's resting position. CONCLUSIONS AND SIGNIFICANCE: The hair cells of the bullfrog's sacculus receive a rich efferent innervation with the heaviest projection to calretinin-containing cells. Stimulation of efferent axons desensitizes the hair cells and suppresses their spiking activity. Although efferent activation influences mechanoelectrical transduction, the mechanical effects on hair bundles are inconsistent.

  19. Model study of combined electrical and near-infrared neural stimulation on the bullfrog sciatic nerve.

    Science.gov (United States)

    You, Mengxian; Mou, Zongxia

    2017-07-01

    This paper implemented a model study of combined electrical and near-infrared (808 nm) neural stimulation (NINS) on the bullfrog sciatic nerve. The model includes a COMSOL model to calculate the electric-field distribution of the surrounding area of the nerve, a Monte Carlo model to simulate light transport and absorption in the bullfrog sciatic nerve during NINS, and a NEURON model to simulate the neural electrophysiology changes under electrical stimulus and laser irradiation. The optical thermal effect is considered the main mechanism during NINS. Therefore, thermal change during laser irradiation was calculated by the Monte Carlo method, and the temperature distribution was then transferred to the NEURON model to stimulate the sciatic nerve. The effects on thermal response by adjusting the laser spot size, energy of the beam, and the absorption coefficient of the nerve are analyzed. The effect of the ambient temperature on the electrical stimulation or laser stimulation and the interaction between laser irradiation and electrical stimulation are also studied. The results indicate that the needed stimulus threshold for neural activation or inhibition is reduced by laser irradiation. Additionally, the needed laser energy for blocking the action potential is reduced by electrical stimulus. Both electrical and laser stimulation are affected by the ambient temperature. These results provide references for subsequent animal experiments and could be of great help to future basic and applied studies of infrared neural stimulation (INS).

  20. Studi Mikroanatomi Pankreas Kodok Lembu Menggunakan Metode Pewarnaan Baku dan Immunohistokimia (MICROSCOPICAL STUDY OF PANCREAS OF BULLFROG USING CONVENTIONAL AND IMMUNOSTAINING METHODS

    Directory of Open Access Journals (Sweden)

    I Ketut Mudite Adnyane

    2012-03-01

    Full Text Available Morphology, distribution and relative frequency of endocrine cells in the pancreas Bullfrog (Ranacatesbeiana were studied using conventional and immunohistochemical methods. Samples pancreas takenfrom ten adult Bullfrogs (five males and five females. In general, pancreas of the Bullfrog consists ofexocrine portion, endocrine portion (Langerhans islets and ducts. The Langerhans islets were distributedamong the exocrine portion of pancreas. Endocrine cells in the pancreas of Bullfrog were polimorph, round,oval or triangular in shapes with bipolar cytoplasmic granules. Glucagon cells were distributed mainly inthe peripheral, insulin cells in the center while the somatostatin cells in the area between glucagon andinsulin cells of Langerhans islet. The number of the glucagon cells were higher compare to the number ofinsulin and somatostatin cells.

  1. Efectivos poblacionales de la Rana ágil (Rana dalmatina y uso del hábitat reproductor en Navarra

    Directory of Open Access Journals (Sweden)

    GOSA, Alberto

    2002-01-01

    Full Text Available La población navarra de Rana dalmatina se encuentra fragmentada en 4 núcleos incomunicados, con baja disponibilidad de humedales para la reproducción (entre 2 y 15 por área. La población de hembras adultas fluctúa anualmente entre 1000 y 1500 individuos, sin considerar de la La Barranca, todavía no investigada. La conservación de la especie depende de la gestión de las zonas húmedas.

  2. Population activity changes during a trial-to-trial adaptation of bullfrog retinal ganglion cells.

    Science.gov (United States)

    Ding, Wei; Xiao, Lei; Jing, Wei; Zhang, Pu-Ming; Liang, Pei-Ji

    2014-07-09

    A 'trial-to-trial adaptation' of bullfrog retinal ganglion cells in response to a repetitive light stimulus was investigated in the present study. Using the multielectrode recording technique, we studied the trial-to-trial adaptive properties of ganglion cells and explored the activity of population neurons during this adaptation process. It was found that the ganglion cells adapted with different degrees: their firing rates were decreased in different extents from early-adaptation to late-adaptation stage, and this was accompanied by a decrease in cross-correlation strength. In addition, adaptation behavior was different for ON-response and OFF-response, which implied that the mechanism of the trial-to-trial adaptation might involve bipolar cells and/or their synapses with other neurons and the stronger adaptation in the ganglion cells' OFF-responses might reflect the requirement to avoid possible saturation in the OFF circuit.

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

    Science.gov (United States)

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

    2008-01-01

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

  4. Range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) in northwestern North America

    Science.gov (United States)

    Funk, W.C.; Pearl, C.A.; Draheim, H.M.; Adams, M.J.; Mullins, T.D.; Haig, S.M.

    2008-01-01

    The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis revealed one main R. pretiosa clade and three main R. luteiventris clades, two of which overlapped in southeastern Oregon. The three R. luteiventris clades were separated from each other by high levels of sequence divergence (average of 4.75-4.97%). Two divergent clades were also uncovered within the Great Basin. Low genetic variation in R. pretiosa and the southeastern Oregon clade of R. luteiventris suggests concern about their vulnerability to extinction. ?? 2008 Elsevier Inc.

  5. New Replacement Name for Rana paradoxa Mocquard, 1890 with Designations of Lectotypes for Rana paradoxa and Rana conspicil-lata Günther, 1872:Both Synonymized with Limnonectes kuhlii (Tschudi, 1838) (Dicroglossidae:Dicroglossinae)

    Institute of Scientific and Technical Information of China (English)

    Masafumi MATSUI; Alain DUBOIS; Annemarie OHLER

    2013-01-01

    Fanged frogs, now called Limnonectes kuhlii, from Borneo are remotely related to true Javanese L. kuhlii. For future taxonomy of Bornean fanged frogs, we ifx the nomenclatural status of two existing names, Rana conspicillata Günther, 1872 and Rana paradoxa Mocquard, 1890. Morphological comparison of the type-series revealed heterospeciifc relationships of the two species. For R. conspicillata, we designate BMNH 1947.2.29.20 as the lectotype, and for R. para-doxa, we also designate MNHN 1889.222 as the lectotype and propose a replacement name Limnonectes mocquardi, in order to stabilize their nomenclature.

  6. Western spotted frog (Rana pretiosa) distribution in the Bonneville Basin of western Utah: Research in progress

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides information on the western spotted frog (Rana pretiosa) which occurs in Tule Valley, Utah. The following topics are discussed; general...

  7. The Developmental Effects Of A Municipal Wastewater Effluent On The Northern Leopard Frog, Rana pipiens

    Science.gov (United States)

    Wastewater effluents are complex mixtures containing a variety of anthropogenic compounds, many of which are known endocrine disruptors. In order to characterize the development and behavorial effects of such a complex mixture, northern leopard frogs, Rana pipiens, were e...

  8. Growth in weight and of some tissues in the bullfrog: fitting nonlinear models during the fattening phase

    Directory of Open Access Journals (Sweden)

    Marcelo Maia Pereira

    2014-12-01

    Full Text Available Knowledge of the growth of animals is important so that zootechnical activity can be more accurate and sustainable. The objective of this study was to describe the live weight, development of liver tissue and fat body, leg growth, and cumulative food intake of bullfrogs during the fattening phase using nonlinear models. A total of 2,375 bullfrog froglets with an initial weight of 7.03 ± 0.16 g were housed in five fattening pens (12 m². Ten samplings were performed at intervals of 14 days to obtain the variables studied. These data were used to estimate the parameters of Gompertz and logistic models as a function of time. The estimated values of weight (Wm and food intake (FIm at maturity and time when the growth rate is maximum (t* were closer to expected values when the logistic model was used. The Wm values for live weight and liver, adipose and leg weights and the FIm value for food intake were 343.7, 15.7, 19.6, 96.03 and 369.3 g, respectively, with t* at 109, 98, 105, 109 and 107 days. Therefore, the logistic model was the best model to estimate the growth and food intake of bullfrogs during the fattening phase.

  9. Population size, survival, growth, and movements of Rana sierrae

    Science.gov (United States)

    Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

    2013-01-01

    Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

  10. Extraction and antioxidant activity of polysaccharides from Rana chensinensis skin.

    Science.gov (United States)

    Wang, Zhanyong; Zhao, Yuanyuan; Su, Tingting

    2015-01-22

    The extraction process of polysaccharides from Rana chensinensis skin was optimized by using a Box-Behnken design. The optimum extraction conditions were as follows: extraction time, 4.96h; extraction temperature, 100°C; ratio of water to raw material, 60; and extraction frequency, 1. Under these conditions, the experimental polysaccharide yield was 2.03±0.14%, which agreed with the predicted yield. The purified polysaccharide RCSP II was successfully obtained by diethylaminoethanol-Sepharose and Sepharose CL-6B column chromatography. In vitro experiments showed that RCSP II exhibited a strong scavenging activity against superoxide anion and 1,1-diphenyl-2-picrylhydrazyl radicals but a weak scavenging activity against hydroxyl radicals. RCSP II also showed a strong reducing capacity. Thus, this polysaccharide can be used as a natural antioxidant in functional foods or medicines.

  11. Nephrotoxic effects of lead nitrate in Rana ridibunda

    Energy Technology Data Exchange (ETDEWEB)

    Loumbourdis, N.S. [Department of Zoology, University of Thessaloniki, 54124, Thessaloniki (Greece)

    2003-09-01

    The impact of lead (Pb) on kidney histopathology of the frog Rana ridibunda was investigated. Female frogs were exposed for 4, 10 and 30 days to 14 ppm lead (as lead nitrate). All the lead concentrations and many histological changes were time dependent. Light microscopy of kidney revealed morphological changes mainly in the proximal convoluted tubule (PCT) cells. The most severe changes such as vacuolation, Perl's stained material, infiltration, brush border destruction and proximal tubule damage were detected in the animals exposed for 10 and 30 days. Karyomegaly was highest at 10-days exposure, probably as a result of intense stress caused by the lead. Some PCT in the 30-days-exposed animals were von Kossa's method positive, suggesting the presence of calcium. The possibility is discussed that some of these changes, such as karyomegaly and intranuclear inclusions, might be preneoplastic if lead was supplied at high concentrations and for long time. (orig.)

  12. Widespread bacterial infection affecting Rana temporaria tadpoles in mountain areas

    Directory of Open Access Journals (Sweden)

    Rocco Tiberti

    2011-06-01

    Full Text Available Periodic mass die-offs of Rana temporaria tadpole populations have occurred in the ponds of prealpine mountain areas of Brescia (northern Italy since the early 2000s. The author reports some observational data and analytical results from three sites: tadpoles from mortality events had erythema, especially on the legs, suggestive of septicemia. Bacterial culture of these tadpoles revealed Aeromonas hydrophila and Aeromonas sobria, two organisms often associated with Red leg disease. Egg mass counts from 29 pastureland ponds did not revealed breeding activity declines over five years in the Monte Guglielmo area. Aeromonas hydrophila and Aeromonas sobria usually behave as opportunistic bacteria that can become pathogenic after suppression of the immune system by endogenous or exogenous stressors. Thus, a plurality of environmental factors may contribute to mortality events; some of them are discussed, including loss of high altitude breeding ponds resulting in overcrowding and poor water quality in remaining ponds and the presence of other pathogens.

  13. Alimentación de las ranas pardas, Rana gr. temporaria, en el circo de Piedrafita, (Pirineos, España

    Directory of Open Access Journals (Sweden)

    Rodríguez Vieites, D.

    1997-12-01

    Full Text Available Feeding of high Pyrenean mountain brown frogs were studied in the pre-wintering period. The main prey is beetles (44'97o, two-winged flies (12'9% and bees, wasps, ants, etc (11'4%. For the whole of the frogs, the most frequent prey size is the small (smaller than 10 mm. Big frogs tend to consume bigger prey in not ,o. many quantity, while small frogs consume more quantity of preys but smaller in size. From prey way of life, frogs eat mainly terrestrial and aerial preys, although capture of aquatic prey was observed (11'5% and these preys were eaten inside the water.

    Se ha estudiado la dieta de las ranas pardas en alta montaña pirenaica durante el periodo pre-invernal. Las ranas consumen principalmente coleópteros (44'9%, dípteros (12'9% e himenópteros (11'4%. Para el conjunto de todas las ranas estudiadas, las presas más consumidas son las de pequeño tamaño (menores de 10 mm. Las ranas de mayor talla tienden a consumir presas más grandes y en poca cantidad, mientras que las ranas pequeñas consumen más presas aunque de pequeño tamaño. En cuanto a forma de vida las presas más consumidas son terrestres y aéreas, aunque también se ha comprobado la captura de presas acuáticas (11'5% que son consumidas por las ranas dentro del agua.

  14. Dye-coupling among frog (Rana catesbeiana) taste disk cells.

    Science.gov (United States)

    Sata, O; Okada, Y; Miyamoto, T; Sato, T

    1992-09-01

    1. Dye-coupling among taste disk cells in the bullfrog fungiform papillae was examined histologically by injecting a fluorescent dye (Lucifer yellow) into the cell, and the effects of the dye-coupling on depolarizing responses induced by taste stimuli were studied electrophysiologically. 2. With dye injection into a taste cell, dye-coupling was found between taste cells (23%) or between taste cell and supporting cell (28%). With dye injection into a supporting cell, dye-coupling was found between supporting cells (34%) or between supporting cell and taste cell (27%). 3. Depolarizing responses recorded from either a taste cell or a supporting cell to stimulation with 0.5 M NaCl or 10 mM quinine-HCl were the same in amplitude whether the dye-coupling to another cell was present or not. On the other hand, depolarizing responses recorded from a taste cell for 0.5 mM acetic acid became significantly larger when dye-coupled to a supporting cell. 4. It is concluded that gustatory transduction for acid stimuli is influenced by supporting cells coupled to taste cells.

  15. LOS FANTASMAS EN RANAS DE ARISTÓFANES

    Directory of Open Access Journals (Sweden)

    Soraya Planchas Gallarte

    2015-05-01

    Full Text Available THE GHOSTS IN ARISTOPHANES’ FROGS. The aim of the following paper is to present and analyze the passages of the comedies of Aristophanes related to ghostly apparitions. By offering an overview of this issue, so recurrent among classical authors, we will be able to sketch, on the one hand, how the Athenian comic playwright configures this topic in one of his works. On the other, by contextualizing Aristophanes’ treatment of ghosts in his genre, we will have the opportunity of focusing on the similarities, and possible innovations introduced by the poet among ancient Greek authors. Keywords: Aristophanes, ghost, Frogs, apparition, comedy. // LOS FANTASMAS EN RANAS DE ARISTÓFANES. Resumen: La finalidad de nuestra investigación consiste principalmente en presentar y analizar aquellos pasajes de las comedias aristofánicas relacionados con el tópico de las apariciones fantasmales. Comenzaremos ofreciendo una visión general de este motivo, tan recurrente entre los autores clásicos, para, a continuación, detenernos exclusivamente en el tratamiento que hizo el comediógrafo ateniense. Creemos que una detenida observación de las similitudes e innovaciones de estas cuestiones nos llevará, en primer lugar, a delimitar una visión concreta del tópico dentro del género cómico y, en segundo lugar, a insertar una pieza clave en el puzle de la concepción de los fantasmas a lo largo de la literatura grecolatina. Palabras clave: Aristófanes, Ranas, fantasmas, apariciones, comedia.

  16. 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.

  17. Pharmacological and physiological properties of the after-hyperpolarization current of bullfrog ganglion neurones.

    Science.gov (United States)

    Goh, J W; Pennefather, P S

    1987-12-01

    1. The slowly decaying, calcium-dependent after-hyperpolarization (a.h.p.) that follows action potentials in bullfrog ganglion B cells has previously been shown to be generated by a potassium current called IAHP. We have recorded IAHP using a switched, single-electrode hybrid clamp where current-clamp mode was changed to voltage-clamp mode immediately after repolarization of a spike or the last spike of a train. 2. Reduction of extracellular calcium reduced the decay time of IAHP following a single spike. At all levels of extracellular calcium tested (0.5-4 mM), the decay time of IAHP was longer following a train of action potentials than following a single action potential. Thus, the time course of IAHP evoked by action potentials is a function of the calcium load induced by the action potentials. Conversely, agents that reduce the amount of IAHP activated without affecting its rate of decay, probably do not affect calcium influx. 3. Muscarine (2 or 10 microM) inhibits IAHP following an action potential by at most 30% and has no effect on decay rate of IAHP. These results suggest that muscarine has little or no effect on either calcium influx or sequestration. Decay of the a.h.p. is accelerated by muscarine but this effect is due to an increased leak conductance. 4. Charybdotoxin (CTX) between 4 and 20 nM, prolongs action potential duration in a manner consistent with blockade of the voltage- and calcium-dependent potassium current (Ic) involved in spike repolarization in these cells. This action is consistent with its reported action on analogous channels in other systems. However, CTX also reduces IAHP. Thus, in bullfrog ganglion neurones, two distinct calcium-dependent potassium currents exhibit a comparable sensitivity to CTX. This cannot be due to a decreased influx of calcium because the decay rate of IAHP following an action potential is unchanged. The action of CTX was observed with both crude and purified preparations of CTX. 5. Apamin (25 nM) and

  18. Microscopic morphology and testis morphometry of captivity-bred Adult bullfrogs (Lithobates catesbeianus Shaw, 1802

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    Jaqueline Carlos

    2009-12-01

    Full Text Available The aim of this work was to study the testicular morphometry of captivity-bred adult bullfrogs. Fifteen young adult male were studied, in the rainy season and a lengthy photoperiod. The GSI was established at 0.15%. The nuclear diameter of germinative and Leydig cells, the nucleolus diameter of Sertoli cells and the area of cysts and tubules were determined and the mean number of ISPC, IISPC and SPT per cyst and the mean number of cysts per tubule was estimated. The nucleoplasmatic proportion of the nucleus of the Leydig cell was 76.22%, indicating less cytoplasmic activity. Eight generations of spermatogonia were found. The spermatogenesis efficiency in meiosis and in mitosis was 63 and 49%, respectively. The spermatogenesis of bullfrog fited in the pattern of other captivity Anurans, with differences as the morphology of Sertoli and Leydig cells nuclei.A morfometria é uma importante ferramenta para a biologia estrutural, permitindo estudos estereológicos e análises quantitativas. Existem muitos pontos a serem esclarecidos sobre a morfometria testicular desta espécie, que objetivamos desvendar neste trabalho. Quinze machos adultos foram estudados, em período chuvoso e de fotoperíodo longo (dezembro, 2000. O IGS encontrado foi de 0.15%. O diâmetro nuclear das células germinativas e da célula de Leydig, o diâmetro nucleolar das células de Sertoli e a área dos cistos e túbulos foram determinados. O número médio de ISPC, IISPC e SPT por cisto e o número médio de cisto por túbulo foi estimado. A proporção nucleoplasmática do núcleo da célula de Leydig foi de 76.22%, indicando pouca atividade citoplasmática. Oito gerações de espermatogônia foram estimadas. A eficiência da espermatogênese na meiose e mitose foi de 63% e49%, respectivamente. A espermatogênese de rãtouro segue os padrões dos demais Anuros de cativeiro, apresentando diferenças nos núcleos das c��lulas de Sertoli e Leydig.

  19. Toxicity of atrazine, glyphosate, and quinclorac in bullfrog tadpoles exposed to concentrations below legal limits.

    Science.gov (United States)

    Dornelles, M F; Oliveira, G T

    2016-01-01

    This work sought to ascertain survival and possible changes in levels of glycogen, triglycerides, total lipids, cholesterol, protein, and lipid peroxidation in gills, liver, and muscle of bullfrog tadpoles (Lithobates catesbeianus) exposed to low concentrations of atrazine (2.5 μg L(-1)), glyphosate (18 μg L(-1)), and quinclorac (0.025 μg L(-1)) at laboratorial conditions. Tadpoles showed a reduction of glycogen and triglyceride in all organs and an increase in lipid peroxidation (LPO) compared with control animals. Total lipid in gills and muscle increased in exposure to atrazine, and gills alone in exposure to glyphosate, but decreased in gills, liver, and muscle after quinclorac. Cholesterol increased in gills and liver after atrazine, in gills and muscle after glyphosate, and decreased in liver after quinclorac. Total protein in gills decreased after exposure to all herbicides, increased in muscle after atrazine, and in liver and muscle after quinclorac. These findings show that at concentrations of these herbicides tested can lead to an increase in energy expenditure to maintain homeostasis and survival of these animals despite the increase in lipid peroxidation levels in all organs analyzed. Responses observed can be one of the factors responsible for the decline in the number of amphibians around the world.

  20. The action and metabolism of peptide leukotrienes in the isolated bullfrog lung.

    Science.gov (United States)

    Heller, R S; Herman, R P; Herman, C A

    1989-04-01

    Leukotrienes (LTs) have been shown to cause contraction of mammalian airway smooth muscle. In this study, LTC4, LTD4, and LTE4 were tested on isolated strips of bullfrog lung. LTC4, LTD4, and LTE4 (10(-7) to 3 x 10(-10) M) stimulated lung contraction. LTC4 was the most potent, with LTD4 and LTE4 being of equal but lower potency. The cyclooxygenase inhibitors, indomethacin and ibuprofen, had no effect on the strength of leukotriene-induced contraction. In addition, the effects of three mammalian LTD4 receptor antagonists, L-649,923, L-648,051, and LY171883 were tested. All three antagonists failed to block LTC4-simulated contraction, but were effective blockers of LTD4. LTE4-stimulated contractions were significantly blunted by all three antagonists, but the extent of blockade was less than for LTD4. Significant bioconversion of [3H]LTC4 to LTD4 and LTE4 occurred in minced lung preparations but not in lung strips. Peptide leukotrienes caused contraction in amphibian lung, though the order of potency differs from mammals. Like mammals, frogs appear to have two classes of leukotriene receptors, one for LTC4 and one for LTD4-LTE4. These results support the hypothesis that leukotriene receptors have been highly conserved through evolution, despite the fact that the nature of tissue responsiveness to leukotrienes has changed over evolutionary time.

  1. Time interval from ovulation to extrusion in female bullfrog in different photoperiods

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    Claudio Angelo Agostinho

    2011-08-01

    Full Text Available It was analyzed in this work the influence of photoperiod on time interval from ovulation induction period to extrusion of ovocits in female bullfrogs (Lithobates catesbeianus. It was used 54 females reared from metamorphosis to 9 months of age under three photoperiods: dark time (DL 0:24, 16 hours of daylight (DL 16:8 and 12 hours of daylight (DL 12:12. Ovulation was induced by intramuscular application of two doses of LHRHa with 12 hours of interval between the injections. After 10, 25, 28, 31, 34 and 37 hours from the first hormone injection, 10-gram samples (3,000 eggs were extracted from each female at each time interval and fertilized. Egg hatching rate was checked in each sample 72 hours after fertilization. Analysis of variance showed a significant effect of extrusion delay and the interaction between photoperiod and this delay. Extrusion should be carried out 33, 24 and 26 hours after the first hormone dosage in females reared in environments without light, with 12 hours of daylight and with 16 hours of daylight, respectively, to obtain the maximum fertilization rate.

  2. THE MOCHE BOTANICAL FROG (La rana botánica mochica

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    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.

  3. Ontogeny and localization of gamma-crystallins in Rana temporaria, Ambystoma mexicanum and Pleurodeles waltlii normal lens development

    NARCIS (Netherlands)

    Brahma, S.K.; McDevitt, David S.

    1974-01-01

    Rana pipiens lens γ-crystallin antibodies were used in the indirect immunofluorescence staining method to investigate the role of γ-crystallins in the normal lens development of the amphibians Rana temporaria, Ambystoma mexicanum and Pleurodeles waltlii Michah. In each case, the fluorescence was fir

  4. Ontogeny and localization of gamma-crystallins in Rana temporaria, Ambystoma mexicanum and Pleurodeles waltlii normal lens development

    NARCIS (Netherlands)

    Brahma, S.K.; McDevitt, David S.

    1974-01-01

    Rana pipiens lens γ-crystallin antibodies were used in the indirect immunofluorescence staining method to investigate the role of γ-crystallins in the normal lens development of the amphibians Rana temporaria, Ambystoma mexicanum and Pleurodeles waltlii Michah. In each case, the fluorescence was

  5. Age and body size of Rana amurensis from northeastern China

    Institute of Scientific and Technical Information of China (English)

    Wei CHEN; Xin LU

    2011-01-01

    Age and body size are two important demographic traits that determine the life history strategies of populations and species.We measured these two parameters of Rana amurensis,at a 900 m and a 500 m altitude site in northeastern China.At the two sites,age at first reproduction was 2 years for males and 3 years for females.The maximum age of males and females at the high-altitude site was 6 and 7 years,and 5 and 7 years at the low-altitude population,respectively.Females were significantly larger than males in both populations,due to greater age in both the high- and low-altitude sites.Body size of either males or females did not differ significantly between populations; only males showed increased body size at the high-altitude site when age effect was statistically controlled for.The increased cline of male body size may be attributable to delayed maturation of the sex due to a shorter growing season at high altitudes [Current Zoology 57 (6):781-784,2011].

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

    Science.gov (United States)

    Li, Xinyi; Liu, Jia; Zhang, Yuhui

    2016-06-01

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

  7. Structural study of the frog Rana temporaria larval stomach.

    Science.gov (United States)

    Rovira, J; Villaro, A C; Bodegas, M E; Valverde, E; Sesma, P

    1993-10-01

    The gastric wall of Rana temporaria tadpoles consists of a well-developed mucosa and thin muscular and serosa layers. Three cellular types--mucous, ciliated and endocrine cells--make up the lining epithelium. Different types of endocrine cells exist. Argyrophylic endocrine cells can be recognized in semithin sections of plastic-embedded material while non-argyrophylic endocrine cells can only be identified under the electron microscope. Glands are composed mainly of well-differentiated oxyntic cells and, occasionally, scarce endocrine cells. Oxyntic cells show abundant mitochondria and smooth endoplasmic reticulum, but do not contain zymogen granules as do those present in adults. Secretory canaliculi with microvilli are also well-developed. The lamina propria contains numerous vascular sinuses and nerve bundles which innervate the endothelium and some endocrine cells. The neuroendocrine regulation of frog gastric functions seems therefore to have developed in young tadpoles. Nerve fibers also innervate the muscular propria, which is composed of a single layer of smooth muscle cells. Underlying the muscle, connective fibers and a flattened layer of mesothelial cells make up the serosa. In summary, the structure of the frog larval stomach shows a well-differentiated histological pattern, especially referring to surface epithelium and glands. Some of the histological traits will also be present in adult frogs while others are characteristic of the tadpole's stage.

  8. Ultrastructure of venom glands in the frog (Rana esculenta).

    Science.gov (United States)

    De Perez, G; Hindelang, C

    1985-01-01

    Electron microscopic study of skin venom glands in the frog, Rana esculenta, revealed the syncytial structure of the inner (secretory) wall which presents two distinct zones: a basal (juxtamuscular) one, which contains nuclei and major cytoplasmic organelles, and an apical one where large electron-dense granules form and accumulate. Granules are seen to arise inside clusters of tightly packed smooth endoplasmic reticulum (SER) elements, which suggests that the SER system is mainly involved in synthesis of this material. A high glutaraldehyde concentration (5%) also reveals a poorly defined material filling the intergranular cytoplasm. No apical limits to the syncytium could be traced, which suggests massive holocrine secretion. Nerves insinuate between the muscle cells and occur all along the internal face of the muscular layer, sometimes in close contact with the syncytium. The gland duct, the wall of which consists of epidermal cells, is blocked, in contact with the gland, by an epidermal bud linked externally to the muscle layer surrounding the gland. Thus, only strong muscle tension such as to expel all or part of the epidermal bud can trigger granule release. This phenomenon can be induced by the subcutaneous injection of epinephrine, but the high and distressing dose needed to provoke appreciable changes in venom glands renders unlikely any natural intense venom release triggered by epinephrine in the frog.

  9. Acid exposure is an immune disruptor in adult Rana pipiens.

    Science.gov (United States)

    Vatnick, Itzick; Andrews, Jaime; Colombo, Matthew; Madhoun, Hareth; Rameswaran, Muthuramanan; Brodkin, Marc A

    2006-01-01

    Acidic environments are physiological stressors for amphibians. The objective of the present study was to document the effect of an acidic environment on innate immune system function under controlled experimental conditions in Rana pipiens. We developed an in vivo assay, by injecting a suspension of 1-microm fluorescent beads in fluid thioglycollate, to induce peritonitis. The number of peritoneal exudate leukocytes and their phagocytic activity did not increase with thioglycollate injection when frogs were exposed to pH 5.5 compared to when frogs were exposed to pH 7.0. An environment of pH 5.5 disrupted the inflammatory response of frogs compared to an environment of pH 7.0; at pH 5.5, more nonphagocytic leukocytes and fewer highly phagocytic leukocytes were found compared to those in frogs exposed to pH 7.0. Frogs stimulated by thioglycollate injection and exposed to pH 5.5 had a 50% increase in cells that did not exhibit phagocytosis and a 4- to 10-fold reduction in the number of highly phagocytic cells. This is evidence that acid exposure functions as an immune disruptor in adult R. pipiens under laboratory conditions.

  10. Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802

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    M. J. Costa

    Full Text Available Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage is affected by their acute exposure (48 h to a sub-lethal concentration (10 µg.L–1 of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP. Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.

  11. Complete mitochondrial genome of a brown frog, Rana kunyuensis (Anura: Ranidae).

    Science.gov (United States)

    Li, Jiao; Yin, Wei; Xia, Rong; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

    The first complete mitochondrial genome (mitogenome) of Rana sensu stricto (sensu Frost, 2013) was determined using Rana kunyuensis as a representative species. The mitogenome was 22,255 bp in length, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and duplicated control regions. The mitogenome of R. kunyuensis showed novel gene order arrangement with a translocation of tRNA(Leu)((CUN)) and ND5 in comparison with published anuran mitogenomes to date. This mitogenome should contribute to understand the evolution of anuran mitochondrial gene order arrangements.

  12. Chromosome Aberrations of East Asian Bullfrog (Hoplobatrachus rugulosus around a Gold Mine Area with Arsenic Contamination

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    Atidtaya Suttichaiya

    2016-01-01

    Full Text Available The objectives of this study are to investigate the chromosome aberrations of the East Asian Bullfrog (Hoplobatrachus rugulosus in the gold mine area compared to an unaffected area. Three H. rugulosus were collected, and chromosome aberrations were studied using bone marrow. The level of arsenic was measured in water, sediment and H. rugulosus samples. The average concentrations of arsenic in the water and sediment samples from the gold mine and unaffected areas were 0.03 ± 0.003 mg/l and not detected in water as well as 351.59 ± 5.73 and 1.37 ± 1.07 mg/kg in sediment, respectively. The gold mine values were higher than the permissible limit of the water and soil quality standards, but the arsenic concentrations in the samples from the unaffected area were within prescribed limit. The average concentrations of arsenic in H. rugulosus samples from the gold mine and unaffected areas were 0.39 ± 0.30 and 0.07 ± 0.01 mg/kg, respectively, which were both lower than the standard of arsenic contamination in food. The diploid chromosome number of H. rugulosus in both areas was 2n=26, and the percentage of chromosome breakages of H. rugulosus in the gold mine area were higher than the unaffected area. There were eight types of chromosome aberrations, including a single chromatid gap, isochromatid gap, single chromatid break, isochromatid break, centric fragmentation, deletion, fragmentation and translocation. The most common chromosome aberration in the samples from the affected area was deletion. The difference in the percentage of chromosome breakages in H. rugulosus from both areas was statistically significant (p<0.05.

  13. Alterações histopatológicas em girinos de rã-touro alimentados com rações comerciais de diferentes níveis protéicos Histopathological alterations in bullfrog tadpoles fed commercial diets with three levels of crude protein

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    José Teixeira de Seixas Filho

    2008-12-01

    Full Text Available Realizaram-se necropsia e exame histopatológico de girinos de rã-touro (Rana catesbeiana alimentados com rações comerciais formuladas com 32, 36, 45 ou 55% de proteína bruta (PB visando estabelecer a relação entre o nível de proteína bruta da ração e a sanidade do animal. Na necropsia, os girinos não apresentaram externamente nenhuma alteração aparente, no entanto, o fígado dos animais, em todos os níveis de proteína bruta, apresentou-se de cor palha e manchado. Na análise histopatológica, observaram-se fígados com rarefação e degeneração celular protéica, intestinos com colite e achatamento das microvilosidades; baço com hiperplasia linfocitária; coração sem nenhuma alteração; rins com glomerulonefrite e áreas de tubulonefroses; gastrite mononuclear e hiperplasia e hipertrofia dos linfonodos regionais. Em todos os órgãos, verificou-se depósito de hemossiderina. Essas lesões sugerem quadro degenerativo nutricional, com desenvolvimento de processos inflamatórios, se difundindo para todos os órgãos. Os resultados sugerem que os animais foram alimentados com rações com proteínas de baixo valor biológico, portanto, de má qualidade, o que comprometeu a sanidade e o desempenho dos animais. Estudos complementares são necessários para compreensão do comportamento bioquímico de rãs-touro na fase de girino visando à nutrição adequada desses animais.Necropsy and histological examination were made on bullfrog (Rana catesbeiana tadpoles fed commercial rations with 32, 36, 45 or 55% crude protein (CP to establish the relationship between dietary crude protein and health of the animal. In the necropsy, the tadpoles did not show externally any changes, however, the liver of animals at all crude protein levels, presented a straw color and stained. Histological analysis showed livers with rarefaction and degeneration of cell protein, intestines, with colitis and flattening of microvilli, spleen with lymphocyte

  14. Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

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    Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

    2006-01-01

    We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

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

    Science.gov (United States)

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

    2005-01-01

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

  16. Behavioural consistency and life history of Rana dalmatina tadpoles.

    Science.gov (United States)

    Urszán, Tamás János; Török, János; Hettyey, Attila; Garamszegi, László Zsolt; Herczeg, Gábor

    2015-05-01

    The focus of evolutionary behavioural ecologists has recently turned towards understanding the causes and consequences of behavioural consistency, manifesting either as animal personality (consistency in a single behaviour) or behavioural syndrome (consistency across more behaviours). Behavioural type (mean individual behaviour) has been linked to life-history strategies, leading to the emergence of the integrated pace-of-life syndrome (POLS) theory. Using Rana dalmatina tadpoles as models, we tested if behavioural consistency and POLS could be detected during the early ontogenesis of this amphibian. We targeted two ontogenetic stages and measured activity, exploration and risk-taking in a common garden experiment, assessing both individual behavioural type and intra-individual behavioural variation. We observed that activity was consistent in all tadpoles, exploration only became consistent with advancing age and risk-taking only became consistent in tadpoles that had been tested, and thus disturbed, earlier. Only previously tested tadpoles showed trends indicative of behavioural syndromes. We found an activity-age at metamorphosis POLS in the previously untested tadpoles irrespective of age. Relative growth rate correlated positively with the intra-individual variation of activity of the previously untested older tadpoles. In previously tested older tadpoles, intra-individual variation of exploration correlated negatively and intra-individual variation of risk-taking correlated positively with relative growth rate. We provide evidence for behavioural consistency and POLS in predator- and conspecific-naive tadpoles. Intra-individual behavioural variation was also correlated to life history, suggesting its relevance for the POLS theory. The strong effect of moderate disturbance related to standard behavioural testing on later behaviour draws attention to the pitfalls embedded in repeated testing.

  17. Liver histopathological changes in breeding bullfrogs - doi: 10.4025/actascibiolsci.v35i4.15981

    Directory of Open Access Journals (Sweden)

    José Teixeira de Seixas Filho

    2013-07-01

    Full Text Available In order to complement the histopathological study of juveniles and tadpoles of the bullfrog, Lithobathes catesbeianus, fed commercial diet used by frog farms in Rio de Janeiro, containing 40% crude protein, we performed necropsy and histopathology of the liver to establish a relationship between the quality of crude protein in the diet and animal health. For this, it was used twenty breeding male bullfrogs, with average weight 591.30 g (± 91.90 g and length 165.02 mm (± 14.22 mm, and ten females with average weight and length of 629.80 g (± 134.47 g and 169.32 mm (± 21.82 mm. The liver histopathology showed hyperemia, high number of melanomacrophages and cytoplasmic rarefaction, probably due to protein deficiency and fatty liver degeneration and presence of inflammatory processes. These lesions indicate a degenerative nutritional process. These findings suggest that the animals were fed with proteins of low biological value, indicating poor quality of feed, undermining the sanity. The impairment of liver function by these injuries will lead to reduced availability of precursors of sex hormones, since the liver is important in the metabolism of the same, and reproductive performance of these animals may be impaired.

  18. Stimulatory effects of zinc oxide nanoparticles on visual sensitivity and electroretinography b-waves in the bullfrog eye.

    Science.gov (United States)

    Wahid, Fazli; Ul-Islam, Mazhar; Khan, Romana; Khan, Taous; Khattak, Waleed Ahmad; Hwang, Kyung-Hee; Park, Jong Seok; Chang, Su-Chan; Kim, You Young

    2013-08-01

    During the last decade, a large number of studies have focused on the development of nanomaterials for medical applications. Therefore, the present study was designed to evaluate the stimulatory effects of zinc oxide nanoparticles in the vertebrate visual system. Zinc oxide nanoparticles were synthesized and characterized through photoluminescence, ultraviolet (UV)-visible spectroscopy, field emission scanning electron microscopy and X-ray diffraction measurements. Furthermore, various electrophysiological recordings were obtained from the bullfrog eyecup preparations under various treatment conditions. Photoluminescence data showed a central peak at 386 nm while the UV-visible spectrum showed a sharp absorption band centered around 367 nm. Field emission scanning electron microscopy and X-ray diffraction measurements showed that synthesized zinc oxide nanoparticles have a polycrystalline wurtzite structure, with a round to oval shape and an average particle size of > 40 nm. Electroretinography (ERG) demonstrated that zinc oxide nanoparticles significantly increased the ERG b-wave amplitude in dark-adapted bullfrog eyecups and in the presence of background illumination. Zinc oxide nanoparticles also improved the visual sensitivity by 0.7 log unit of light intensity and shortened the duration of rhodopsin regeneration. Based on the results obtained, it was concluded that zinc oxide nanoparticles may be used to improve visual functions. The present study may add new dimensions to the biomedical applications of nanomaterials in eye research.

  19. Valores fisiológicos en sangre y orina de rana toro en cautiverio, rana catesbeiana (Anura: ranidae)

    OpenAIRE

    Coppo, J. A.; N.B. Mussart; Fioranelli, S. A.; Zeinsteger, Pedro Adolfo

    2005-01-01

    Con el propósito de obtener valores sanguíneos y urinarios de referencia, 302 muestras de ejemplares sanos de Rana catesbeiana del nordeste argentino (9-21 meses de edad, 50% de cada sexo), fueron analizadas por espectrofotometría, electroforesis, densitometría, refractometría y microscopía. Fueron obtenidos intervalos de confianza (p

  20. Valores fisiológicos en sangre y orina de rana toro en cautiverio, rana catesbeiana (Anura: ranidae)

    OpenAIRE

    Coppo, J. A.; Mussart, N. B.; Fioranelli, S. A.; Zeinsteger, Pedro Adolfo

    2005-01-01

    Con el propósito de obtener valores sanguíneos y urinarios de referencia, 302 muestras de ejemplares sanos de Rana catesbeiana del nordeste argentino (9-21 meses de edad, 50% de cada sexo), fueron analizadas por espectrofotometría, electroforesis, densitometría, refractometría y microscopía. Fueron obtenidos intervalos de confianza (p

  1. Analysis of Conservative Tracer Tests in the Bullfrog, Tram, and Prow Pass Tuffs, 1996 to 1998, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Umari, Amjad; Fahy, Michael F.; Earle, John D.; Tucci, Patrick

    2008-01-01

    To evaluate the potential for transport of radionuclides in ground water from the proposed high-level nuclear-waste repository at Yucca Mountain, Nevada, conservative (nonsorbing) tracer tests were conducted among three boreholes, known as the C-hole Complex, and values for transport (or flow) porosity, storage (or matrix) porosity, longitudinal dispersivity, and the extent of matrix diffusion were obtained. The C-holes are completed in a sequence of Miocene tuffaceous rock, consisting of nonwelded to densely welded ash-flow tuff with intervals of ash-fall tuff and volcaniclastic rocks, covered by Quaternary alluvium. The lower part of the tuffaceous-rock sequence includes the Prow Pass, Bullfrog, and Tram Tuffs of the Crater Flat Group. The rocks are pervaded by tectonic and cooling fractures. Paleozoic limestone and dolomite underlie the tuffaceous rocks. Four radially convergent and one partially recirculating conservative (nonsorbing) tracer tests were conducted at the C-hole Complex from 1996 to 1998 to establish values for flow porosity, storage porosity, longitudinal dispersivity, and extent of matrix diffusion in the Bullfrog and Tram Tuffs and the Prow Pass Tuff. Tracer tests included (1) injection of iodide into the combined Bullfrog-Tram interval; (2) injection of 2,6 difluorobenzoic acid into the Lower Bullfrog interval; (3) injection of 3-carbamoyl-2-pyridone into the Lower Bullfrog interval; and (4) injection of iodide and 2,4,5 trifluorobenzoic acid, followed by 2,3,4,5 tetrafluorobenzoic acid, into the Prow Pass Tuff. All tracer tests were analyzed by the Moench single- and dual-porosity analytical solutions to the advection-dispersion equation or by superposition of these solutions. Nonlinear regression techniques were used to corroborate tracer solution results, to obtain optimal parameter values from the solutions, and to quantify parameter uncertainty resulting from analyzing two of the three radially convergent conservative tracer tests

  2. Distribution of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwestern USA

    Science.gov (United States)

    Pearl, Christopher A.; Bull, E.L.; Green, D.E.; Bowerman, Jay; Adams, Michael J.; Hyatt, A.; Wente, W.

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and we found a?Y 1 detection of B. dendrobatidis from 43% of sites. Four of seven species tested positive for B. dendrobatidis, including the Northern Red-Legged Frog (Rana aurora), Columbia Spotted Frog (Rana luteiventris), and Oregon Spotted Frog (Rana pretiosa). We also detected B. dendrobatidis in nonnative American Bullfrogs (Rana catesbeiana) from six sites in western and central Oregon. Our study and other recently published findings suggest that B. dendrobatidis has few geographic and host taxa limitations among North American anurans. Further research on virulence, transmissibility, persistence, and interactions with other stressors is needed to assess the potential impact of B. dendrobatidis on Pacific Northwestern amphibians.

  3. The response characteristics of vibration-sensitive saccular fibers in the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1988-01-01

    The response characteristics of saccular nerve fibers in European grassfrogs (Rana temporaria) subjected to dorso-ventral, 10-200 Hz sinusoidal vibrations were studied. Only 4 fibers out of a total of 129 did not respond to the vibrations. 70 fibers had an irregular spontaneous activity of 2...

  4. Oregon spotted frog (Rana pretiosa) monitoring at Jack Creek 2015-2016

    Science.gov (United States)

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

    2017-01-01

    This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort at Jack Creek, Klamath County, Oregon. Data consist of spotted frog counts aggregated by date, location, life stage, and sex, as well as data on environmental conditions at the time each survey.

  5. Leech presence on Iberian Brown Frog, Rana iberica, (Amphibia: Anura: Ranidae from north-western Spain

    Directory of Open Access Journals (Sweden)

    César Ayres

    2008-12-01

    Full Text Available The authors describe a case of parasitism on Rana iberica by two species of leeches, Batracobdella sp. and Hirudo medicinalis, in a mountainous area of north-western Spain. Conservation implications of high parasite load on small and isolated populations are discussed.

  6. Acid-base regulation in tadpoles of Rana catesbeiana exposed to environmental hypercapnia

    DEFF Research Database (Denmark)

    Busk, Morten; Larsen, Erik Hviid; Jensen, Frank B.

    1997-01-01

    Tadpoles of Rana catesbeiana were exposed to different levels of environmental hypercapnia. The acid-base regulatory response differed from that in adult amphibians in showing a high degree of pH compensation in the extracellular fluid (65-85%) and complete compensation in the intracellular fluid...

  7. Blood and urine physiological values in farm-cultured Rana catesbeiana (Anura: Ranidae) in Argentina

    OpenAIRE

    2014-01-01

    A total of 302 samples of healthy farm-cultured Rana catesbeiana specimens (9-21 months-old, 50- 350 g liveweight, 50% each sex) from the north-east of Argentina, were analyzed through spectrophotometry, electrophoresis, densitometry, refractometry and microscopy in order to obtain blood and urine normal values. Confidence intervals (p

  8. Pattern formation in artificially activated ectoderm (Rana pipiens and Ambystoma punctatum)

    NARCIS (Netherlands)

    Nieuwkoop, P.D.

    1963-01-01

    Presumptive ectoneuroderm of late blastulae or early gastrulae of Rana pipiens was partially activated by short-lasting disaggregation in Ca-free Holtfreter or Niu-Twitty solutions and subsequent reaggregation in normal solutions. The explants usually became dumbbell shaped and consisted respectivel

  9. The collapse of Rana Plaza and the limits, options and challenges of transnational labour regulation

    NARCIS (Netherlands)

    ter Haar, B.

    2013-01-01

    The collapse of the Rana Plaza in Bangladesh on 24 April 2013 resulted in the death of over 1,100 workers and many more injured workers. Consequently, it has again raised the debate about the social responsibility of multinational companies (MNCs) for their full production chain. European and

  10. Demography and movement in a relocated population of Oregon Spotted Frogs (Rana pretiosa): Influence of season and gender

    Science.gov (United States)

    Chelgren, N.D.; Pearl, C.A.; Adams, M.J.; Bowerman, J.

    2008-01-01

    We used five years of recapture data and Bayesian estimation to assess seasonal survival, movement, and growth of Oregon Spotted Frogs (Rana pretiosa) relocated into created ponds at Dilman Meadow in Oregon, USA. We evaluate hypotheses specific to the relocation and elucidate aspects of R. pretiosa life history that are poorly known. The odds of survival of relocated individuals during the first year following relocation were 0.36 times the survival odds of relocated and non-relocated frogs after one year since the relocation. Survival rate was higher for large frogs. After accounting for frog size, we found little variation in survival between ponds at Dilman Meadow. Survival was lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. The highest survival rates occurred during winter for both genders, and one small spring was used heavily during winter but was used rarely during the rest of the year. Individual growth was higher in ponds that were not used for breeding, and increased with increasing pond age. Our study supports other evidence that R. pretiosa use different habitats seasonally and are specific in their overwintering habitat requirements. Because frogs were concentrated during winter, predator-free overwintering springs are likely to be of particular value for R. pretiosa populations. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

  11. Altitudinal variation in body size and age structure of the Sauter’s frog Rana sauteri in Taiwan

    National Research Council Canada - National Science Library

    Hsu, Fu-Hsiung; Hsieh, Yi-Shan; Wu, Sheng-Hai; Kam, Yeong-Choy

    2014-01-01

    .... Altitudinal variations in body size, age, and growth rate of the Sauter’s frog Rana sauteri were investigated with skeletochronology at six sites along the altitudinal gradients from 330 to 2,320...

  12. Cocaine- and amphetamine-regulated transcript (CART) peptide as an in vivo regulator of cardiac function in Rana ridibunda frog

    National Research Council Canada - National Science Library

    Iliyana V. Ivanova; Rudolf Schubert; Dessislava B. Duridanova; Thomas B. Bolton; Lubomir T. Lubomirov; Hristo S. Gagov

    2007-01-01

    The aim of this study was to investigate the effect of CART peptide on cardiac performance and on the physiological signalling pathways involved using Rana ridibunda frog heart preparations in vivo...

  13. [Involution of gonadotrophic cells of the pituitary gland in the male frog, Rana esculenta, after section of the pituitary stem].

    Science.gov (United States)

    Legait, H; Helas, G

    1976-01-01

    One and two months after section of the hypophyseal stalk in the male frog. Rana esculenta, and involution of numerous gonadotrophic cells, contrasting with the normal aspect of the eosinophilic cells can be observed.

  14. Peripheral origins and functional characteristics of vibration-sensitive VIIIth nerve fibers in the frog Rana temporaria

    DEFF Research Database (Denmark)

    Jøgensen, Morten Buhl; Christensen-Dalsgaard, Jakob

    1991-01-01

    1) The peripheral origins of vibration-sensitive VIIIth nerve fibers in European grassfrogs (Rana temporaria) were investigated by recording from individual nerve branchlets within the inner ear. Furthermore, the fibers' responses to both pulsed and continuous, dorsoventral, sinusoidal vibrations...

  15. Community Structure and Function of Amphibian Skin Microbes: An Experiment with Bullfrogs Exposed to a Chytrid Fungus.

    Directory of Open Access Journals (Sweden)

    Jenifer B Walke

    Full Text Available The vertebrate microbiome contributes to disease resistance, but few experiments have examined the link between microbiome community structure and disease resistance functions. Chytridiomycosis, a major cause of amphibian population declines, is a skin disease caused by the fungus, Batrachochytrium dendrobatidis (Bd. In a factorial experiment, bullfrog skin microbiota was reduced with antibiotics, augmented with an anti-Bd bacterial isolate (Janthinobacterium lividum, or unmanipulated, and individuals were then either exposed or not exposed to Bd. We found that the microbial community structure of individual frogs prior to Bd exposure influenced Bd infection intensity one week following exposure, which, in turn, was negatively correlated with proportional growth during the experiment. Microbial community structure and function differed among unmanipulated, antibiotic-treated, and augmented frogs only when frogs were exposed to Bd. Bd is a selective force on microbial community structure and function, and beneficial states of microbial community structure may serve to limit the impacts of infection.

  16. Respiration and hemoglobin function in the giant African bullfrog Pyxicephalus adspersus Tschudi (Anura: Pyxicephalidae) during rest, exercise and dormancy

    DEFF Research Database (Denmark)

    van Aardt, W.J; Weber, Roy E.

    2010-01-01

    of dormancy in soil without forming cocoons. With virtually no information available on the associated respiratory adaptations, we measured oxygen consumption rates of resting and exercising bullfrogs together with haematological and gas-binding properties of blood and haemoglobin (Hb) solutions from non......-dormant frogs and cocoon-less dormant frogs. Treadmill (0.054 ms-1) exercising frogs consumed nearly seven times more oxygen than resting individuals (8.45 and 1.25 mmol O2 kg-1h-1, respectively). During a six-month dormancy period Pyxicephalus lost an average of 13.7% of its body mass, while plasma osmotic...... oxygen affinity, the affinity of 'stripped' (cofactor-free) Pyxicephalus Hb shows low sensitivity to this effector. Hb-oxygen affinity is moreover insensitive to Cl- ions (that depress O2 affinity of most vertebrate haemoglobins) but oxygen affinity is strongly increased by urea and metHb formation...

  17. Profile of cortisol, glycaemia, and blood parameters of American Bullfrog tadpoles Lithobates catesbeianus exposed to density and hypoxia stressors

    Directory of Open Access Journals (Sweden)

    Patricia C. Teixeira

    2012-12-01

    Full Text Available The aim of this study was to evaluate alterations to the physiological profile (cortisol, glycaemia, and blood parameters of Lithobates catesbeianus caused by the stressors density and hypoxia. The organisms were in the prometamorphosis stage and exposed to different tadpole densities: 1 tadpole/L (T1, 5 tadpoles/L (T2, and 10 tadpoles/L (T3 for 12 days. The blood was collected through the rupture of the caudal blood vessel and collected under normoxia (immediate collection and hypoxia (after 15 minutes of air exposure conditions. Cortisol levels rose on the fourth and eighth days of treatment and returned to basal levels by the end of the experiment. The stressor mechanisms tested did not affect glycaemia. White blood cells (total number of lymphocytes, neutrophils, and eosinophils showed a significant difference at the twelfth day of the experiment when compared with the start of the experiment. We concluded that, under controlled conditions, a density of up to 10 tadpoles/L and air exposure for 15 minutes did not cause harmful physiological alterations during the experimental period. The answer to these stressors maybe was in another hormonal level (corticosterone.

  18. discussion on validity of rana maoershanensis based on partial sequence of 16s rrna gene

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    rana maoershanensis found in mt.maoershan in guangxi,china was reported as a new species in 2007,but there was no molecular data for this frog.the partial sequences (543 bp) of 16s rrna gene from 12 specimens of 3 brown frog species (rana hanluica,r.maoershanensis and r.chensinensis) were analyzed with 17 specimens of 9 species from genbank.the nucleotide sequence divergence between r.maoershanensis and the other brown frog species were 4.5%-6.5%,with 22-30 nucleotide substitutions at this locus.the phylogenetic relationships based on mp,ml,and bayesian inference indicate that the brown frogs from southern china were diverged into three groups (clades a,b and c).r.maoershanensis was clustered together a well-supported subclade (b-l).it is suggested that r.maoershanensis is a valid species.

  19. 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.

  20. N.C. Rana: The Life of a `Comet' in the Astrophysical World

    CERN Document Server

    Mukhopadhyay, Utpal

    2014-01-01

    Narayan Chandra Rana, a person with extraordinary potential from a remote village of Bengal, India, came into the limelight of the international scientific world through his exceptional talent, zeal and courage. In his very short life-span, he excelled not only into various branches of astrophysics, but also took a leading role in science popularization, text book writing etc. In this paper, life and works of that budding scientist of India have been discussed from multifarious viewpoints.

  1. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

    OpenAIRE

    Merilä Juha; Miura Ikuo; Matsuba Chikako

    2008-01-01

    Abstract Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determinat...

  2. Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager; Fog, Kåre; Pedersen, Bo Vest;

    2005-01-01

    All-hybrid populations of the water frog, Rana esculenta, are exceptional in consisting of independently and to some extent sexually reproducing interspecific hybrids. In most of its range R. esculenta reproduces hemiclonally with one of the parental species, R. lessonae or R. ridibunda, but viable...... gametogenesis and mating between frogs with incompatible gametes induce a significant hybrid load in all-hybrid populations of R. esculenta, and we discuss compensating advantages and potential evolutionary trajectories to reduce this hybrid load....

  3. Effects of Inactivated Streptococcus Aglactiae Vaccineon Immunity in Bullfrog%牛蛙源无乳链球菌全菌疫苗免疫效果研究

    Institute of Scientific and Technical Information of China (English)

    周冬仁; 陈莎莎; 杭小英; 施伟达; 罗毅志; 叶雪平

    2012-01-01

    将分离鉴定的无乳链球菌用0.4%的甲醛灭活,加弗氏完全佐剂制成灭活全菌苗,对牛蛙进行注射免疫.通过测定受免牛蛙血清中凝集抗体效价,总蛋白、免疫球蛋白的测定及免疫保护率的测定,探讨疫苗的免疫应答状况.研究结果表明,无乳链球菌全菌疫苗能够提高牛蛙的血清抗体水平及总蛋白、免疫球蛋白含量.此外,无乳链球菌全菌苗对牛蛙抗人工感染也具有较好的免疫保护作用,其免疫保护率为67%.因此,将无乳链球菌全菌苗用于牛蛙链球菌病的防治具有广阔的发展前景.%The isolated and identified Streptococcus agalactiae inactivated with 0.4% formaldehyde, made inactivated whole bacteria vaccine with CFA, immunity Bullfrog by injections. By measuring serum agglutinate titer, total protein, the determination of immunoglobulin and immune protection rate, determinate of status of the vaccine immune response. The results showed that all bacteria vaccine can improve the bullfrog serum antibody levels and total protein, immunoglobulin content. In addition, all bacteria vaccine infected bullfrog also has good resistance to the immune protective effects on the immune protection rate. Therefore, there is a potential to apply whole bacteria Streptococcus agalactiae to prevention and cure of Bullfrog suffering with Streptococcus agalactiae.

  4. Avaliação histológica do intestino médio, do fígado e do pâncreas de girinos de rã-touro alimentados com rações comerciais formuladas com três níveis de proteína bruta Histological evaluation of midgut, liver and pancreas of bullfrog tadpoles fed commercial diets with three levels of crude protein

    Directory of Open Access Journals (Sweden)

    José Teixeira de Seixas Filho

    2008-12-01

    Full Text Available Avaliou-se o desenvolvimento do intestino médio, do fígado e do pâncreas de girinos de rã-touro (Rana catesbeiana alimentados com ração comercial com 22, 24 ou 28% de proteína bruta (PB. Utilizaram-se 360 girinos com 15 dias de vida, provenientes de mesma desova, distribuídos em caixas com 30 L de água, em densidade de 1 girino/L, mantidas a 25°C (±1ºC, constituindo um delineamento experimental completamente casualizado, com quatro repetições. A partir do 9º dia e até o 48º dia de alimentação, os órgãos (intestino médio, fígado e pâncreas de três girinos de cada grupo foram fixados em solução histológica de Bouin para coloração por hematoxilina e eosina. A presença de tecido conjuntivo extremamente frouxo nas alças intestinais dos girinos sugeriu situação provisória para a mudança da arquitetura intestinal após a metamorfose. Nesse período, observou-se aumento no número de células caliciformes e de microvilosidades e, no 25º dia, verificou-se a presença de células hepáticas, com arranjo glandular mais compacto, o que sugere funcionalidade e confirma os melhores resultados de desempenho obtidos a partir desse período nos girinos alimentados com as rações com maior nível protéico. No 35º dia, observou-se a estrutura do fígado bilobado, com sinais de desorganização, o que indica rarefação celular protéica, decorrente de mau aproveitamento da proteína da ração. Novos estudos são necessários para continuidade aos esclarecimentos sobre as características fisiológicas de rãs-touro na fase de girino.The development of midgut, liver and pancreas bullfrog tadpoles (Rana catesbeiana fed commercial diets with 22, 24 or 28% of crude protein (CP was evaluated. A total of 360 tadpoles, 15 days old, from the same spawning, was allotted to 30 L-boxes, using a density of 1 tadpole/L, kept at 25 °C (±1°C. A completely randomized experimental design with four replications was used. Three tadpoles of

  5. O sufixo -rana no português falado pelo caboclo amazonense

    Directory of Open Access Journals (Sweden)

    Orlando Azevedo

    2012-12-01

    Full Text Available O artigo aborda a formação de palavras com o sufixo -rana no português falado em seis localidades situadas na região do Médio Solimões no Estado do Amazonas. O corpus para a análise foi retirado das respostas dos informantes ao questionário semântico-lexical da tese de Azevedo¹, que está em andamento e que trata da variação dialetal na região do Baixo Amazonas e do Médio Solimões. Para os propósitos da pesquisa, nossa fundamentação foi baseada no modelo da morfologia gerativa a fim de que fosse possível a construção de uma regra aplicável às bases que esse sufixo seleciona. Os resultados mostraram a existência de formações neológicas, uma vez que não foram encontradas em obras lexicográficas. Além disso, o sufixo -rana ao selecionar bases substantivas não muda a classe gramatical da palavra primitiva ao formar novos substantivos. Devido à regularidade, foi possível estabelecermos uma regra de formação de palavras para o sufixo -rana no português falado nessa região da Amazônia brasileira.

  6. Incongruence in the pattern and timing of intra-specific diversification in bronze frogs and bullfrogs (Ranidae).

    Science.gov (United States)

    Austin, James D; Zamudio, Kelly R

    2008-09-01

    We compare patterns of lineage divergence in mitochondrial DNA (mtDNA) sequences of two protein-encoding mitochondrial genes (cyt b and ND2) in two ecologically similar, co-distributed, and closely related ranid frogs (Rana clamitans and Rana catesbeiana), that are geographically widespread, and frequently syntopic. We identified three lineages in R. clamitans, separated by 0.5% to 2.1% net corrected sequence divergence, comparable to two R. catesbeiana lineages separated by 0.6%. The geographic pattern of lineage distribution differed notably between the two species. In R. clamitans, we found a Coastal Plain-Appalachian (CPA) lineage restricted to south and east of the Appalachian Mountains and a widespread lineage that encompassing nearly all the sampled range. A third distinct and divergent lineage was detected in one location in the southwest portion of the range (Louisiana). This pattern contrasts with the east-west pattern in R. catesbeiana, and reflects possible differences in refugial dynamics and patterns of range expansion. Although both species have undergone range expansion and population growth, coalescent reconstruction of N(e) reflects larger lineages but more recent divergence in R. clamitans relative to R. catesbeiana, reflecting significant differences in population history or divergent patterns of molecular evolution at mtDNA.

  7. 黑斑蛙、虎纹蛙和牛蛙皮肤的比较组织学%Comparative Histology of the Skin of Rana Nigromaculata,Rana Rugulosa and Rana Catesbeiana

    Institute of Scientific and Technical Information of China (English)

    李洋; 金磊; 李昌春; 唐宝将; 张盛周

    2009-01-01

    应用H.E和V.G胶原染色法对黑斑蛙(Rana nigromaculata)、虎纹蛙(Rana rugulosa)和牛蛙(Rana catesbeiana)皮肤进行了组织学观察和参数测量与比较.结果表明:三种蛙皮肤组织结构相似,但皮肤厚度、各组织层相对厚度及腺体密度存在较明显的种间差异和部位差异.虎纹蛙的皮肤最厚(0.44-0.68mm),牛蛙其次(0.28-0.60mm),黑斑蛙最薄(0.19-0.38mm);在三种蛙中,黑斑蛙躯体多数部位表皮相对厚度为15.1%-22.6%,较虎纹蛙(10.9%-17.7%)和牛蛙(9.9%-21.8%)厚.虎纹蛙和牛蛙皮肤胶原纤维层相对厚度分别为59.9%-68.7%和51.6%-75.3%,较黑斑蛙(44.4%-69.0%)厚;黑斑蛙和虎纹蛙躯体多数部位的颗粒腺密度(4.5-23.1个/mm2;8.9-25.3个/mm2)和粘液腺(54.1-152.2个/mm2;68.6-127.5个/mm2)较牛蛙(1.4-10.8个/mm2;16.8-39.3个/mm2)高.研究结果可供蛙类皮肤的合理开发利用参考.

  8. Lesiones histológicas en músculo esquelético, causadas por larvas de Eustrongylides sp (Nematoda: Dictophymatidae) en ranas comestibles del Lago Cuitzeo, Michoacán, México

    OpenAIRE

    José Ramírez Lezama; David Osorio Sarabia

    2002-01-01

    El presente estudio tiene como objetivo informar sobre las lesiones microscópicas provocadas por larvas de Eustrongylides sp en músculo esquelético de ranas en el Lago Cuitzeo, Michoacán, México, considerado un parásito potencialmente zoonótico. Se revisaron 146 ejemplares de las cuatro especies: 80 de Rana megapoda, 43 de Rana dunni, 16 de Rana catesbiana y siete de Rana verlandieri, a los cuales se le aplicó la eutanasia con sobredosis de pentobarbital por vía intraperitoneal. Se registró e...

  9. Complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae): comparison of R. chosenica and R. plancyi.

    Science.gov (United States)

    Ryu, Shi Hyun; Hwang, Ui Wook

    2011-06-01

    Here, we have sequenced the complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae), which is known as a Korean endemic species. It is listed as a vulnerable species by IUCN Red List and also an endangered species in South Korea. The complete mitochondrial genome of R. chosenica consists of 18,357 bp. Its gene arrangement pattern was identical with those of other Rana frogs. We compared the mitochondrial genome of R. chosenica with that of the Peking frog Rana plancyi that has been known closely related to R. chosenica. Nucleotide sequence similarity between the two whole mitochondrial genomes was 95.7%, and the relatively low similarity seems to indicate that the two species are distinctly separated on the species level. The information of mitochondrial genome comparison of the two species was discussed in detail.

  10. Spatiotemporal Diversification of the True Frogs (Genus Rana): A Historical Framework for a Widely Studied Group of Model Organisms.

    Science.gov (United States)

    Yuan, Zhi-Yong; Zhou, Wei-Wei; Chen, Xin; Poyarkov, Nikolay A; Chen, Hong-Man; Jang-Liaw, Nian-Hong; Chou, Wen-Hao; Matzke, Nicholas J; Iizuka, Koji; Min, Mi-Sook; Kuzmin, Sergius L; Zhang, Ya-Ping; Cannatella, David C; Hillis, David M; Che, Jing

    2016-09-01

    True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and three mitochondrial loci sampled from most species of Rana, and use that phylogeny to clarify the group's diversification and global biogeography. Our analyses consistently support an "Out of Asia" pattern with two independent dispersals of Rana from East Asia to North America via Beringian land bridges. The more species-rich lineage of New World Rana appears to have experienced a rapid radiation following its colonization of the New World, especially with its expansion into montane and tropical areas of Mexico, Central America, and South America. In contrast, Old World Rana exhibit different trajectories of diversification; diversification in the Old World began very slowly and later underwent a distinct increase in speciation rate around 29-18 Ma. Net diversification is associated with environmental changes and especially intensive tectonic movements along the Asian margin from the Oligocene to early Miocene. Our phylogeny further suggests that previous classifications were misled by morphological homoplasy and plesiomorphic color patterns, as well as a reliance primarily on mitochondrial genes. We provide a phylogenetic taxonomy based on analyses of multiple nuclear and mitochondrial gene loci. [Amphibians; biogeography; diversification rate; Holarctic; transcontinental dispersal. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae)

    OpenAIRE

    Hernández-Guzmán, Javier; Arias-Rodriguez, Lenin; Rimber Indy, Jeane

    2010-01-01

    La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundame...

  12. O SUFIXO -RANA NO PORTUGUÊS FALADO PELO CABOCLO AMAZONENSE

    Directory of Open Access Journals (Sweden)

    Orlando Azevedo

    2012-01-01

    Full Text Available O artigo aborda a formação de palavras com o sufixo –rana no português falado em seis localidades situadas na região do Médio Solimões no Estado do Amazonas. O corpus para a análise foi retirado das respostas dos informantes ao questionário semântico-lexical da tese de Azevedo, que está em andamento e que trata da variação dialetal na região do Baixo Amazonas e do Médio Solimões. Para os propósitos da pesquisa, nossa fundamentação foi baseada no modelo da morfologia gerativa a fim de que fosse possível a construção de uma regra aplicável às bases que esse sufixo seleciona. Os resultados mostraram a existência de formações neológicas, uma vez que não foram encontradas em obras lexicográficas. Além disso, o sufixo –rana ao selecionar bases substantivas não muda a classe gramatical da palavra primitiva ao formar novos substantivos. Devido à regularidade, foi possível estabelecermos uma regra de formação de palavras para o sufixo –rana no português falado nessa região da Amazônia brasileira.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. [Serotonin and neuropeptide FMRFamide in the nervous system of Opisthioglyphe ranae (Trematoda: Plagiorchiidae). an immunocytochemical study].

    Science.gov (United States)

    Terenina, N B; Kreshchenko, N D; Chilyuta, N V; Zaripova, F F

    2015-01-01

    The presence and localization of the serotoninergic and FMRFamidergic structures in the nervous system of the trematode Opisthioglyphe ranae, the marsh frog intestinal parasite, was studied using immunocytochemistry. The serotonin-immunoreactive nerve cells and fibers were revealed in the head ganglia, circular commissure, longitudinal nerve cords and their connective commissures, as well as around the oral and ventral suckers, oesophagus and genital pore. FMRF-specific immunoreactivity was observed in the head ganglia, longitudinal nerve cords and terminal parts of the reproductive system. The results obtained are discussed in light of the available data on the presence and functional significance of the above-mentioned neurotransmitters in trematodes.

  15. Acid-base regulation in tadpoles of Rana catesbeiana exposed to environmental hypercapnia

    DEFF Research Database (Denmark)

    Busk, Morten; Larsen, Erik Hviid; Jensen, Frank B.

    1997-01-01

    Tadpoles of Rana catesbeiana were exposed to different levels of environmental hypercapnia. The acid-base regulatory response differed from that in adult amphibians in showing a high degree of pH compensation in the extracellular fluid (65-85%) and complete compensation in the intracellular fluid......). It is suggested that the large bicarbonate efflux from the animal is a consequence of the dissolution of CaCO3 stores and the delayed adjustment of bicarbonate-retaining mechanisms. Re-exposure of tadpoles to hypercapnia after 1-3 weeks of normocapnic recovery only affected transepithelial fluxes of acid-base...

  16. Purification and in vitro Activity of an Antimicrobial Peptide from Skin of Rana Temporaria Chensinensis, David

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; MENG Qing-fan; XU Xue-song; TIAN Xiao-le; JIANG Fu-jia; LI Qing-shan; TENG Li-rong

    2007-01-01

    In this study, an antimicrobial component (RTCI) was purified from the skin of Rana temporaria chensinensis,David. Antimicrobial activities of RTCI against clinical multi-drug resistant bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureaus, Klebsiella oxytoca, Klebsiella pneumoniae, Enterococcus faecalis, and Proteus mirabilis were measured in vitro by means of minimal inhibitory concentration and time-kill studies.The results indicate that RTCI could inhibit the growth of these bacteria at a proper concentration and suggest that RTCI shows a better antimicrobial activity to Gram-negative bacterial strains than to Gram-positive bacterial strains.

  17. Oregon spotted frog (Rana pretiosa) monitoring in the Oregon Cascades 2012-2016

    Science.gov (United States)

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

    2017-01-01

    This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort in the Oregon Cascade Mountain Range. We surveyed 91 sites using a rotating frame design in the Klamath and Deschutes Basins, Oregon, which encompass most of the species' core extant range. Data consist of spotted frog counts aggregated by date, location, and life stage, as well as data on environmental conditions at the time of each survey.

  18. Data regarding the trophic spectrum of a population of Rana esculenta Complex from Bacau County

    Directory of Open Access Journals (Sweden)

    Daniel GHIURCA

    2006-05-01

    Full Text Available We analyzed the trophic spectrum of one population of Rana esculenta complex collected, placed close to the lake accumulation Bacău II. The most abundant prey taxons in the food of edible frog are species from Coleoptera order, followed by Hymenoptera and Diptera among insects and Aranee among spiders. We identified a great number of gregarious small species (Formicidae showing an opportunistic predator behavior of this frogs, using the sit and wait foraging behavior. The terrestrial preys prevail in comparison with aquatic organisms.

  19. Pond and landscape determinants of Rana dalmatina population sizes in a Romanian rural landscape

    Science.gov (United States)

    Hartel, Tibor; Nemes, Szilárd; Cogălniceanu, Dan; Öllerer, Kinga; Moga, Cosmin Ioan; Lesbarrères, David; Demeter, László

    2009-01-01

    Amphibians are good indicators of human impact, declining steadily worldwide. We explored the relationships between the ponds and nearby landscape parameters and population size of the Agile Frog ( Rana dalmatina), estimated from the number of egg masses, in a cultural landscape within the central section of Târnava Mare Basin, Romania. Forty-three permanent ponds were surveyed in a 2600 km 2 area. The average number of egg masses per pond was 211.13 (SD = 426.41). The egg mass number was significantly and positively related to the emergent aquatic macrophyte cover (its effect peaks at around 50%) and the green connecting corridors between the ponds and forests, and negatively related to the extent of nearby urban areas. The proximity of the forest (positive effect) and the presence of high traffic roads (negative effect) were highly correlated with green corridors and further eliminated from the model due to multicollinearity. Both these variables had significant effects when incorporated in univariate models and multivariate models without green corridors. Since a large part of our study area was currently declared as Natura 2000 site, there is an increased need for management proposals and conservation applications for biodiversity, including amphibians. Rana dalmatina is an important species for monitoring because it is common in the studied area and is suited for short surveys.

  20. Development Present Situation of Rana chensinensis and Its Research Progress%中国林蛙产品的开发现状与研究进展

    Institute of Scientific and Technical Information of China (English)

    刘仁杰; 孙旸; 王刚; 陈欢; 陈光

    2014-01-01

    中国林蛙具有很高的经济价值和药用价值。本文介绍了中国林蛙的种类、分布状况和林蛙产品研究进展及产品开发现状,同时探讨了我国林蛙产业现状及未来发展。%Rana chensinensis has a very high economic and medicinal value. Species of Rana chensinensis, its distribution, research progress and product development status were introduced, and Rana chensinensis industry present situation and prospects of development were discussed.

  1. Sound and vibration sensitivity of VIIIth nerve fibers in the frogs Leptodactylus albilabris and Rana pipiens pipiens

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Narins, P M

    1993-01-01

    1. Responses of 73 fibers to dorso-ventral vibration were recorded in the saccular and utricular branchlets of Rana pipiens pipiens using a ventral approach. The saccular branchlet contained nearly exclusively vibration-sensitive fibers (33 out of 36) with best frequencies (BFs) between 10 and 70...

  2. Response characteristics of vibration-sensitive neurons in the midbrain of the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1989-01-01

    European grassfrogs (Rana temporaria) were stimulated with pulsed sinusoidal, vertical vibrations (10-300 Hz) and the responses of 46 single midbrain neurons were recorded in awake, immobilized animals. Most units (40) had simple V-shaped excitatory vibrational tuning curves. The distribution of ...

  3. Immunohistochemical colocalization of 7B2 and 5HT in the neuroepithelial bodies of the lung of Rana temporaria.

    Science.gov (United States)

    Bodegas, M E; Montuenga, L M; Polak, J M; Sesma, P

    1993-07-01

    The neuroendocrine cell population of the lung of Rana temporaria has been studied by means of immunocytochemistry. Serotonin (5HT)- and polypeptide 7B2-immunoreactive neuroepithelial bodies have been observed in the epithelial lining of the lung. 5HT- but not 7B2-immunoreactive isolated endocrine cells have also been observed.

  4. Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis.

    NARCIS (Netherlands)

    Vos, C.C.; Chardon, P.

    1998-01-01

    1. The effects of habitat fragmentation on the distribution pattern of the moor frog Rana arvalis were investigated. Also, the possible isolation effects of the road network were taken into account. 2. Indications were found that habitat fragmentation partly explains the distribution pattern of the

  5. Effects of environmental and natural estrogens on vitellogenin production in hepatocytes of the brown frog (Rana temporaria)

    NARCIS (Netherlands)

    Rouhani Rankouhi, T.; Sanderson, J.T.; Holsteijn, van I.; Kooten, van P.; Bosveld, A.T.C.; Berg, van den M.

    2005-01-01

    The objective of this study was to investigate the ability of the natural estrogens and synthetic estrogens as well as the estrogen mimics to induce estrogen-receptor mediated vitellogenesis in primary hepatocytes of the brown frog (Rana temporaria). Based on EC50 values the following order was dete

  6. Highly complex mitochondrial DNA genealogy in an endemic Japanese subterranean breeding brown frog Rana tagoi (Amphibia, Anura, Ranidae).

    Science.gov (United States)

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro; Tanaka-Ueno, Tomoko

    2012-10-01

    The endemic Japanese frog Rana tagoi is unique among Holarctic brown frogs in that it breeds in small subterranean streams. Using mitochondrial 16S ribosomal RNA and NADH dehydrogenase subunit 1 genes, we investigated genealogical relationships among geographic samples of this species together with its relative R. sakuraii, which is also a unique stream breeder. These two species together form a monophyletic group, within which both are reciprocally paraphyletic. Rana tagoi is divided into two major clades (Clade A and B) that are composed of 14 genetic groups. Rana sakuraii is included in Clade A and split into two genetic groups, one of which forms a clade (Subclade A-2) with sympatric R. tagoi. This species-level paraphyly appears to be caused by incomplete taxonomy, in addition to introgressive hybridization and/or incomplete lineage sorting. Rana tagoi strongly differs from other Japanese anurans in its geographic pattern of genetic differentiation, most probably in relation to its unique reproductive habits. Taxonomically, R. tagoi surely includes many cryptic species.

  7. Complex patterns of geographic variation in heat tolerance and Hsp70 expression levels in the common frog Rana temporaria

    DEFF Research Database (Denmark)

    Sørensen, Jesper Givskov; Pekkonen, Minna; Lindgren, Beatrice

    2009-01-01

    1. We tested for geographical variation in heat tolerance and Hsp70 expression levels of Rana temporaria tadpoles along a 1500 km long latitudinal gradient in Sweden.   2. Temperature tolerance of the hatchling tadpoles did not differ among populations, but they tolerated stressful hot temperatures...

  8. Rana Plaza en de (on)macht van MNO's om maatschappelijk verantwoord te ondernemen over de landsgrenzen heen

    NARCIS (Netherlands)

    ter Haar, B.P.

    2013-01-01

    De instorting van kledingfabriek Rana Plaza in Bangladesh heeft een debat losgemaakt over de maatschappelijke verantwoordelijkheid van multinationale ondernemingen (MNO’s) voor hun gehele productieketen, maar in hoeverre zijn MNO’s eigenlijk in staat om deze verantwoordelijkheid ook daadwerkelijk

  9. 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...

  10. Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis.

    NARCIS (Netherlands)

    Vos, C.C.; Chardon, P.

    1998-01-01

    1. The effects of habitat fragmentation on the distribution pattern of the moor frog Rana arvalis were investigated. Also, the possible isolation effects of the road network were taken into account. 2. Indications were found that habitat fragmentation partly explains the distribution pattern of the

  11. Phylogeography of the arid-adapted Malagasy bullfrog, Laliostoma labrosum, influenced by past connectivity and habitat stability.

    Science.gov (United States)

    Pabijan, Maciej; Brown, Jason L; Chan, Lauren M; Rakotondravony, Hery A; Raselimanana, Achille P; Yoder, Anne D; Glaw, Frank; Vences, Miguel

    2015-11-01

    The rainforest biome of eastern Madagascar is renowned for its extraordinary biodiversity and restricted distribution ranges of many species, whereas the arid western region of the island is relatively species poor. We provide insight into the biogeography of western Madagascar by analyzing a multilocus phylogeographic dataset assembled for an amphibian, the widespread Malagasy bullfrog, Laliostoma labrosum. We find no cryptic species in L. labrosum (maximum 1.1% pairwise genetic distance between individuals in the 16S rRNA gene) attributable to considerable gene flow at the regional level as shown by genetic admixture in both mtDNA and three nuclear loci, especially in central Madagascar. Low breeding site fidelity, viewed as an adaptation to the unreliability of standing pools of freshwater in dry and seasonal environments, and a ubiquitous distribution within its range may underlie overall low genetic differentiation. Moreover, reductions in population size associated with periods of high aridity in western Madagascar may have purged DNA variation in this species. The mtDNA gene tree revealed seven major phylogroups within this species, five of which show mostly non-overlapping distributions. The nested positions of the northern and central mtDNA phylogroups imply a southwestern origin for all extant mtDNA lineages in L. labrosum. The current phylogeography of this species and paleo-distributions of major mtDNA lineages suggest five potential refugia in northern, western and southwestern Madagascar, likely the result of Pleistocene range fragmentation during drier and cooler climates. Lineage sorting in mtDNA and nuclear loci highlighted a main phylogeographic break between populations north and south of the Sambirano region, suggesting a role of the coastal Sambirano rainforest as a barrier to gene flow. Paleo-species distribution models and dispersal networks suggest that the persistence of some refugial populations was mainly determined by high population

  12. Comparison of diet, reproductive biology, and growth of the pig frog (Rana grylio) from harvested and protected areas of the Florida Everglades

    Science.gov (United States)

    Ugarte, C.A.; Rice, K.G.; Donnelly, M.A.

    2007-01-01

    Distinct differences in body size exist among three Rana grylio populations in areas of the Florida Everglades that differ in frog harvest pressure and hydroperiod. Frogs from two populations are harvested regularly throughout the year, while those in the third are protected from harvest. We compared seasonal and sex differences in diet, reproduction, and growth across these populations to examine life-history patterns. By volume, crayfish and anurans were the most abundant prey items for all adults across sites. Frogs from drier sites consumed more crayfish than frogs from the wettest site. Anurans were abundant in the diet during the wet season, while crayfish and fish were abundant during the dry season. More frogs with empty stomachs were captured during the wet season than the dry season. Feeding, growth, and fat deposition were greatest during the dry season across all sites. Although females were found in all reproductive stages throughout the year, the highest percentage of females had mature ova during the late dry season and spent ovaries during the early wet season. Individual patterns of growth were similar across all sites and matched historical growth data from the 1950s. Differences in body size among sites were most likely attributable to differential mortality (i.e., harvest pressure, predation) rather than to differences in food access or growth. ?? 2007 by the American Society of Ichthyologists and Herpetologists.

  13. Hepatic effects of the clomazone herbicide in both its free form and associated with chitosan-alginate nanoparticles in bullfrog tadpoles.

    Science.gov (United States)

    de Oliveira, Cristiane Ronchi; Fraceto, Leonardo Fernandes; Rizzi, Gisele Miglioranza; Salla, Raquel Fernanda; Abdalla, Fábio Camargo; Costa, Monica Jones; Silva-Zacarin, Elaine Cristina Mathias

    2016-04-01

    The use of agrochemicals in agriculture is intense and most of them could be carried out to aquatic environment. Nevertheless, there are only few studies that assess the effects of these xenobiotics on amphibians. Clomazone is an herbicide widely used in rice fields, where amphibian species live. Thus, those species may be threatened by non-target exposure. However, nanoparticles are being developed to be used as a carrier system for the agrochemicals. Such nanoparticles release the herbicide in a modified way, and are considered to be more efficient and less harmful to the environment. The aim of this study was to comparatively evaluate the effect of clomazone in its free form and associated with nanoparticles, in the liver of bullfrog tadpoles (Lithobates catesbeianus) when submitted to acute exposure for 96 h. According to semi-quantitative analysis, there was an increase in the frequency of melanomacrophage centres, in the accumulation of eosinophils and in lipidosis in the liver of experimental groups exposed to clomazone - in its free form and associated with nanoparticles - in comparison with the control group, and the nanotoxicity of chitosan-alginate nanoparticles. The increase of melanomacrophage centres in all exposed groups was significant (P clomazone herbicide and organic nanoparticles, which act as carriers of agrochemicals, on the bullfrog tadpole liver.

  14. A Brief Report on Biology of Johns' Frog (Rana johnsi Smith,1921) in China%Rana johnsi的生物学初探

    Institute of Scientific and Technical Information of China (English)

    李丕鹏; 陆宇燕

    2007-01-01

    从保护生物学角度对广西大瑶山Rana johnsi Smith,1921的栖息地和繁殖地生境、繁殖生物学及蝌蚪的特点等进行了初步探讨.该蛙在大瑶山主要分布在海拔800 m左右的一个狭窄区域,10月至次年1月下山繁殖,有效性比为5:1.蝌蚪唇齿式为Ⅰ∶5-5/1-1:Ⅳ和Ⅰ:4-4/1-1:Ⅳ,越冬后在5~6月完成变态.由于人为和自然因素的影响,该蛙种群受到严重威胁,应加强保护管理和宣传教育.

  15. Extraction and Characterization of Undenatured Type Ⅰ Collagen from the Bullfrog Skin%牛蛙皮中未变性Ⅰ型胶原蛋白的提取及性能表征

    Institute of Scientific and Technical Information of China (English)

    杨波; 李国英

    2012-01-01

    Distribution pattern of collagen in the bullfrog skin was observed in this study. Acid - soluble collagen (ASC) and pepsin - soluble collagen ( PSG) were extracted from the bullfrog skin by acetic acid and acetic acid - pepsin f respectively. Results of the studies on the physicochemical properties of ASC and PSC indicated that the collagen gained was undenatured type I collagen. Ultraviolet absorption spectra showed that the absorption peak of bullfrog collagen was 233 nm. The denaturation temperature of ASC (32.60 ℃.) was higher than that of PSC (32.22 ℃,) , whereas the isoelectric point of ASC(6.79) was lower than that of PSC(7. 15). The imino acid content of collagen from bullfrog skin was lower than that from calf skin and higher than that from fish skin. Moreover, cysteine, which was not existed in calf skin collagen, was observed in bullfrog skin collagen.%观察了胶原蛋白在牛蛙皮肤组织中的分布形态.分别采用酸法和酸酶法提取得到酸溶胶原(ASC)和酶溶胶原(PSC).理化性质分析结果表明:所提取得到的胶原为未变性Ⅰ型胶原;紫外吸收峰在233nm处;ASC的变性温度(32.60℃)高于PSC的变性温度(32.22℃),而ASC的等电点(6.79)低于PSC的等电点(7.15);牛蛙皮胶原的氨基酸组分中,亚氨基酸的含量较牛皮的低,较鱼皮的高,同时,牛蛙皮胶原中含有牛皮胶原中没有的半胱氨酸.

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

    Science.gov (United States)

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

    2010-01-01

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

  17. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

    Science.gov (United States)

    Sparling, D.W.; Fellers, G.

    2007-01-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. ?? 2006 Elsevier Ltd. All rights reserved.

  18. Characteristics of Columbia spotted frog (Rana luteiventris) oviposition sites in northeastern Oregon, USA

    Science.gov (United States)

    Pearl, C.A.; Adams, M.J.; Wente, W.H.

    2007-01-01

    Several western ranid frogs possess a unique strategy of breeding communally over a short temporal window and reusing oviposition sites between years. However, little is published on the characteristics of oviposition sites selected by these explosive breeders. The Columbia spotted frog (Rana luteiventris) is native to northwestern North America and is of conservation concern in the southern portions of its range. As part of a study examining relationships between livestock grazing and R. luteiventris habitat, we assessed characteristics of the species' oviposition sites in 25 fishless ponds in northeastern Oregon. Oviposition sites were generally in shallow water (<25 cm) close to shore and tended to be in the northeastern portion of ponds. Oviposition sites were found more frequently over heavily vegetated substrates and in areas of less substrate slope and shade than random points in littoral zones. We did not quantify temperature differences within ponds, but the patterns we documented are consistent with preferential use of warmer microhabitats for oviposition.

  19. 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.

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

    Science.gov (United States)

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

    2009-10-01

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

  1. Sound and vibration sensitivity of VIIIth nerve fibers in the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    , the animals were stimulated with dorso-ventral vibrations, and the sound-induced vertical vibrations in the setup could be canceled by emitting vibrations in antiphase from the vibration exciter. All low-frequency fibers responded to both sound and vibration with sound thresholds from 23 dB SPL and vibration......We have studied the sound and vibration sensitivity of 164 amphibian papilla fibers in the VIIIth nerve of the grassfrog, Rana temporaria. The VIIIth nerve was exposed using a dorsal approach. The frogs were placed in a natural sitting posture and stimulated by free-field sound. Furthermore...... thresholds from 0.02 cm/s2. The sound and vibration sensitivity was compared for each fiber using the offset between the rate-level curves for sound and vibration stimulation as a measure of relative vibration sensitivity. When measured in this way relative vibration sensitivity decreases with frequency from...

  2. Micronuclei induction in Rana catesbeiana tadpoles by the pyrethroid insecticide lambda-cyhalothrin

    Directory of Open Access Journals (Sweden)

    Campana Marcela Alejandra

    2003-01-01

    Full Text Available Pyrethroid lambda-cyhalothrin genotoxicity was evaluated using the micronucleus test in Rana catesbeiana tadpoles. The effects of concentration and exposure time on the micronuclei frequency were studied in blood smears obtained from tadpoles exposed to four concentrations (0.02, 0.1, 0.2 and 0.4 mg/L of the compound for 24, 48, 72 and 96 h and 8, 15, 20 and 30 days. As a positive control, tadpoles were exposed to cyclophosphamide (5 mg/L. The micronucleated cell frequency was expressed per 1,000 cells. R. catesbeiana tadpoles exposed to increasing concentrations of lambda-cyhalothrin showed an increase in the micronuclei frequency in peripheral blood. Tadpoles exposed to cyclophosphamide (CP also showed a significant increase in micronucleated erythrocytes which peaked after 15 days. These results suggest that R. catesbeiana tadpoles may provide a useful model for monitoring water pollution.

  3. Peptidomics and genomics analysis of novel antimicrobial peptides from the frog, Rana nigrovittata.

    Science.gov (United States)

    Ma, Yufang; Liu, Cunbao; Liu, Xiuhong; Wu, Jing; Yang, Hailong; Wang, Yipeng; Li, Jianxu; Yu, Haining; Lai, Ren

    2010-01-01

    Much attention has been paid on amphibian peptides for their wide-ranging pharmacological properties, clinical potential, and gene-encoded origin. More than 300 antimicrobial peptides (AMPs) from amphibians have been studied. Peptidomics and genomics analysis combined with functional test including microorganism killing, histamine-releasing, and mast cell degranulation was used to investigate antimicrobial peptide diversity. Thirty-four novel AMPs from skin secretions of Rana nigrovittata were identified in current work, and they belong to 9 families, including 6 novel families. Other three families are classified into rugosin, gaegurin, and temporin family of amphibian AMP, respectively. These AMPs share highly conserved preproregions including signal peptides and spacer acidic peptides, while greatly diversified on mature peptides structures. In this work, peptidomics combined with genomics analysis was confirmed to be an effective way to identify amphibian AMPs, especially novel families. Some AMPs reported here will provide leading molecules for designing novel antimicrobial agents.

  4. Pathophysiology in mountain yellow-legged frogs (Rana muscosa during a chytridiomycosis outbreak.

    Directory of Open Access Journals (Sweden)

    Jamie Voyles

    Full Text Available The disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. Chytridiomycosis is caused by a fungal pathogen (Batrachochytrium dendrobatidis that infects amphibian skin. Although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. To gain a better understanding of chytridiomycosis pathophysiology in wild amphibian populations, we collected blood biochemistry measurements during an outbreak in mountain yellow-legged frogs (Rana muscosa in the Sierra Nevada Mountains of California. We found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance. These findings enhance our knowledge of the pathophysiology of this disease and indicate that disease development is consistent across multiple species and in both laboratory and natural conditions. We recommend integrating an understanding of chytridiomycosis pathophysiology with mitigation practices to improve amphibian conservation.

  5. Neuroendocrine diffuse system of the respiratory tract of Rana temporaria: an immunocytochemical study.

    Science.gov (United States)

    Bodegas, M E; Montuenga, L M; Sesma, P

    1995-11-01

    The neuroendocrine cell population of the respiratory system of Rana temporaria has been studied by means of immunocytochemical methods at the light-microscopic level. Isolated or clustered endocrine cells have been found in the epithelium of the buccal cavity, glottis, larynx, and lung. Nine different types of endocrine isolated cell types can be distinguished according to their immunoreactivity to several regulatory peptides [calcitonin, substance P, bombesin, peptide histidine isoleucine (PHI), cholecystokinin (CCK), and endothelin 1] and neuroendocrine markers (7B2, chromogranin, and serotonin). Neuroepithelial bodies are innervated clusters of cells simultaneously immunoreactive for serotonin and 7B2. Nerves and/or neurons have been detected in different regions of the respiratory system using antibodies against protein gene product 9.5, serotonin, calcitonin gene-related peptide (CGRP), substance P, PHI, helodermin, and CCK.

  6. Workplace safety in Bangladesh ready-made garment sector: 3 years after the Rana Plaza collapse.

    Science.gov (United States)

    Barua, Uttama; Ansary, Mehedi Ahmed

    2016-11-18

    Workplace safety is one of the most important issues in industries worldwide, and is endangered by industrial accidents. Different industrial disasters have resulted in several initiatives worldwide to protect human life and reduce material damage, both nationally and internationally. In Bangladesh, the ready-made garment (RMG) industry is one of the most important export-oriented business sectors, which is facing challenges to ensure workplace safety. The Rana Plaza collapse in Bangladesh is the consequence of such non-compliance. The accident resulted in different local and global initiatives to address the challenges. This article reviews progress and achievement of the initiatives to reduce vulnerability in the Bangladesh RMG industry within 3 years after the deadly accident. In the long run, the challenge is to maintain momentum already created for achieving sustainability in the RMG sector in Bangladesh and maintaining compliance even after the end of support from external partners.

  7. Description of a new brown frog from Tsushima Island, Japan (Anura: Ranidae: Rana).

    Science.gov (United States)

    Matsui, Masafumi

    2014-09-01

    Because all available evidence from allozymes, mtDNA sequences, and artificial hybridization suggests presence of high genetic differentiation between populations of East Asian brown frogs currently assigned to Rana dybowskii Günther, 1876, I compared morphological characters between specimens from Tsushima Island of Japan and Maritime territory of Russia. The population from Tsushima is slightly, but significantly different from R. dybowskii from Russia, including the holotype. I therefore consider the Tsushima population to be specifically distinct, and describe it as a new species R. uenoi. The new species also occurs in the Korean Peninsula and adjacent islands, but the distributional relationships with R. dybowskii are unclear, as detailed distribution in northern Korea is lacking.

  8. Breeding phenology in Rana temporaria. Local variation is due to pond temperature and population size.

    Science.gov (United States)

    Loman, Jon

    2016-09-01

    Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year a variation of up to 3 weeks in start of breeding among local populations. Water temperature was measured in the ponds, and breeding tended to be earlier in warmer ponds (surprise!). Breeding was also earlier in ponds with a large breeding congregation. Alternative reasons for these patterns are suggested and discussed. There was a large residual variation. The common frog has a wide range of acceptable wintering sites, and I hypothesize that the particular choice by a local population may explain part of this residual variation.

  9. Effects of exposure to ultraviolet light on the development of Rana pipiens, the northern leopard frog

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.J.; Wofford, H.W. [Union Univ., Jackson, TN (United States)

    1996-10-01

    The increase in ultraviolet light intensity levels due to ozone depletion recently has been linked to the decline in amphibian population. In this experiment, eggs and larvae of Rana pipiens were subjected to differing amounts of ultraviolet radiation to determine the effects of ultraviolet light on the development of amphibian tadpoles. The total length, length of body without tail, and maximum width of each specimen was recorded for a month of the tadpoles` development, including several measurements after the ultraviolet exposures were concluded. It was found that ultraviolet exposure significantly reduced the size of the organisms in comparison with the control group in all three measured areas. Ultraviolet radiation altered the health and appearance of the exposed organisms and was lethal at large amounts. This experiment showed that ultraviolet radiation could cause many problems in developing amphibians. By slowing their development and physically weakening predation, thus contributing to a decline in overall population levels.

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

    Science.gov (United States)

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

    2009-01-01

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

  11. Variations of intestinal calcium absorption in adult frogs (Rana esculenta). Effect of lysine.

    Science.gov (United States)

    el Maraghi-Ater, H; Hourdry, J; Mesnard, J; Dupuis, Y

    1987-01-01

    Intestinal calcium absorption was investigated in an adult frog (Rana esculenta) by injecting a CaCl2 solution containing 45Ca into the lumen. The 45Ca absorption coefficient in the proximal loop was higher than in the distal loop, only when the CaCl2 solution was left for 4 h. This coefficient increased both in the proximal and distal loops when a 4-h treatment was substituted for a 1-h treatment. The coefficient increased in the whole intestine during the first 2 h of treatment (1 h: 21%; 2 h: 55%) and remained stable afterwards in our experimental conditions. The intestinal calcium absorption increase occurred early in the presence of L-lysine (100 mM), since the coefficient already reached its maximum value (52%) after a 1-h treatment.

  12. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii.

    Science.gov (United States)

    Sparling, D W; Fellers, G

    2007-06-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations.

  13. Changes in activity of the organon vasculosum laminae terminalis in the annual cycle in Rana temporaria.

    Science.gov (United States)

    Krawczyk, S; Dziubek, K; Lach, H

    1978-01-01

    In 70 sexually mature male and femal Rana temporaria frogs captured in natural habitat, mean nuclear volumes for the cells of the pars ependymalis and pars parenchymalis of the organon vasculosum laminae terminalis (OVLT) were determined in seven characteristic stages in life. The mean nuclear volume for the cells of the pars ependymalis and pars parenchymalis of the OVLT showed distinct annual fluctuation. Maximum nuclear volume of the cells in both investigated parts of the OVLT were observed during the breeding period (Ist decade of April), and minimum volume of the nuclei of the pars ependymalis at the beginning of hibernation (IIIrd decade of October), and in the pars parenchymalis near the end of active life (Ist decade of September).

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

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt

    as well as on how habitat quality is affected by patch structure. Although fragmentation is generally thought to have negative effects on connectivity, the results suggest that, depending on patch structure and habitat quality, positive effects on connectivity may occur. The second manuscript uses a light...... 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...... must be expected to have implication on both local and regional persistence; the former due to habitat destruction, the latter because of disrupted dispersal between subpopulations due to barrier effects. The result of the project was the development of the model presented in this thesis. The model...

  15. 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.

  16. Cutaneous transport of Ca2+ in the frog Rana pipiens: significance and specificity.

    Science.gov (United States)

    Stiffler, D F; Eskandari, S; Dejbakhsh, S

    1997-04-01

    Rana pipiens were divided into four groups: controls; hypocalcemic frogs, depleted of salts by acclimation to deionized water; hypercalcemic frogs, calcium-loaded by the introduction of 40 mumol calcium gluconate; and frogs exposed to the potential competing ions Mg2+, Sr2+, and Ba2+. All groups displayed calcium influx that was proportional to external [Ca2+]; however, the group acclimated to deionized water also displayed hypocalcemia (P 0.3 mM) external [Ca2+]. Ca2+ efflux was depressed in hypocalcemic frogs, and thus net Ca2+ flux shifted from net loss in control frogs to net uptake in hypocalcemic frogs. Hypocalcemia also resulted in increased skin Ca2+ deposits which may be related to a decreased Ca2+ (and other ions) permeability as a consequence of the acclimation to deionized water. Another group of frogs was Ca(2+)-loaded by injecting calcium gluconate: Sodium gluconate controls did not significantly alter Ca2+ fluxes. The frogs that received calcium gluconate treatments became hypercalcemic (P < 0.01) and did not display significant changes in calcium fluxes, nor did they show significant changes in skin calcium deposits. We conclude that hypocalcemia leads to regulatory responses that stimulate active Ca2+ transport in Rana pipiens skin and possibly inhibits cutaneous and renal efflux. We also conclude that hypercalcemia does not alter calcium fluxes across skin. The ions from Group IIA of the Periodic Table of Elements had little effect on Ca2+ fluxes at concentrations ranging from 0.5-4.0 mM; neither Sr2+ or Ba2+ affected Ca2+ influx. The only divalent ion tested that influenced Ca2+ was Mg2+, which significantly inhibited Ca2+ influx but only at 4.0 mM or eight times the external [Ca2+]. We conclude, therefore, that the Ca2+ transport mechanism is fairly specific for Ca2+ within Group IIA.

  17. 东北林蛙满负荷放养技术%The Rana chensinensis full load cultivation techniques

    Institute of Scientific and Technical Information of China (English)

    宋玉波

    2015-01-01

    本文提出了东北林蛙养殖新模式———满负荷放养,并对该养殖模式的标准化蛙场基础设施建设、计划放养和科学管理等主要技术环节进行了详细介绍,可为林蛙养殖提供借鉴。%The full load cultivation which was the new cultivation mode of Rana chensinensis was raised in this paper.The standardized frog infrastructure construction, cultivation plan and scientific management of this cultivation mode were intro-duced.It provided reference to Rana chensinensis cultivation.

  18. A skeletochronological study of growth, longevity, and age at sexual maturity in a population of Rana latastei (Amphibia, Anura)

    Indian Academy of Sciences (India)

    Fabio M Guarino; Silvia Lunardi; Michela Carlomagno; Stefano Mazzotti

    2003-12-01

    Longevity and age at sexual maturity in an Italian population of Rana latastei were studied by skeletochronology performed on the phalanges. Frogs collected in 1998 and 1999 by drift fences and pitfall traps were marked by toe-clipping. After marking, individuals were released and the cut phalanges were processed for skeletochronological analysis. The maximum age so far recorded was 3 years in males and 4 years in females. The smallest male and female that were sexually mature on the basis of histological analysis of the gonads were 36 and 35 mm snout vent length (SVL), respectively. In both sexes, most individuals were estimated to breed shortly after emergence from their first overwintering. Among the European Brown Frogs, Rana latastei appears to be one of the shortest-lived and one of the first to reach sexual maturity.

  19. 稻田养殖美国青蛙试验%An Experiment on Raising Rana grylio in Rice Fields

    Institute of Scientific and Technical Information of China (English)

    乔志刚; 李学军; 聂国兴

    2000-01-01

    在稻田中放养美国青蛙(Rana grglio),利用稻蛙共生的生态学原理,促进了水稻生长,减少了养蛙占地,每公顷产水稻7 770 kg,商品蛙2 731.5 kg.生态效益、经济效益明显优于未养蛙稻田.

  20. Local adaptation with high gene flow: temperature parameters drive adaptation to altitude in the common frog (Rana temporaria)

    OpenAIRE

    2014-01-01

    Both environmental and genetic influences can result in phenotypic variation. Quantifying the relative contributions of local adaptation and phenotypic plasticity to phenotypes is key to understanding the effect of environmental variation on populations. Identifying the selective pressures that drive divergence is an important, but often lacking, next step. High gene flow between high- and low-altitude common frog (Rana temporaria) breeding sites has previously been demonstrated in Scotland. ...

  1. Infestación por esparganos en ranas del genero Pristimantis (Anura, Strabomantidae del Perú

    Directory of Open Access Journals (Sweden)

    Luis A. Gomez-Puerta

    2011-05-01

    Full Text Available En el presente estudio, reportamos el parasitismo por esparganos del cestode Spirometra sp. en los anfibios: Pristimantis nephophilus y Pristimantis rhodostichus, provenientes del departamento de San Martin, Perú. Tres estructuras filiformes localizadas a nivel subcutáneo, fueron colectadas e identificadas como esparganos. El hallazgo de este metacestode constituye el primer registro en anfibios del Perú y demuestra que las ranas P. nephophilus y P. rhodostichus son nuevos hospederos intermediarios para Spirometra sp.

  2. Bioaccumulation of macro- and trace elements by European frogbit (Hydrocharis morsus-ranae L.) in relation to environmental pollution.

    Science.gov (United States)

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra

    2016-02-01

    The aim of present study was to investigate the level of trace metals and macroelements in Hydrocharis morsus-ranae collected from regions differing in the degree and type of pollution. Concentrations of 17 macro- and microelements were determined in roots and shoots of European frogbit as well as in water and bottom sediments from 30 study sites. Plants differed in concentrations of elements and bioaccumulation capacity depending on the characteristics of dominant anthropogenic activities in the vicinity of the sampling site. Shoots of H. morsus-ranae growing in the vicinity of organic chemistry plants and automotive industry contained particularly high levels of Cd, Co, and S. Plants from area close to heat and power plant, former ferrochrome industry and new highway, were distinguished by the highest concentrations of Cr, Cu, and Pb. European frogbit from both these regions contained more Fe, Hg, Mn, Ni, and Zn than plants from agricultural and recreational areas. The concentrations of alkali metals and Co, Fe, and N in H. morsus-ranae were elevated in relation to the natural content in macrophytes irrespectively to their content in the environment. Based on the values of Bioaccumulation and Translocation Factors, European frogbit is an accumulator for Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn and a good candidate for phytoremediation of water polluted with Co, Cu, Hg, K, Mn, and Ni. The amount of Co and Mn removed from water and accumulated in the plant biomass during the vegetation season was considerably high.

  3. Blood and urine physiological values in farm-cultured Rana catesbeiana (Anura: Ranidae in Argentina

    Directory of Open Access Journals (Sweden)

    José A Coppo

    2005-09-01

    Full Text Available A total of 302 samples of healthy farm-cultured Rana catesbeiana specimens (9-21 months-old, 50- 350 g liveweight, 50% each sex from the north-east of Argentina, were analyzed through spectrophotometry, electrophoresis, densitometry, refractometry and microscopy in order to obtain blood and urine normal values. Confidence intervals (pCon el propósito de obtener valores normales sanguíneos y urinarios, 302 muestras de ejemplares sanos de Rana catesbeiana del nordeste argentino (9-21 meses de edad, 50-350 g de peso vivo, 50% de cada sexo, fueron analizados por espectrofotometría, electroforesis, densitometría, refractometría y microscopía. Fueron obtenidos intervalos de confianza (p<0.05 para hematocrito (28.6-31.6%, eritrocitos (0.40-0.44 T/L, VCM (686-732 fL, hemoglobina (6.41-7.20 g/dL, HCM (151-164 pg, CHCM (22.6-24.0%, leucocitos (18.7-22.3 G/L, neutrófilos (58.4-63.4%, linfocitos (23.9-29.8%, monocitos (2.1-3.8%, eosinófilos (4.6-7.0%, basófilos (2.9-4.1%, tiempo de sangría (289-393s, tiempo de coagulación (452- 696s, tiempo de protrombina (76-128s, densidad urinaria (1.0061-1.0089 g/mL, pH urinario (6.38-6.96, fibrinógeno (0.59-0.99 g/dL, proteínas totales (4.19-4.49 g/dL, albúmina (1.49-1.67 g/dL, alfa-1 globulina (0.20-0.24 g/dL, alfa-2 globulina (0.48-0.54 g/dL, beta globulina (0.68-0.77 g/dL, gamma globulina (1.28-1.42 g/dL, relación albúmina/globulinas (0.50-0.58, creatinina (4.09-5.56 mg/L, urea (76.1-92.4 mg/L, ácido úrico (11.5-15.4 mg/L, triglicéridos (0.34-0.52 g/L, colesterol total (0.56-0.67 g/L, C-HDL (0.03-0.05 g/L, C-LDL (0.34-0.44 g/L, alfa lipoproteína (6.01-8.67%, beta lipoproteína (91.3-93.9%, glucosa (0.45-0.54 g/L, Na (116-121 meq/L, K (3.42- 3.81 meq/L, Cl (100-116 meq/L, Ca (7.98-8.61 mg/dL, P (8.31-9.36 mg/dL, Mg (2.26-2.55 mg/dL, Fe (105-178 ug/dL, ALP (144-170 IU/L, ALT (10.0-14.8 IU/L, AST (42.8-53.4 IU/L, GGT (7.8-10.6 IU/L, LDH (99-135 IU/L, CHE (151-185 IU/L y CPK (365-500 IU/L. Algunos

  4. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    Science.gov (United States)

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models.

  5. Widespread occurrence of the chytrid fungus batrachochytrium dendrobatidis on oregon spotted frogs (rana pretiosa)

    Science.gov (United States)

    Pearl, C.A.; Bowerman, J.; Adams, M.J.; Chelgren, N.D.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines in multiple continents, including western North America. We investigated Bd prevalence in Oregon spotted frog (Rana pretiosa), a species that has declined across its range in the Pacific Northwest. Polymerase chain reaction analysis of skin swabs indicated that Bd was prevalent within populations (420 of 617 juvenile and adults) and widespread among populations (36 of 36 sites) where we sampled R. pretiosa in Oregon and Washington. We rarely detected Bd in R. pretiosa larvae (2 of 72). Prevalence of Bd in postmetamorphic R. pretiosa was inversely related to frog size. We found support for an interactive effect of elevation and sampling date on Bd: prevalence of Bd generally increased with date, but this effect was more pronounced at lower elevations. We also found evidence that the body condition of juvenile R. pretiosa with Bd decreased after their first winter. Our data indicate that some Oregon spotted frog populations are currently persisting with relatively high Bd prevalence, but the risk posed by Bd is unknown. ?? 2010 International Association for Ecology and Health.

  6. California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

    Science.gov (United States)

    Fellers, G.M.; Kleeman, P.M.

    2007-01-01

    Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  7. Population structure of Columbia spotted frogs (Rana luteiventris) is strongly affected by the landscape

    Science.gov (United States)

    Funk, W.C.; Blouin, M.S.; Corn, P.S.; Maxell, B.A.; Pilliod, D.S.; Amish, S.; Allendorf, F.W.

    2005-01-01

    Landscape features such as mountains, rivers, and ecological gradients may strongly affect patterns of dispersal and gene flow among populations and thereby shape population dynamics and evolutionary trajectories. The landscape may have a particularly strong effect on patterns of dispersal and gene flow in amphibians because amphibians are thought to have poor dispersal abilities. We examined genetic variation at six microsatellite loci in Columbia spotted frogs (Rana luteiventris) from 28 breeding ponds in western Montana and Idaho, USA, in order to investigate the effects of landscape structure on patterns of gene flow. We were particularly interested in addressing three questions: (i) do ridges act as barriers to gene flow? (ii) is gene flow restricted between low and high elevation ponds? (iii) does a pond equal a 'randomly mating population' (a deme)? We found that mountain ridges and elevational differences were associated with increased genetic differentiation among sites, suggesting that gene flow is restricted by ridges and elevation in this species. We also found that populations of Columbia spotted frogs generally include more than a single pond except for very isolated ponds. There was also evidence for surprisingly high levels of gene flow among low elevation sites separated by large distances. Moreover, genetic variation within populations was strongly negatively correlated with elevation, suggesting effective population sizes are much smaller at high elevation than at low elevation. Our results show that landscape features have a profound effect on patterns of genetic variation in Columbia spotted frogs.

  8. Multiple sublethal chemicals negatively affect tadpoles of the green frog, Rana clamitans

    Science.gov (United States)

    Boone, Michelle D.; Bridges, Christine M.; Fairchild, James F.; Little, Edward E.

    2005-01-01

    Many habitats may be exposed to multiple chemical contaminants, particularly in agricultural areas where fertilizer and pesticide use are common; however, the singular and interactive effects of contaminants are not well understood. The objective of our study was to examine how realistic, sublethal environmental levels of ammonium nitrate fertilizer (0, 10, 20 mg/L and ammonium chloride control) and the common insecticide carbaryl (0 or 2.5 mg/L) individually and interactively affect the development, size, and survival of green frog (Rana clamitans) tadpoles. We reared tadpoles for 95 d in outdoor 1,000-L polyethylene ponds. We found that the combination of carbaryl and nitrate had a negative effect on development and mass of tadpoles compared to the positive effect that either contaminant had alone. Presence of carbaryl was generally associated with short-term increases in algal resources, including ponds exposed to both carbaryl and nitrate. However, with exposure to nitrate and carbaryl, tadpole mass and development were not positively affected as with one chemical stressor alone. The combination of these sublethal contaminants may reduce the ability of amphibians to benefit from food-rich environments or have metabolic costs. Our study demonstrates the importance of considering multiple stressors when evaluating population-level responses.

  9. Mercury pollution in Rana Chensinensis in Weisha River reach, in the upstream region of Songhua River

    Institute of Scientific and Technical Information of China (English)

    WANG Ning; ZHU Yanming; SHENG Lianxi; MENG Dan

    2005-01-01

    Twice a year continuous samples of Rana Chensinensis and sediments have been collected near gold mine in the upstream region of Songhua River from 2000 to 2002, for analyzing the total mercury (THg), methylmercury (MeHg) concentration and correlation in sediments, muscles, livers of the frog. The study indicates that THg and MeHg concentrations in polluted samples near the gold mine are higher than those in unpolluted ones. THg and MeHg concentrations are higher in autumn, in female, and in livers than those in spring, in male, in muscles respectively. The order of concentration degree in the frog organizations is as follows: liver>muscle>ovum>Fallopian tube. MeHg is the main form of mercury (Hg) existing in autumn, while inorganic Hg is in spring. There is no distinct difference of CMeHg/CTHg between male and female, livers and muscles. The correlation between MeHg concentrations in the river sediments and in the frog's livers and muscles are significant, which is related to disorderly discharge of Hg.

  10. Clinal patterns in genetic variation for northern leopard frog (Rana pipiens): Conservation status and population histories

    Science.gov (United States)

    Stockwell, Craig A.; Fisher, Justin D.L.; McLean, Kyle I.

    2016-01-01

    The security of the northern leopard frog (Rana pipiens) varies spatially with populations east and west of North Dakota considered as secure and at risk, respectively. We used genetic markers to characterize the conservation status of northern leopard frog populations across North Dakota. We used multiple regression analyses and model selection to evaluate correlations of expected heterozygosity (HE) with the direct and additive effects of: i) geographic location,ii) wetland density and iii) average annual precipitation. There was lower genetic diversity in the western portion of the state due to lower levels of diversity for populations southwest of the Missouri River. This may reflect a refugial/colonization signature for the only non-glaciated area of North Dakota. Genetic diversity was also positively associated with wetland densities which is consistent with the reliance of this species on a mosaic of wetlands. Our findings suggest that populations in the southwestern part of North Dakota are of higher conservation concern, a finding consistent with the higher risk noted for northern leopard frog populations in most states west of North Dakota. Our findings also pose the hypothesis that climate change induced changes in wetland densities will reduce genetic diversity of northern leopard frog populations.

  11. Cytonuclear discordance and historical demography of two brown frogs, Rana tagoi and R. sakuraii (Amphibia: Ranidae).

    Science.gov (United States)

    Eto, Koshiro; Matsui, Masafumi

    2014-10-01

    Prior studies of mitochondrial genomic variation reveal that the Japanese brown frog Rana tagoi comprises a complex of cryptic species lineages, and that R. sakuraii arose from within this complex. Neither species forms a monophyletic group on the mitochondrial haplotype tree, precluding a simple explanation for the evolutionary origins of R. sakuraii. We present a more complete sampling of mitochondrial haplotypic variation (from the ND1 and 16S genes) plus DNA sequence variation for five nuclear loci (from the genes encoding NCX1, NFIA, POMC, SLC8A3, and TYR) to resolve the evolutionary histories of these species. We test hypotheses of population assignment (STRUCTURE) and isolation-with-migration (IM) using the more slowly evolving nuclear markers. These demographic analyses of nuclear genetic variation confirm species-level distinctness and integrity of R. sakuraii despite its apparent polyphyly on the mitochondrial haplotype tree. Divergence-time estimates from both the mitochondrial haplotypes and nuclear genomic markers suggest that R. sakuraii originated approximately one million years ago, and that incomplete sorting of mitochondrial haplotype lineages best explains non-monophyly of R. sakuraii mitochondrial haplotypes. Cytonuclear discordance elsewhere in R. tagoi reveals a case of mitochondrial introgression between two species lineages on Honshu. The earliest phylogenetic divergence within this species group occurred approximately four million years ago, followed by cladogenetic events in the Pliocene and early Pleistocene yielding 10-13 extant species lineages, including R. sakuraii as one of the youngest.

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

    Science.gov (United States)

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

    2013-01-01

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

  13. 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.

  14. Effects of prochloraz and ethinylestradiol on sexual development in Rana temporaria.

    Science.gov (United States)

    Brande-Lavridsen, Nanna; Christensen-Dalsgaard, Jakob; Korsgaard, Bodil

    2008-08-01

    A wide range of environmental xenobiotics that mimic hormones (endocrine-disrupting chemicals) may cause alterations in sexual development or reproductive function in aquatic organisms such as amphibians when exposed during early sensitive stages. We exposed tadpoles of the Common frog, Rana temporaria, from hatch to metamorphosis, to two different endocrine disruptors, the synthetic estrogen 17 alpha-ethinylestradiol and the fungicide prochloraz. The object of the study was to assess the effects of these two compounds on the sexual development of the tadpoles by investigating sex ratio, gonadal development, sex steroid concentrations and vitellogenin induction. Histology revealed that a large percentage of all groups were juvenile hermaphrodites at metamorphosis. Tadpoles exposed to 115 and 251 microg/L prochloraz showed a significant increased proportion of males. However, the testosterone concentrations were depressed in those groups. Ethinylestradiol in concentrations of 77 and 159 ng/L EE(2) increased whole-body calcium levels in a dose-dependent manner indicating induction of the egg yolk protein vitellogenin, verified also by gel electrophoresis. The study shows that ethinylestradiol may induce vitellogenesis and prochloraz may affect the sexual development in Common frogs.

  15. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria.

    Science.gov (United States)

    Matsuba, Chikako; Miura, Ikuo; Merilä, Juha

    2008-01-08

    Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals - for which there is earlier evidence from this species - are frequently occurring.

  16. Polychlorinated biphenyls, sex steroid hormones and liver retinoids in adult male European common frogs Rana temporaria.

    Science.gov (United States)

    Mikkelsen, Mattis; Jenssen, Bjørn Munro

    2006-05-01

    Declines in amphibian populations and species biodiversity during the last decades has called for an assessment of possible threats to these animals. Polychlorinated biphenyls (PCBs) are known endocrine disrupting contaminants and are found in high levels in some populations of wild living amphibians. To evaluate the endocrine disrupting potential of PCBs in adult frogs, Aroclor 1,254 were subcutaneously injected into male European common frogs Rana temporaria. The injected doses ranged from 0.01 to 100 mg/kg body mass, resulting in liver concentrations between 74 and 133,619 microg/kg ww. After 14 days, serum testosterone (T), estradiol (E) and hepatic retinol (R) and retinylpalmitate (RP) were easured. No dose dependent effects were found on levels of hormones or retinoids. However, a significantly higher within-group variation in the E-T ratio in the exposed groups may indicate that the sex-hormone homeostasis of male R. temporaria is affected by PCBs shortly after arousal from hibernation, but that the effects are subtle and that several different mechanisms are involved. The lack of direct effect on T, E, R and RP may be due to the timing of exposure (shortly after arousal from hibernation), or due to a relatively short exposure time to Aroclor 1,254. Based on the results, we propose that future research should focus on effects of PCBs in relation to the different physiological phases frogs experience throughout the year (hibernation, reproduction etc.).

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

    Directory of Open Access Journals (Sweden)

    M. BURA

    2013-12-01

    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.

  18. genotoxicity of the pesticide dichlorvos and herbicide butachlor on rana zhenhaiensis tadpoles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    genotoxicity of dichlorvos and butachlor on erythrocytes of rana zhenhaiensis tadpoles was investigated by the alkaline single-cell gel electrophoresis assay or comet assay.tadpoles were treated for 24 h in the laboratory with different concentrations of the testing agents,2.256,4.512,6.768,9.024,11.280 mg/l for dichlorvos and 0.292,0.584,0.876,1.168,1.460 mg/l for butachlor,to use the comet assay to test for the significance of dosage responsiveness to an increase in dna damage,as measured by the mean dna tail length-to-width ratio.the concentrations of 4.512 mg/l dichlorvos and 0.876 mg/l butachlor resulted in highly significant increases in dna damage of the tadpoles.there were linear correlations between the mean dna tail length-to-width ratio and the concentrations of the two test substances.our results showed that the two commonly used agricultural chemicals caused dose dependent dna damage of amphibians,and that comet assay might be a useful tool for measuring dna damage of tadpoles exposed in the field.

  19. Neuronal intermediate filaments in the developing tongue of the frog Rana esculenta

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    K Zuwala

    2009-06-01

    Full Text Available The expression of several neuronal intermediate filament (NIF proteins was investigated in the tongue of metamorphosing tadpoles (stage 38-45 of Gosner and in adult individuals of the frog, Rana esculenta by means of immunohistochemistry. Results showed that nerve fibres at early stages of tongue development expressed peripherin (a NIF protein usually found in differentiating neurones as well as the light- and medium molecular weight NIF polypeptide subunits (NF-L and NF-M, respectively; in the adult frog, peripherin was still found in nerve fibres reaching the fungiform papilla together with NF-M, but NF-L immunoreactivity was absent therein. Clusters of epithelial cells expressing peripherin were found in the early developing tongue before differentiation of taste organs, and NF-L and NF-H immunoreactivities were present in basal (Merkel cells of the adult frog taste disc. Results indicate that neurones innervating the adult frog’s taste disc maintain a certain plasticity in their cytoskeleton and that neuronal-like cells are present in the undifferentiated and differentiated tongue epithelium possibly playing a role in the developing and mature taste organ.

  20. Effects of agricultural pesticides on the immune system of Xenopus laevis and Rana pipiens

    Energy Technology Data Exchange (ETDEWEB)

    Christin, M.S.; Menard, L.; Gendron, A.D.; Ruby, S.; Cyr, D.; Marcogliese, D.J.; Rollins-Smith, L.; Fournier, M

    2004-03-30

    Over the last 30 years, there have been mass declines in diverse geographic locations among amphibian populations. Multiple causes have been suggested to explain this decline. Among these, environmental pollution is gaining attention. Indeed, some chemicals of environmental concern are known to alter the immune system. Given that amphibians are frequently exposed to agricultural pesticides, it is possible that these pollutants alter their immune system and render them more susceptible to different pathogens. In this study, we exposed two frog species, Xenopus laevis and Rana pipiens, for a short period of time to a mixture of pesticides (atrazine, metribuzine, endosulfan, lindane, aldicarb and dieldrin) representative in terms of composition and concentrations to what it is found in the environment of the southwest region of the province of Quebec. The pesticides were known to be present in surface water of many tributaries of the St. Lawrence River (Quebec, Canada). Our results demonstrate that the mixture of pesticides could alter the cellularity and phagocytic activity of X. laevis and the lymphocyte proliferation of R. pipiens. Taken together, these results indicate that agricultural pesticides can alter some aspects of the immune response in frogs and could contribute to their global decline by rendering them more susceptible to certain infections.

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

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    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.

  2. Molecular cloning and expression patterns of the Vasa gene from Rana nigromaculata (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Rui Jia

    2009-06-01

    Full Text Available The Vasa protein is a member of the DEAD (Asp-Glu-Alu-Asp box family of ATP-dependent RNA helicases. The Vasa gene is specifically expressed in germ-line cells of many metazoans and is known to play a critical role in gametogenesis and reproductive regulation. In this paper, we isolate the full length cDNA sequence of the Vasa gene from the frog Rana nigromaculata Hallowell, 1861. The open reading frame (ORF encoding 398 amino acid residues has nine conserved motifs. According to the similarities at the amino acid sequenceythe phylogenetic analysis of Vasa gene was consistent with the evolution relationships from chordates to mammals. Furthermore, the expression pattern analysis of RnVasa mRNA, using the technique of Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR, showed a high level of transcripts in testis, ovary and kidney, whereas little to no signal was detected in other tissues, which suggests that it may play a role during gametogenesis.

  3. Antimicrobial peptides with atypical structural features from the skin of the Japanese brown frog Rana japonica.

    Science.gov (United States)

    Isaacson, Todd; Soto, AnaMaria; Iwamuro, Shawichi; Knoop, Floyd C; Conlon, J Michael

    2002-03-01

    Japonicin-1 (FFPIGVFCKIFKTC) and japonicin-2 (FGLPMLSILPKALCILLKRKC), two peptides with differential growth-inhibitory activity against the Gram-negative bacterium, Escherichia coli and the Gram-positive bacterium Staphylococcus aureus, were isolated from an extract of the skin of the Japanese brown frog Rana japonica. Both peptides show little amino acid sequence similarity to previously characterized antimicrobial peptides isolated from the skins of Ranid frogs. Circular dichroism studies, however, demonstrate that japonicin-2 adopts an alpha-helical conformation in 50% trifluoroethanol in common with many other cationic antimicrobial peptides synthesized in amphibian skin. Peptides belonging to the brevinin-1, brevinin-2, and tigerinin families, previously identified in the skins of Asian Ranid frogs, were not detected but a temporin-related peptide (ILPLVGNLLNDLL.NH(2); temporin-1Ja), that atypically bears no net positive charge, was isolated from the extract. The minimum inhibitory concentrations (MICs) of the peptides against E. coli were japonicin-1, 30 microM; japonicin-2, 12 microM; and temporin-1Ja > 100 microM. The MICs against S. aureus were japonicin-1, > 100 microM; japonicin-2, 20 microM; and temporin-1Ja, > 100 microM.

  4. Neuronal nitric oxide synthase immunoreactivity in the respiratory tract of the frog, Rana temporaria.

    Science.gov (United States)

    Bodegas, M E; Villaro, A C; Montuenga, L M; Moncada, S; Riveros-Moreno, V; Sesma, P

    1995-10-01

    Physiological and histochemical studies have recently supported the notion that nitric oxide (NO) is the transduction signal responsible for the non-adrenergic, non-cholinergic relaxation of the vasculature as well as the airways of the mammalian lung. We report the presence of immunoreactivity to NO synthase (NOS) in nerve cell bodies and nerve fibres in the neural plexus of the buccal cavity and lungs of the frog, Rana temporaria, using the indirect immunocytochemical technique of avidin-biotin and the NADPH-diaphorase technique. The neural ganglia located next to the muscle layer and within the connective tissue of the buccal cavity were partially immunoreactive for NOS. In the lungs, NOS immunoreactivity occurred in nerve cell bodies, as well as in both myelinated and unmyelinated nerve fibres. Fine nerve fibres immunoreactive to NOS were observed within the muscle fibre bundles and next to the respiratory epithelium. Both the presence of NOS immunoreactivity and the positive histochemical reaction for NADPH-diaphorase in the neural plexus of amphibian respiratory tract suggests a broad evolutionary role for NO as a peripheral neurotransmitter.

  5. Metamorphic changes in the stomach of the frog Rana temporaria tadpoles.

    Science.gov (United States)

    Rovira, J; Villaro, A C; Bodegas, M E; Valverde, E; Sesma, P

    1995-02-01

    The histological transformation of amphibian stomach during metamorphosis was studied in the frog Rana temporaria. The earliest metamorphic changes occur shortly before regression of the cloacal piece of tail and appearance of forelegs. Autolysis of primary, larval epithelial cells and activity of phagocytes lead to regression of the apical mucosa, which is shed into the gastric lumen. Histogenesis takes place from the very beginning of metamorphosis in the basal region of the mucosa; undifferentiated, regenerative cells, arranged in small compact cords and surrounded by a thick basement membrane, give rise to secondary lining epithelium and glands. Lining epithelial cells differentiate into a typical mucosecretory epithelium. Oxyntic cells present in larval glands are substituted by both ion- and protein-secreting oxyntic-peptic cells. During metamorphosis, connective and muscular tissues markedly increase, a submucosa, not present in larval tadpoles, gradually develops. A muscularis mucosae is also formed and the muscular propria becomes thicker. At late metamorphosis, folded structures involving both mucosa and submucosa develop, increasing the luminal surface as in adults. Removal of the larval gastric mucosa and its replacement by a new, adult-type definitive one, together with development of peripheral connective and muscular tissues, account for metamorphosis of tadpole stomach.

  6. Mobile phone mast effects on common frog (Rana temporaria) tadpoles: the city turned into a laboratory.

    Science.gov (United States)

    Balmori, Alfonso

    2010-06-01

    An experiment has been made exposing eggs and tadpoles of the common frog (Rana temporaria) to electromagnetic radiation from several mobile (cell) phone antennae located at a distance of 140 meters. The experiment lasted two months, from the egg phase until an advanced phase of tadpole prior to metamorphosis. Measurements of electric field intensity (radiofrequencies and microwaves) in V/m obtained with three different devices were 1.8 to 3.5 V/m. In the exposed group (n = 70), low coordination of movements, an asynchronous growth, resulting in both big and small tadpoles, and a high mortality (90%) was observed. Regarding the control group (n = 70) under the same conditions but inside a Faraday cage, the coordination of movements was normal, the development was synchronous, and a mortality of 4.2% was obtained. These results indicate that radiation emitted by phone masts in a real situation may affect the development and may cause an increase in mortality of exposed tadpoles. This research may have huge implications for the natural world, which is now exposed to high microwave radiation levels from a multitude of phone masts.

  7. Effects of fluoride on development and growth of Rana chensinensis embryos and larvae.

    Science.gov (United States)

    Chai, Lihong; Dong, Suiming; Zhao, Hongfeng; Deng, Hongzhang; Wang, Hongyuan

    2016-04-01

    The present study examined the adverse effects of fluoride exposure on embryos and larvae of Rana chensinensis. Survival, morphological abnormalities, growth and development, time to metamorphosis and size at metamorphic climax of R. chensinensis were examined. Our results showed that embryos malformation occurred in all fluoride treatments. Morphological abnormalities of embryos are characterized by axial flexures, the extrusion of fin axis, edema, and ruffled dorsal and ventral fin. Additionally, 4.1mg F(-)/L and above could significantly inhibit embryos growth and development. On day 15, total length and weight of tadpole were significantly lower in 19.6 and 42.4 mg F(-)/L treatments compared to control. However, significant reductions in total length and weight were observed only at 42.4 mg F(-)/L on day 30. Moreover, significant metamorphic delay and decrease in the size at metamorphic climax were found in larvae exposed to 42.4 mg F(-)/L. Taken together, embryos of R. chensinensis are more vulnerable to fluoride exposure than their tadpoles. Our results suggested that the presence of high concentrations fluoride might increase mortality risk and a reduction in juvenile recruitment in the field by increasing embryos malformation, delaying metamorphosis and decreasing size at metamorphosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  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. Environmental influence on testicular MAP kinase (ERK1) activity in the frog Rana esculenta.

    Science.gov (United States)

    Chieffi, Paolo; Minucci, Sergio

    2004-06-01

    Recent studies suggest a role for ERK1 in the regulation of spermatogonial proliferation. In this report the frog Rana esculenta, a seasonal breeder, was used as a model to study the possible effect on ERK1 of photoperiod and temperature. Adult male R. esculenta were subjected to several combinations of light and temperature at different times of the year to elucidate the regulation of ERK1 testicular activity in the spermatogonial proliferation by these environmental factors. Western blot analysis shows that under controlled experimental conditions an increase of temperature and photoperiod in November, characterized by a decrease in primary spermatogonial mitosis, induces ERK1 activity and spermatogonial proliferation, as confirmed using the proliferating cellular nuclear antigen (PCNA) as an early molecular marker. In contrast, a decrease in temperature and photoperiod in March, with an increase of primary spermatogonial mitosis, impairs ERK1 activity and spermatogonial proliferation. In conclusion, our data clearly show for the first time in a non-mammalian vertebrate that the temperature and the photoperiod exert a role in the spermatogonial proliferation via ERK1 activity.

  10. [Reabsorption of yellow fluorescent protein in the Rana temporaria kidney by receptor-mediated endocytosis].

    Science.gov (United States)

    Seliverstova, E V; Prutskova, N P

    2014-01-01

    The absorption of yellow fluorescent protein (YFP) and the expression of the endocytic receptors, megalin and cubilin, were investigated in the renal proximal tubules (PT) in frogs Rana temporaria after parenteral YFP injections. The methods of confocal microscopy and immunohistochemistry were used. The dynamics of YFP absorption was analyzed 2 h after injection. The logarithmic time dependence of the accumulation of YFP-containing endocytic vesicles in PT cells and the completion of absorption process 90-120 min after injection were shown. Unlike substantial megalin and cubilin expression 15-30 min after YFP introduction, immunolabeled endocytic receptors were not detected in PT cells after 2 h. The re-injection of YFP led to the appearance of apical endocytic vesicles containing megalin or cubilin colocalized with YFP. At the same time, the decrease of YFP uptake associated with reduction in the number of receptor-containing vesicles was demonstrated, suggesting a failure of megalin and cubilin expression. The decrease of absorption capacity of PT cells after YFP re-injection was similar to that found previously under conditions of the competitive absorption of green fluorescent protein (GFP) and YFP injected in different sequences. The data are the further demonstration of the proposed mechanism limiting the tubular protein absorption in the frog kidney and suggest the involvement of megalin and cubilin in uptake and vesicular transport of YFP.

  11. [Reinnervation of a mixed muscle in the frog Rana temporaria with a regenerating homogeneous nerve].

    Science.gov (United States)

    Radziukevich, T L

    1995-01-01

    Mixed muscle m. iliofibularis from the frog Rana temporaria, consisting of monosynaptically innervated phasic and polysynaptically innervated postural muscle fibers, was reinnervated by homogeneous tailor's nerve having no axons of tonic motor system in its composition. Within 2-7 months after nerves binding treatment phasic muscle fibers were easily identified by subneural apparatus structure revealed at coloration of synaptic acetylcholinesterase. Presynaptic part of neuromuscular apparatus of these fibers after the impregnation by protargol was presented by immature nervous terminals. The identification of tonic Muscular fibers was difficult especially at the late stages of reinnervation as subneural apparatus structure typical for tonic fibers was not revealed. Nonmyelinizated nerve fibers without features of terminal branch were observed in individual regions of nonidentified muscle fibers. The results obtained show that subneural apparatus of tonic muscle fibers depends to a great extent on the influence of inherent tonic motor system. Axons of phasic motor system even at distant reinnervation periods and in the absence of competitive influences of tonic motor system do not form typical "phasic" terminal picture of innervation under the contact with tonic muscle fibers.

  12. A Threshold Dosage of Testosterone for Female-to-Male Sex Reversal in Rana rugosa Frogs.

    Science.gov (United States)

    Oike, Akira; Kodama, Maho; Nakamura, Yoriko; Nakamura, Masahisa

    2016-10-01

    Androgens play a critical role in testicular differentiation in many species of vertebrates. While female-to-male sex reversal can be induced by testosterone (T) in some species of amphibians, the mechanism still remains largely unknown even at the histological level. In this study, we determined a threshold dosage of T to induce female-to-male sex reversal in the Japanese frog Rana (R.) rugosa. Tadpoles were allowed to metamorphose into frogs with T present in the rearing water. At 0.2 ng/mL T, female frogs formed tissue comprising a mixture of ovary and testis, the so-called ovotestis, the size of which was significantly smaller than the wild-type ovary. Histological changes occurring in the oocytes of T-treated ovaries induced oocyte degeneration in the masculinizing ovaries leading to their final disappearance. In parallel, many germ cells emerged in the cortex of the ovotestis and, later, in the medulla as well. RT-PCR analysis revealed upregulated expression of CYP17 and Dmrt1 but not 17βHSD in the ovotestis, and downregulation of Pat1a expression. Furthermore, immunohistology revealed CYP17-positive signals in the cortex of the masculinizing ovary, spreading throughout the whole area as the testis developed. These results indicate that oocytes are sensitive to T in the ovary of R. rugosa and that male-type germ cells expand in the masculinizing gonad (testis) contemporaneous with oocyte disappearance. © 2016 Wiley Periodicals, Inc.

  13. Proximate causes of adaptive growth rates: growth efficiency variation among latitudinal populations of Rana temporaria.

    Science.gov (United States)

    Lindgren, B; Laurila, A

    2005-07-01

    In ectothermic organisms, declining season length and lower temperature towards higher latitudes often select for latitudinal variation in growth and development. However, the energetic mechanisms underlying this adaptive variation are largely unknown. We investigated growth, food intake and growth efficiency of Rana temporaria tadpoles from eight populations along a 1500 km latitudinal gradient across Sweden. To gain an insight into the mechanisms of adaptation at organ level, we also examined variation in tadpole gut length. The tadpoles were raised at two temperatures (16 and 20 degrees C) in a laboratory common garden experiment. We found increased growth rate towards higher latitudes, regardless of temperature treatment. This increase in growth was not because of a higher food intake rate, but populations from higher latitudes had higher growth efficiency, i.e. they were more efficient at converting ingested food into body mass. Low temperature reduced growth efficiency most strongly in southern populations. Relative gut length increased with latitude, and tadpoles at low temperature tended to have longer guts. However, variation in gut length was not the sole adaptive explanation for increased growth efficiency as latitude and body length still explained significant amounts of variation in growth efficiency. Hence, additional energetic adaptations are probably involved in growth efficiency variation along the latitudinal gradient.

  14. Toxic effects of NH4(+)-N on embryonic development of Bufo gargarizans and Rana chensinensis.

    Science.gov (United States)

    Deng, Hongzhang; Chai, Lihong; Luo, Pingping; Zhou, Meimei; Nover, Daniel; Zhao, Xiaohong

    2017-09-01

    Although nitrogen fertilizer is commonly used worldwide, little information is currently available about NH4(+)-N toxicity on amphibians. This study determined the acute and chronic toxic effects of NH4(+)-N on two native Chinese amphibian species (Bufo gargarizans and Rana chensinensis), and compared the negative sensitivity of different embryos to NH4(+)-N. Static renewal aqueous exposures were performed using B. gargarizans and R. chensinensis embryos at Gosner stage 2 over 96 h. In terms of 96 h-LC50, B. gargarizans and R. chensinensis embryos had significantly different responses to NH4(+)-N, and the latter was more sensitive to NH4(+)-N than the former. In the chronic toxicity test, exposure to 10 mg L(-1)NH4(+)-N or higher significantly decreased the hatching rate of embryos in both species. Significant increases in the abnormality rate of embryos at 50 mg L(-1)NH4(+)-N or higher were observed and morphological abnormalities were characterized by axial flexures, yolk sac edema, and hyperplasia in both species. Additionally, the total length of embryos decreased in a dose-dependent manner after exposure to NH4(+)-N. The results indicate that NH4(+)-N exposure can increase abnormality and inhibit the hatching and development of embryos in B. gargarizans and R. chensinensis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

    Energy Technology Data Exchange (ETDEWEB)

    Sparling, D.W. [Cooperative Wildlife Research Laboratory, Department of Zoology and Center for Ecology, Southern Illinois University, LS II, MS6504, Carbondale, IL 62901 (United States)]. E-mail: dsparl@siu.edu; Fellers, G. [Western Ecology Research Center, U.S. Geological Survey, Point Reyes National Seashore, Point Reyes, CA 94956 (United States)

    2007-06-15

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. - Laboratory tests on the toxicity of OP insecticides and their oxons suggest that they may be acutely lethal to amphibians at ecologically relevant concentrations.

  16. Prehibernation Energy Storage in Heilongjiang Brown Frogs (Rana amurensis) from Five Populations in North China

    Institute of Scientific and Technical Information of China (English)

    Wei CHEN; Tianpei GUAN; Lina REN; Dujuan HE; Ying WANG; Xin LU

    2015-01-01

    Energy storage is an important component in the life history of species that directly inlfuences survival and reproduction. The energetic demands of amphibian reproduction can differ between the sexes, with environmental conditions, reproductive pattern or process of the species, and depending upon the timing of breeding, and the reproductive season for a species. Surprisingly, comparative studies of pre-hibernation energy storage for anuran populations from different latitudes are relatively few in Asia, especially in China. Here we investigated the patterns of pre-hibernation energy storage of Heilongjiang brown frogsRana amurensis, based on ifve populations along a ifnely latitudinal gradient in north China (40.7–43.7°N). We found that pre-hibernation energy storage of the frogs did not show a clear latitudinal cline, but differed strongly between the sexes, with males depositing more energy reserves into the muscle and liver, whereas females accumulate more energy in the gonads. The sexual differences in energy storage may result from differential timing of energy allocation for reproduction.

  17. Hematological, Biochemical and Histopathological Studies on Marsh Frog, Rana ridibunda, Naturally Infected with Waltonella duboisi

    Directory of Open Access Journals (Sweden)

    A.M. Al-Attar

    2010-01-01

    Full Text Available The present study was aimed to evaluate the impact of Waltonella duboisi naturally infection in the marsh frog, Rana ridibunda. Healthy and infected frogs of both sexes were collected from Al-Qatif and Al-Hassa farms, Eastern Province, Saudi Arabia. The hematological, biochemical and histopathological changes were estimated in infected male and female frogs compared with healthy frogs. The values of red blood cell count, hemoglobin concentration, hematocrit, mean cell volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and white blood cell count were statistically decreased in infected frogs. Infection with Waltonella duboisi induced significant reduction in the levels of serum glucose and total proteins, while the values of triglycerides cholesterol, creatinine, glutamic pyruvic acid transaminase and glutamic oxaloacetic acid transaminase were significantly elevated. Histopathological examination of stomach, small intestine, liver showed the larval developmental stages of Waltonella duboisi. A partially abnormal of testis and ovary structures with pronounced disturbance in quantity and quality of spermatogenesis and oogenesis processes were noted in infected of both sexes of frogs. From the present study, it is obviously that Waltonella duboisi caused many severe physiological and histopathological alterations in both sexes of the marsh frogs. Thus, more sincere ecological and scientific efforts are required to rescue the marsh frog population from parasitic infection, pathogenic factors and increases of mortality rate.

  18. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

    Directory of Open Access Journals (Sweden)

    Merilä Juha

    2008-01-01

    Full Text Available Abstract Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. Results A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. Conclusion These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals – for which there is earlier evidence from this species – are frequently occurring.

  19. Characterization and antioxidant activity in vitro and in vivo of polysaccharide purified from Rana chensinensis skin.

    Science.gov (United States)

    Wang, Zhanyong; Zhao, Yuanyuan; Su, Tingting; Zhang, Jing; Wang, Fei

    2015-08-01

    Preliminary characterization and antioxidant activity in vitro and in vivo investigation of the polysaccharide fraction named as RCSP II, which was extracted from Rana chensinensis skin, were performed. Results indicated that RCSP II comprised glucose, galactose, and mannose in a molar ratio of 87.82:2.77:1.54 with a molecular weight of 12.8 kDa. Antioxidant activity assay in vitro showed that RCSP II exhibited 75.2% scavenging activity against 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) radicals at the concentration of 2500 mg/L and 85.1% against chelated ferrous ion at 4000 mg/L. Antioxidant activity assay in vivo further showed that RCSP II increased the activities of antioxidant enzymes, decreased the levels of malondialodehyde, and enhanced total antioxidant capabilities in livers and sera of d-galactose induced mice. These results suggested that RCSP II could have potential antioxidant applications as medicine or functional food.

  20. Effect of rana galamensis–based diet on the activities of some enzymes and histopathology of selected tissues of albino rats

    Directory of Open Access Journals (Sweden)

    Basiru Olaitan Ajiboye

    2016-10-01

    Full Text Available The effect of Rana galamensis-based diet on the activities of some enzymes and histopathology of selected tissues of albino rats was investigated for eight weeks. A total of sixteen albino rats weighing between 29.15 and 26.01g (21 days old were divided into two groups. The first group contains animals fed on casein-based diet (control; the second group was fed on Rana galamensis-based diet. The animals were fed with their appropriate diet on daily basis and on the eight weeks of the experiment the animals were sacrificed using diethyl ether as anesthesia, blood was collected by cardiac puncture and organs of interest were harvested. Thereafter, organ to body weight ratio, some biochemical parameters and histopathology examination were carried out. There was no significant difference (p >0.05 in the organ to body weight ratio of the animals fed on control and Rana galamensis-based diets. Also, there was no significant different (p >0.05 in the activities of all the enzymes (ALP [alkaline phosphatase], AST [asparate transaminase], ALT [alanine transaminase], and γGT [gamma glutamyl transferase] investigated in the selected tissues and serum of rats fed on Rana galamensis- based diet when compared with the control. In addition, histological examinations of hepatocyte's rats fed on Rana galamensis- based diet show normal architecture structure when compared with the control. The insignificant different in the activities of all the enzymes studies (ALP, AST, ALT and γGT indicated no organ damage, supported by the normal histology studies. The obtained results may imply that Rana galamensis is safe for consumption.  Normal 0 false false false EN-US X-NONE X-NONE

  1. 哈士蟆治疗脓毒血症的可行性分析%Possibility analysis of Rana Temporaria chensinensis Dacid applied in pyemia

    Institute of Scientific and Technical Information of China (English)

    张娴; 盛颖

    2015-01-01

    To discuss the pathogenesis,Chinese and west medical curing method and pharmacology of Rana Temporaria chensinensis Dacid applied in pyemia,and to raise the possibility of Rana Temporaria chensinensis Dacid applied in pyemia.%探讨了脓毒血症的病机、中西医治法以及哈士蟆应用于脓毒血症的药理研究,提出哈士蟆治疗脓毒血症的可行性。

  2. Polypeptides from the Skin of Rana chensinensis Exert the Antioxidant and Antiapoptotic Activities on HaCaT Cells.

    Science.gov (United States)

    Zhang, Xin; Cheng, Yunyun; Yang, Yang; Liu, Songcai; Shi, Hui; Lu, Chao; Li, Siming; Nie, Linyan; Su, Dan; Deng, Xuming; Ding, Kexiang; Hao, Linlin

    2017-01-02

    Studies have shown that frog skin secretes many types of peptides that are good for human skin. In this study, acid and enzymatic extracts of Rana skin peptides (acid/enzymatic Rana skin peptides, ARPs/ERPs) were obtained. The chemical and physical properties of the ARPs and ERPs were identified through UV scanning, HGLC, FRIT, and MS. MTS and flow cytometry were used to test the proproliferative and antiapoptotic effects of the ARPs and ERPs on human immortalized keratinocytes (HaCaT cells). To elucidate the antiapoptotic mechanisms, the mRNA and protein levels of EGF (epidermal growth factor, which enhances stimulation of cellular proliferation in both cells and epithelial tissues) and caspase-3 were evaluated using quantitative RT-PCR. The results indicated that the ARPs and ERPs were extracted from the Rana skin with yields of 0.65% and 0.52%, respectively. Treatment with ARPs (1.6 g/L) and ERPs (0.8 g/L) showed a 1.66-fold (p < 0.001) and 2.1-fold (p < 0.001) enhancement in the proliferation rates of HaCaT cells. The rate of apoptosis decreased by 2.6 fold (p < 0.01) and 3.4 fold (p < 0.01) under the UVB stimulation, respectively, at the same time, the up-regulation of EGF and down-regulation of caspase-3 were found. These results suggested that we can dig into the potential value of ARPs/ERPs in a new field.

  3. Hexadactyly case at a Rana kl. esculenta sample from the north-western part of Romania (Short Notes

    Directory of Open Access Journals (Sweden)

    Istvan SAS

    2006-05-01

    Full Text Available At 17 June 2006, in a habitat close to Gherta Mica locality (47°56'0'' N, 23°14'0'' E, Satu-Mare County, Romania we had found a sample of Rana kl. esculenta which presented hexadactyly at both of its posterior feet. The captured sample of edible frog had fully formed extra (sixth toes, with phalanges (bones. The hexadactyly was perfectly symmetrical at both of the posterior feet. At this individual we did not discovered any other malformations, the biometrical characters situating in the variations limits of the other green frogs from the studied habitat. A symmetric hexadacytly can be a result of atavism.

  4. [Bio-acoustic investigations in the green frog, rana esculenta (L.)].

    Science.gov (United States)

    Wahl, Manfred

    1969-07-01

    1. At a pond near Tübingen, West-Germany, the calling period of the green frog, Rana esculenta, lasts for a period ranging from the middle to the end of April, to the beginning to the end of July. The calling period is parted because of two changes in the behavior of calling and the changing number of the calling groups in: pre spawning period, spawning period and post spawning period. 2. Male frogs form calling groups. The males of each group cry in a rhythmic chorus. 3. The calling activity is influenced by 3 external factors, weather, water temperature and temperature of the air. The dependance of calling activity by these factors is not linear. During a period of good weather the calling activity increases daily. During a period of bad weather there is a daily decrease. The highest calling activity is on sunny days with a water temperature of between 17.5 and 22°C plus or minus 1 degree. From this level the activity falls with decreasing or increasing water temperature asymptotic to zero. The lower limit of calling activity ranges from 10 to 12°C, the upper one by 36.5 plus or minus 0.5°C. With the growing increase of air temperature the number of calls per time period falls asymptotic to zero. 4. The male green frog emits 6 calls; one mating call, two territorial calls, two release calls and one distress call. The calls consist of impulses, which, in the case of the mating call, are arranged to characteristic impulse-groups. The female green frog also emits calls, but no mating calls. 5. The parameters of mating and territorial calls are influenced by the water temperature. With increasing water temperature the duration of calls decreases linear, on the other hand the sequence of impulses and the repetition rate of impulse-groups show a positive linear regression. Also the size of the frog influences the calling parameters. With the increase of body length the duration of mating calls and territorial calls decreases and the sequence of impulses increases

  5. Impacts of weathered tire debris on the development of Rana sylvatica larvae

    Science.gov (United States)

    Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

    2009-01-01

    Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

  6. 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

  7. Effects of wetland vs. landscape variables on parasite communities of Rana pipiens: links to anthropogenic factors

    Science.gov (United States)

    Schotthoefer, Anna M.; Rohr, Jason R.; Cole, Rebecca A.; Koehler, Anson V.; Johnson, Catherine M.; Johnson, Lucinda B.; Beasley, Val R.

    2011-01-01

    The emergence of several diseases affecting amphibian populations worldwide has prompted investigations into determinants of the occurrence and abundance of parasites in frogs. To understand the spatial scales and identify specific environmental factors that determine risks of parasitism in frogs, helminth communities in metamorphic frogs of the northern leopard frog (Rana pipiens) were examined in relation to wetland and landscape factors at local (1 km) and regional (10 km) spatial extents in an agricultural region of Minnesota (USA) using regression analyses, ordination, and variance partitioning techniques. Greater amounts of forested and woody wetland habitats, shorter distances between woody wetlands, and smaller-sized open water patches in surrounding landscapes were the most consistently positive correlates with the abundances, richness, and diversity of helminths found in the frogs. Wetland and local landscape variables were suggested as most important for larval trematode abundances, whereas local and regional landscape variables appeared most important for adult helminths. As previously reported, the sum concentration of atrazine and its metabolite desethylatrazine, was the strongest predictor of larval trematode communities. In this report, we highlight the additional influences of landscape factors. In particular, our data suggest that anthropogenic activities that have resulted in the loss of the availability and connectivity of suitable habitats in the surrounding landscapes of wetlands are associated with declines in helminth richness and abundance, but that alteration of wetland water quality through eutrophication or pesticide contamination may facilitate the transmission of certain parasite taxa when they are present at wetlands. Although additional research is needed to quantify the negative effects of parasitism on frog populations, efforts to reduce inputs of agrochemicals into wetlands to limit larval trematode infections may be warranted

  8. Dynamics of testis-ova in a wild population of Japanese pond frogs, Rana nigromaculata.

    Science.gov (United States)

    Kobayashi, Tohru; Kumakura, Masahiko; Yoshie, Sumio; Sugishima, Tomomi; Horie, Yoshifumi

    2015-02-01

    Although many studies have reported the occurrence of testis-ova in wild frog populations, the origin and trigger of testis-ova differentiation/development remain unclear. A high frequency of testis-ova has been previously reported for wild populations of the Japanese pond frog, Rana nigromaculata (cf. Iwasawa and Asai, '59). In the present study, we aimed to clarify the dynamics of testis-ova in this frog species, including the origin and artificial induction of testis-ova. Testis-ova were observed in both mature frogs and puberty-stage frogs (i.e., 0- and 1-year-old frogs). However, the early stages of testis-ova (~pachytene stage) were mostly observed in puberty-stage male frogs at the onset of spermatogenesis. The early stages of testis-ova were observed in the cysts of early secondary spermatogonia and the single cysts of the primary spermatogonium. This finding indicates that testis-ova differentiation occurs during spermatogonial proliferation and that it is correlated with the initiation of spermatogenesis. We also examined whether estrogen exposure induced testis-ova differentiation and how it is correlated with the progression of spermatogenesis. When 1-year-old frogs were exposed to estradiol-17β during spring (i.e., when spermatogenesis was initiated), testis-ova differentiation was induced in a dose-dependent manner. However, this phenomenon did not occur in 1-year-old frogs during summer, (i.e., when the transition from spermatogonia to spermatocytes mainly occurs). These results present the first evidence that testis-ova of the Japanese pond frog are derived from primary and early secondary spermatogonia, and that estrogen exposure induces testis-ova differentiation accompanied by the initiation of spermatogenesis.

  9. Molecular cloning and characterization of oocyte-specific Pat1a in Rana rugosa frogs.

    Science.gov (United States)

    Nakamura, Yoriko; Iwasaki, Takehiro; Umei, Yosuke; Saotome, Kazuhiro; Nakajima, Yukiko; Kitahara, Shoichi; Uno, Yoshinobu; Matsuda, Yoichi; Oike, Akira; Kodama, Maho; Nakamura, Masahisa

    2015-10-01

    The Pat1 gene is expressed in the immature oocytes of Xenopus, and is reportedly involved in regulating the translation of maternal mRNAs required for oocyte-maturation. However, it is still unknown when Pat1a first appears in the differentiating ovary of amphibians. To address this issue, we isolated the full-length Pat1a cDNA from the frog Rana rugosa and examined its expression in the differentiating ovary of this frog. Among eight different tissues examined, the Pat1a mRNA was detectable in only the ovary. When frozen sections from the ovaries of tadpoles at various stages of development were immunostained for Vasa-a germ cell-specific protein-and Pat1a, Vasa-immunopositive signals were observed in all of the germ cells, whereas Pat1a signals were confined to the growing oocytes (50-200 μm in diameter), and absent from small germ cells (<50 μm in diameter). Forty days after testosterone injection into tadpoles to induce female-to-male sex-reversal, Pat1a-immunoreactive oocytes had disappeared completely from the sex-reversed gonad, but Vasa-positive small germ cells persisted. Thus, Pat1a would be a good marker for identifying the sexual status of the sex-reversing gonad in amphibians. In addition, fluorescence in situ hybridization analysis showed Pat1a to have an autosomal locus, suggesting that Pat1a transcription is probably regulated by a tissue-specific transcription factor in R. rugosa.

  10. Within-population polymorphism of sex-determination systems in the common frog (Rana temporaria).

    Science.gov (United States)

    Rodrigues, N; Betto-Colliard, C; Jourdan-Pineau, H; Perrin, N

    2013-07-01

    In sharp contrast with birds and mammals, the sex chromosomes of ectothermic vertebrates are often undifferentiated, for reasons that remain debated. A linkage map was recently published for Rana temporaria (Linnaeus, 1758) from Fennoscandia (Eastern European lineage), with a proposed sex-determining role for linkage group 2 (LG2). We analysed linkage patterns in lowland and highland populations from Switzerland (Western European lineage), with special focus on LG2. Sibship analyses showed large differences from the Fennoscandian map in terms of recombination rates and loci order, pointing to large-scale inversions or translocations. All linkage groups displayed extreme heterochiasmy (total map length was 12.2 cM in males, versus 869.8 cM in females). Sex determination was polymorphic within populations: a majority of families (with equal sex ratios) showed a strong correlation between offspring phenotypic sex and LG2 paternal haplotypes, whereas other families (some of which with female-biased sex ratios) did not show any correlation. The factors determining sex in the latter could not be identified. This coexistence of several sex-determination systems should induce frequent recombination of X and Y haplotypes, even in the absence of male recombination. Accordingly, we found no sex differences in allelic frequencies on LG2 markers among wild-caught male and female adults, except in one high-altitude population, where nonrecombinant Y haplotypes suggest sex to be entirely determined by LG2. Multifactorial sex determination certainly contributes to the lack of sex-chromosome differentiation in amphibians. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  11. Effects of six chemical deicers on larval wood frogs (Rana sylvatica).

    Science.gov (United States)

    Harless, Meagan L; Huckins, Casey J; Grant, Jacqualine B; Pypker, Thomas G

    2011-07-01

    Widespread and intensive application of road deicers, primarily road salt (NaCl), in North America threatens water quality and the health of freshwater ecosystems. Intensive use of NaCl can be harmful to sensitive members of freshwater ecosystems such as amphibians. Detection of negative effects of NaCl application has prompted the search for alternative chemical deicers with lower environmental impacts. We conducted a series of 96-h acute toxicity tests to determine the negative sensitivity of larval wood frogs (Rana [Lithobates] sylvatica) to six deicing chemicals: urea (CH(4) N(2) O), sodium chloride (NaCl), magnesium chloride (MgCl(2) ), potassium acetate (CH(3) COOK), calcium chloride (CaCl(2) ), and calcium magnesium acetate (C(8) H(12) CaMgO(8) ). Acetates are sometimes touted as environmentally friendly alternatives to NaCl but have not been examined in enough detail to warrant this designation. When exposed to a range of environmentally realistic concentrations of these chemicals, larvae were least sensitive (i.e., had the lowest mortality rate) to CH(4) N(2) O, NaCl, and MgCl(2) and most sensitive to acetates (C(8) H(12) CaMgO(8) , CH(3) COOK) and CaCl(2) . Our observed median lethal concentration estimates (LC50(96-h) ) for NaCl were over two times higher than values presented in previous studies, which suggests variability in tolerance among R. sylvatica populations. The deicers varied greatly in their toxicity, and further research is warranted to examine the differential effects of this suite of deicers on other species.

  12. Female choice for males with greater fertilization success in the Swedish Moor frog, Rana arvalis.

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    Craig D H Sherman

    Full Text Available BACKGROUND: Studies of mate choice in anuran amphibians have shown female preference for a wide range of male traits despite females gaining no direct resources from males (i.e. non-resource based mating system. Nevertheless, theoretical and empirical studies have shown that females may still gain indirect genetic benefits from choosing males of higher genetic quality and thereby increase their reproductive success. METHODOLOGY/PRINCIPAL FINDINGS: We investigated two components of sexual selection in the Moor frog (Rana arvalis, pre-copulatory female choice between two males of different size ('large' vs. 'small', and their fertilization success in sperm competition and in isolation. Females' showed no significant preference for male size (13 small and six large male preferences but associated preferentially with the male that subsequently was the most successful at fertilizing her eggs in isolation. Siring success of males in competitive fertilizations was unrelated to genetic similarity with the female and we detected no effect of sperm viability on fertilization success. There was, however, a strong positive association between a male's innate fertilization ability with a female and his siring success in sperm competition. We also detected a strong negative effect of a male's thumb length on his competitive siring success. CONCLUSIONS/SIGNIFICANCE: Our results show that females show no preference for male size but are still able to choose males which have greater fertilization success. Genetic similarity and differences in the proportion of viable sperm within a males ejaculate do not appear to affect siring success. These results could be explained through pre- and/or postcopulatory choice for genetic benefits and suggest that females are able to perceive the genetic quality of males, possibly basing their choice on multiple phenotypic male traits.

  13. Toxic Effects of Three Heavy Metallic Ions on Rana zhenhaiensis Tadpoles

    Institute of Scientific and Technical Information of China (English)

    Li WEI; Guohua DING; Sainan GUO; Meiling TONG; Wenjun CHEN; Jon FLANDERS; Weiwei SHAO; Zhihua LIN

    2015-01-01

    Heavy metal pollution is widespread in some areas of China and results in contamination of land, water, and air with which all living organisms interact. In this study, we used three heavy metallic ions (Cu2+, Pb2+ and Zn2+) to assess their toxicity effects on mortality, blood biomarker and growth traits (body length and body mass) of Rana zhenhaiensis tadpoles. The results showed that the toxicity levels of the three metallic ions were different when conducted with different experiment designs. For acute toxicity tests, Cu2+ was the most toxic with the highest tadpole mortality. The mortalities of tadpoles showed significant differences among the treatments at the same exposure time endpoints (24, 48, 72 and 96h). Results from repeated measures ANOVA indicated that metallic ion concentration, exposure time and their interactions significantly affected the mortalities of R. zhenhaiensis tadpoles. Also, the toxicity effects of all binary combinations of the three metallic ion treatments showed synergism. The half lethal concentrations (LC50) decreased with increasing exposure time during the experimental period, and the safe concentration (SC)values of Cu2+, Pb2+ and Zn2+ were different from each other. Combined and compared LC50 values with previous data reported, it is suggestes that the toxicity levels of metal pollution to anuran tadpoles should be species-and age-related. For blood biomarker tests, Zn2+ was the most toxic with the highest total frequencies of abnormal erythrocytic nucleus. All three metallic ions caused higher abnormal erythrocytic nucleus compared with control groups. In a chronic toxicity test, Pb2+ was the most toxic with lowest growth traits. Survival rate (except for 18 days), total body length and body mass showed significant differences among the treatments. These findings indicated that tadpoles of R. zhenhaiensis should be as a bioindicator of heavy metals pollution.

  14. Regulation of SMAD transcription factors during freezing in the freeze tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    Aguilar, Oscar A; Hadj-Moussa, Hanane; Storey, Kenneth B

    2016-11-01

    The wood frog, Rana sylvatica, survives sub-zero winter temperatures by undergoing full body freezing for weeks at a time, during which it displays no measurable brain activity, no breathing, and a flat-lined heart. Freezing is a hypometabolic state characterized by a global suppression of gene expression that is elicited in part by transcription factors that coordinate the activation of vital pro-survival pathways. Smad transcription factors respond to TGF-β signalling and are involved in numerous cellular functions from development to stress. Given the identity of genes they regulate, we hypothesized that they may be involved in coordinating gene expression during freezing. Protein expression of Smad1/2/3/4/5 in response to freezing was examined in 24h frozen and 8h thawed wood frog tissues using western immunoblotting, with the determination of subcellular localization in muscle and liver tissues. Transcript levels of smad2, smad4 and downstream genes (serpine1, myostatin, and tsc22d3) were measured by RT-PCR. Tissue-specific responses were observed during freezing where brain, heart, and liver had elevated levels of pSmad3, and skeletal muscle and kidneys had increased levels of pSmad1/5 and pSmad2 during freeze/thaw cycle, while protein and transcript levels remained constant. There were increases in nuclear levels of pSmad2 in muscle and pSmad3 in liver. Transcript levels of serpine1 were induced in heart, muscle, and liver, myostatin in muscle, and tsc22d3 in heart, and liver during freezing. These results suggest a novel freeze-responsive activation of Smad proteins that may play an important role in coordinating pro-survival gene networks necessary for freeze tolerance.

  15. Dmrt1 polymorphism covaries with sex-determination patterns in Rana temporaria.

    Science.gov (United States)

    Ma, Wen-Juan; Rodrigues, Nicolas; Sermier, Roberto; Brelsford, Alan; Perrin, Nicolas

    2016-08-01

    Patterns of sex-chromosome differentiation and gonadal development have been shown to vary among populations of Rana temporaria along a latitudinal transect in Sweden. Frogs from the northern-boreal population of Ammarnäs displayed well-differentiated X and Y haplotypes, early gonadal differentiation, and a perfect match between phenotypic and genotypic sex. In contrast, no differentiated Y haplotypes could be detected in the southern population of Tvedöra, where juveniles furthermore showed delayed gonadal differentiation. Here, we show that Dmrt1, a gene that plays a key role in sex determination and sexual development across all metazoans, displays significant sex differentiation in Tvedöra, with a Y-specific haplotype distinct from Ammarnäs. The differential segment is not only much shorter in Tvedöra than in Ammarnäs, it is also less differentiated and associates with both delayed gonadal differentiation and imperfect match between phenotypic and genotypic sex. Whereas Tvedöra juveniles with a local Y haplotype tend to ultimately develop as males, those without it may nevertheless become functional XX males, but with strongly female-biased progeny. Our findings suggest that the variance in patterns of sex determination documented in common frogs might result from a genetic polymorphism within a small genomic region that contains Dmrt1. They also substantiate the view that recurrent convergences of sex determination toward a limited set of chromosome pairs may result from the co-option of small genomic regions that harbor key genes from the sex-determination pathway.

  16. Toxic effects of endrin and toxaphene on the southern leopard frog Rana sphenocephala

    Science.gov (United States)

    Hall, R.J.; Swineford, D.

    1980-01-01

    Eggs, larvae and sub-adults of the southern leopard frog Rana sphenocephala were exposed to endrin and toxaphene. Exposure was in water by a continuous-flow technique, following standards that have been used successfully in the study of fish and invertebrates. R. sphenocephala is more sensitive to both pesticides than are higher vertebrates but is slightly less sensitive than fish. Eggs seem to be resistant to the effects of both pesticides and are probably poor indicators of environmental hazard. The toxic level of endrin is about equal in larvae and transformed frogs (LC50, 0?005-0?015 ppm). Toxaphene is less toxic to sub-adults (LC50, 0?37-0?790 ppm) than to larvae (LC50, 0?032-0?054 ppm). Delayed mortality, behavioural aberrations and effects on growth have been seen in toxaphene-dosed larvae observed over 30-day periods. Behavioural effects are more severe than those reported in other groups of animals. Effects on growth resulting from a 96-h exposure begin in the 0?013-0?018 ppm range. The maximum accumulation of residues observed for each chemical represented bioconcentration factors of about 100. Endrin residues are apparently lost more readily than toxaphene residues; relative depuration rates correlate well with the time course of toxic action in each chemical. Although less sensitive to these pesticides than fish, amphibians may not be protected in their natural habitats. Future studies of the effects of toxicants on amphibians should employ larvae if only one stage can be tested, should expose subjects for at least 96 h and should continue observations for a total of at least 30 days.

  17. Behavioral Responses of Northern Leopard Frogs (Rana pipiens to Roads and Traffic: Implications for Population Persistence

    Directory of Open Access Journals (Sweden)

    Julie Bouchard

    2009-12-01

    Full Text Available A key goal in road ecology is to determine which species are most vulnerable to the negative effects of roads on population persistence. Theory suggests that species that avoid roads are less likely to be negatively affected by roads than those that do not avoid roads. The goal of this study was to take a step toward testing this prediction by evaluating the behavioral response to roads and traffic of a species whose populations are known to be negatively affected by roads and traffic, the northern leopard frog (Rana pipiens. We studied the movement patterns of northern leopard frogs during their spring migration from overwintering sites in a river to various breeding ponds that were disconnected from the river by roads. We performed short-distance translocations of migrating frogs, followed them visually, and documented their movement coordinates following each hop, both near the roads and in non-roaded areas. We found that frogs took longer to move near roads with more traffic and that their movement was quickest in areas without roads nearby. Frogs tended to deviate more from a straight-line course when they were released near roads than compared with control areas, but this response was independent of traffic volume. All frogs released near roads attempted to cross the road. On very low traffic roads (10.86 mean vehicles per hour, 94% of frogs crossed the road successfully, whereas at higher traffic roads (58.29 mean vehicles per hour 72% were successful. Our results suggest that frog's inability to avoid going onto roads and their slow movement combine to make them particularly vulnerable to road mortality, which likely explains the strong negative effects of roads on frog population abundance. Conservation efforts should focus on preventing frogs from accessing the road surface through the use of drift fencing and culverts.

  18. D-Asp: a new player in reproductive endocrinology of the amphibian Rana esculenta.

    Science.gov (United States)

    Raucci, Franca; Di Fiore, Maria Maddalena

    2011-11-01

    We investigated the involvement of D-Aspartic acid (D-Asp) on ovarian and testicular morphology of the green frog, Rana esculenta, and its effect on the testosterone production. The study has been performed throughout the reproductive cycle. In both ovary and testis a substantial amount of D-Asp is endogenously present and its concentration varies as function of reproduction. In the frog, D-Asp content is differently correlated with gonadal and plasmatic levels of testosterone, depending on the sex. In fact, the amount of the D-Asp is inversely linked with that of the testosterone in the ovary, while this correlation directly matched in the testis. In vivo short-term experiments, consisting of a single intra-peritoneal injection of D-Asp (2.0 μmol/g body weight), demonstrated that the enantiomer is significantly accumulated by both the ovary and testis, reaching after 3 h the highest uptake and thereafter decreasing to baseline values within 24 h. Furthermore, D-Asp influences the synthesis and/or the release of testosterone, causing a decrease of its level in the female, and an increase in the male, respectively. In vivo long-term experiments, D-Asp, chronically administered to the frogs of both sexes, enhances the maturation of both gonads, determining in the oocytes an higher accumulation of carbohydrate yolk plates in the ooplasm, and stimulating the spermatogenesis in the testis. Taken altogether, our results show that D-Asp operates differently in female and male frog gonads, indicating that it has different targets in the reproductive machinery depending on the sex. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Hybridization and mitochondrial genome introgression between Rana chensinensis and R. kukunoris.

    Science.gov (United States)

    Qi, Yin; Lu, Bin; Gao, Haiyan; Hu, Ping; Fu, Jinzhong

    2014-11-01

    Mitochondrial genome (mito-genome) introgression among metazoans is commonplace, and several biological processes may promote such introgression. We examined two proposed processes for the mito-genome introgression between Rana chensinensis and R. kukunoris: natural hybridization and sex-biased dispersal. We sampled 477 individuals from 28 sites in the potential hybrid zone in the western Tsinling Mountains. Mitochondrial gene (cyt-b) trees were used to examine the introgression events. Microsatellite DNA loci, cyt-b and morphological data were used to identify hybrids and to examine the extent of natural hybridization. We detected rampant bidirectional introgressions, both ancient and recent, between the two species. Furthermore, we found a wide hybrid zone, and frequent and asymmetric hybridization. The hybrid zone cline analysis revealed a clear mitochondrial-nuclear discordance; while most nuclear markers displayed similar and steep clines, cyt-b had a displaced cline centre and a more gradual and wider cline. We also detected strong and asymmetric historical maternal gene flow across the hybrid zone. This widespread hybridization and detected low mito-nuclear conflicts may, at least partially, explain the high frequency of introgression. Lastly, microsatellite data and population genetic methods were used to assess sex-biased dispersal. A weak pattern of female-biased dispersal was detected in both species, suggesting it may not play an important role in the observed introgression. Our data are consistent with the hybridization hypothesis, but support for the sex-biased dispersal hypothesis is weak. We further suggest that selective advantages of the R. kukunoris-type mito-genome in thermal adaptation may also contribute to the introgression between the two species. © 2014 John Wiley & Sons Ltd.

  20. Independent degeneration of W and Y sex chromosomes in frog Rana rugosa.

    Science.gov (United States)

    Miura, Ikuo; Ohtani, Hiromi; Ogata, Mitsuaki

    2012-01-01

    The frog Rana rugosa uniquely possesses two different sex-determining systems of XX/XY and ZZ/ZW, separately in the geographic populations. The sex chromosomes of both types share the same origin at chromosome 7, and the structural differences between X and Y or Z and W were evolved through two inversions. In order to ascertain the mechanisms of degeneration of W and Y chromosomes, we gynogenetically produced homozygous diploids WW and YY and examined their viability. Tadpoles from geographic group N (W(N)W(N)) containing three populations died of edema at an early developmental stage within 10 days after hatching, while tadpoles from the geographic group K (W(K)W(K)) that contained two populations died of underdeveloped growth at a much later stage, 40-50 days after fertilization. On the contrary, W(N)W(K) and W(K)W(N) hybrid embryos were viable, successfully passed the two lethal stages, and survived till the attainment of adulthood. The observed survival implies that the lethal genes of the W chromosomes are not shared by the two groups and thus demonstrates their independent degeneration histories between the local groups. In sharp contrast, a sex-linked gene of androgen receptor gene (AR) from the W chromosome was down-regulated in expression in both the groups, suggesting that inactivation of the W-AR allele preceded divergence of the two groups and appearance of the lethal genes. Besides, the YY embryos died of cardiac edema immediately after hatching. The symptom of lethality and the stage of developmental arrest differed from those for either of WW lethal embryos. We therefore conclude that the W and Y chromosomes involve no evolutionary common scenario for degeneration.

  1. A new gorgoderid species of the urinary bladder of Rana zweifeli from Michoacán, Mexico Una nueva especie de gorgodérido de la vejiga urinaria de Rana zweifeli de Michoacán, México

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    Rosario Mata-López

    2006-12-01

    Full Text Available Gorgoderina tarascae n. sp. is described from the urinary bladder of Rana zweifeli, from Cutzaróndiro, Michoacán, Mexico. Gorgoderina tarascae differs from the other species of the genus by possessing the following combination of characters: follicular vitelline glands, arranged in two clusters of 4-7 follicles dorsal to the ovary, compact and smooth reproductive organs situated far from each other and from the acetabulum, suckers close to each other, and a slender, spindle shaped body with a flexed position due to the situation of the acetabulum.Gorgoderina tarascae n. sp. se describe como parásita de la vejiga urinaria de Rana zweifeli de Cutzaróndiro, Michoacán, México. Gorgoderina tarascae difiere del resto de las especies del género por la siguiente combinación de características: posee glándulas vitelógenas arregladas en dos racimos de 4-7 folículos situados dorsalmente al ovario, órganos reproductivos compactos y de bordes lisos, muy separados entre si y con respecto del acetábulo, ventosas cercanas una de la otra y cuerpo delgado, en forma de huso y flexionado debido a la posición del acetábulo.

  2. Can an Invasive Prey Species Induce Morphological and Behavioral Changes in an Endemic Predator? Evidence from a South Korean Snake (Oocatochus rufodorsatus)

    Institute of Scientific and Technical Information of China (English)

    Jun-Haeng HEO; Heon-Joo LEE; Il-Hun KIM; Jonathan J FONG; Ja-Kyeong KIM; Sumin JEONG; Daesik PARK

    2014-01-01

    Introduction of an invasive prey species into an ecosystem may affect an endemic predator’s fitness by altering the prey-predator system. Successful adaptation may allow the endemic predator to eat and control the invasive species, while unsuccessful adaptation may result in extinction of the predator. We examine the possible effects of the invasive North American bullfrog (Rana [Lithobates] catesbeiana) on the endemic Red-backed rat snake (Oocatochus rufodorsatus) in South Korea. We do so by comparing the morphology and behavior of adult and hatchling snakes from bullfrog-exposed (Taean) and bullfrog-unexposed (Hongcheon) populations. Among the seven morphological characteristics investigated, relative tail length (tail length/snout-vent length) of both adults and hatchlings from Taean was significantly greater than that of adults and hatchlings from Hongcheon. Also, adult snakes from Taean had a signiifcantly shorter latency of ifrst tongue lfick in response to prey compared to adults from Hongcheon. This difference was not observed in hatchlings. In other snake species, a longer relative tail length and shorter latency of ifrst tongue lfick are known to improve foraging efifciency, and these characters may be adaptations ofO. rufodorsatus to prey on bullfrogs. This study provides preliminary evidence that the presence of an invasive prey species may cause morphological and behavioral changes in an endemic predator.

  3. Preparation and Characterization of Vancomycin-Loaded Electrospun Rana chensinensis Skin Collagen/Poly(L-lactide Nanofibers for Drug Delivery

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    Mei Zhang

    2016-01-01

    Full Text Available Collagen was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method for the use of drug carriers. In this paper we demonstrated two different nanofiber-vancomycin (VCM systems, that is, VCM blended nanofibers and core-shell nanofibers with VCM in the core. Rana chensinensis skin collagen (RCSC and poly(L-lactide (PLLA (3 : 7 were blended in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP at a concentration of 10% (g/mL to fabricate coaxial and blend nanofibers, respectively. Coaxial and blend electrospun RCSC/PLLA nanofibers containing VCM (5 wt% were evaluated for the local and temporal delivery of VCM. The nanofiber scaffolds were characterized by environmental scanning electron microscope (ESEM, transmission electron microscopy (TEM, Fourier transform infrared spectra (FTIR, differential scanning calorimeter (DSC, water contact angle (WCA, and mechanical tests. The drug release of VCM in these two systems was compared by using UV spectrophotometer. The empirical result indicated that both the blend and coaxial RCSC/PLLA scaffolds followed sustained control release for a period of 80 hours, but the coaxial nanofiber might be a potential drug delivery material for its better mechanical properties and sustained release effect.

  4. Speciation in the Rana chensinensis species complex and its relationship to the uplift of the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Zhou, Wei-Wei; Wen, Yang; Fu, Jinzhong; Xu, Yong-Biao; Jin, Jie-Qiong; Ding, Li; Min, Mi-Sook; Che, Jing; Zhang, Ya-Ping

    2012-02-01

    Speciation remains a fundamental issue in biology. Herein, we report an investigation into speciation in the Rana chensinensis species complex using DNA sequence data from one mitochondrial and five nuclear genes. A phylogenetic analysis of the data revealed four major clades in the complex, and each of them was found to likely represent a species, including one cryptic species. Ecological niche models were generated from 19 climatic variables for three of the four major clades, which were represented by widespread sampling, including R. chensinensis, Rana kukunoris and the potential cryptic species. Each clade is associated with a unique ecological unit, and this indicates that ecological divergence probably drove speciation. Ecological divergence is likely related to the late Cenozoic orogenesis of the Qinghai-Tibetan Plateau. In addition, gene flow between species was detected but only in peripheral portions of the ranges of the four major clades, thus likely had little influence on the speciation processes. Discordances between mitochondrial and nuclear genes were also found; the nominal species, R. chensinensis, contains multiple maternal clades, suggesting potential mitochondrial introgression between R. chensinensis and R. kukunoris.

  5. Breeding ecology and oviposition site selection of black-spotted pond frogs (Rana nigromaculata) in Ningbo, China

    Institute of Scientific and Technical Information of China (English)

    Yanping WANG; Zhengjun WU; Ping LU; Fang ZHANG; Yiming LI

    2008-01-01

    The black-spotted pond frog (Rana nigromacu-lata) is one of the most widely distributed species in China. However, there have been only a few qualitative descrip-tions of their breeding ecology and oviposition site selec-tion. From 2004 to 2006, we investigated the breeding ecology and oviposition site selection of K nigromaculata in Ningbo, China, quantitatively. Analyses of breeding ecology show that: (1) mean frog density in the breeding season was 0.0903 ± 0.0029 individuals per meter (n = 11) (mean ± SE); (2) R. nigromaculata was a sexually dimorphic species, with females significantly larger than males in both body weight and snout-vent length; (3) the clutch size averaged 4643.04± 235.96 eggs (range 1546-7897, n = 50); and (4) the egg size ranged from 1.50 to 1.74 mm in diameter, with an average egg size of 1.6050 ± 0.0046 mm (n = 226). Oviposition sites differed significantly from random sites in percentages of water, bare ground and vegetation cover, water depth (cm), water temperature (°C) and water turbidity. Rana nigro-maculata preferred microhabitats with higher percentages of water and vegetation cover, while it avoided microha-bitats with deeper water. The results suggest that micro-habitats with higher percentages of water and vegetation cover, but not deeper water, should be priorities for pro-tection and conservation of the breeding habitats of R. nigromaculata.

  6. Reproduction of the exotic bullfrog Lithobates catesbeianus (Shaw, 1802 (Anura, Ranidae in creeks of the Atlantic Rainforest of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Lilian Gomes Afonso

    2010-09-01

    Full Text Available Reproduction of the exotic bullfrog Lithobates catesbeianus was studied every two months from January 2005 to December 2006, analyzing tadpoles, juveniles, and adult vocalizations at three creeks located in the largest Brazilian center of ornamental fish breeding. Absolute and relative tadpole frequencies were measured bimonthly in three development stages: G1 (no limbs, G2 (hind limbs present, G3 (fore and hind limbs and I (metamorphs. Results show that, during warmest months, a greater proportion of tadpoles in G1, G2, and G3 phases were found in Santo Antônio and Chato creeks, while G1, G3, and I phases were more common in Gavião creek. Tadpoles in G1 and G2 phases predominated in coldest months at all locations. Male calls and highest average water temperatures and rainfall were recorded at 3 streams during the hottest months. Management measures should be adopted, such as the extermination of larval and adult stages, and initiatives should be taken to prevent new re-introductions, such as: (1 installation of fences around tanks where adults are located, (2 placement of protective screens on the pipes that release waste water from tanks directly into streams, (3 capacity building and educational measures on the problems of biological invasions for staff working on ornamental fish farms.

  7. American Religion

    Institute of Scientific and Technical Information of China (English)

    田甜

    2008-01-01

    It is said that American religion,as a great part of American culture,plays an important role in American culture. It is hoped that some ideas can be obtained from this research paper,which focuses on analyzing the great impact is produced to American culture by American religion. Finally, this essay gives two useful standpoints to English learners:Understunding American religion will help understand the American history, culture and American people,and help you to communic.ate with them better. Understanding American religion will help you understand English better.

  8. 沼泽绿牛蛙致病细菌的研究%Studies on the Fatal Bacteria in the Frog Rana grylio stejneger

    Institute of Scientific and Technical Information of China (English)

    汤显春; 薛翠峰; 高智慧

    2000-01-01

    从自然患病死亡的沼泽绿牛蛙(Rana grylio stejneger)体内分离到9株细菌,对其形态及生理生化特性进行了研究,该菌为嗜水气单胞菌嗜水变种(Aeremonas hydrophila subsp.hydrophila).

  9. 金线蛙早期胚胎发育的初步观察%Early Embryonic Development in Rana plancyi

    Institute of Scientific and Technical Information of China (English)

    韩曜平; 卢祥云

    2001-01-01

    The early embryonic development in Rana plancyi was studied in constant water (20±0.5)℃ and natural temperature(21.5~ 24℃). The development process, from fertilized egg to spiracular formation can be divided into 26 stages, took 212.94 hours under the water temperature of (20±0.5)℃ and 170.95 hours under the natural temperature(21.5~24℃).The external morphological characteristics in various stages of the embryonic development were similar to those of Rana nigromaculata, but the hatching stage was later than that of Rana nigromaculata and earlier than that of Rana limnocharis.%报道了金线蛙的早期胚胎发育。自受精卵期至鳃盖完成期共分为26个时期,其发育历程及各时期胚胎外形特征与黑斑蛙基本相似,但孵化期比黑斑蛙推迟三个胚期而早于泽蛙,在水温(20±0.5)℃及常温(21.5~24℃)条件下,其胚胎发育的全时程分别为212.94 小时和170.95 小时。

  10. Directionality of auditory nerve fiber responses to pure tone stimuli in the grassfrog, Rana temporaria. I. Spike rate responses

    DEFF Research Database (Denmark)

    Jørgensen, M B; Christensen-Dalsgaard, J

    1997-01-01

    We studied the directionality of spike rate responses of auditory nerve fibers of the grassfrog, Rana temporaria, to pure tone stimuli. All auditory fibers showed spike rate directionality. The strongest directionality was seen at low frequencies (200-400 Hz), where the spike rate could change by...

  11. Interaction of an Introduced Predator with Future Effects of Climate Change in the Recruitment Dynamics of the Imperiled Sierra Nevada Yellow-legged Frog (Rana sierrae)

    Science.gov (United States)

    I Lacan; Kathleen R. Matthews; K.V. Feldman

    2008-01-01

    Between-year variation in snowpack (from 20 to 200% of average) and summer rainfall cause large fluctuations in volume of small lakes in the higher elevation (> 3000 m) Sierra Nevada, which are important habitat for the imperiled Sierra Nevada Yellow-legged Frog, Rana sierrae. Climate change (global warming) is predicted to increase these...

  12. Turning population trend monitoring into active conservation: Can we save the Cascades Frog (Rana cascadae) in the Lassen region of California?

    Science.gov (United States)

    Gary M. Fellers; Karen L. Pope; Jonathan E. Stead; Michelle S. Koo; Hartwell H. Welsh

    2007-01-01

    Monitoring the distribution, population size, and trends of declining species is necessary to evaluate their vulnerability to extinction. It is the responsibility of scientists to alert management professionals of the need for preemptive action if a species approaches imminent, regional extirpation. This is the case with Rana cascadae (Cascades Frog...

  13. Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Science.gov (United States)

    A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

    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...

  14. Directionality of auditory nerve fiber responses to pure tone stimuli in the grassfrog, Rana temporaria. II. Spike timing

    DEFF Research Database (Denmark)

    Jørgensen, M B; Christensen-Dalsgaard, J

    1997-01-01

    We studied the directionality of spike timing in the responses of single auditory nerve fibers of the grass frog, Rana temporaria, to tone burst stimulation. Both the latency of the first spike after stimulus onset and the preferred firing phase during the stimulus were studied. In addition, the ...

  15. Surveys for presence of Oregon spotted frog (Rana pretiosa): background information and field methods

    Science.gov (United States)

    Pearl, Christopher A.; Clayton, David; Turner, Lauri

    2010-01-01

    The Oregon spotted frog (Rana pretiosa) is the most aquatic of the native frogs in the Pacific Northwest. The common name derives from the pattern of black, ragged-edged spots set against a brown or red ground color on the dorsum of adult frogs. Oregon spotted frogs are generally associated with wetland complexes that have several aquatic habitat types and sizeable coverage of emergent vegetation. Like other ranid frogs native to the Northwest, Oregon spotted frogs breed in spring, larvae transform in summer of their breeding year, and adults tend to be relatively short lived (3-5 yrs). Each life stage (egg, tadpole, juvenile and adult) has characteristics that present challenges for detection. Breeding can be explosive and completed within 1-2 weeks. Egg masses are laid in aggregations, often in a few locations in large areas of potential habitat. Egg masses can develop, hatch, and disintegrate in <2 weeks during warm weather. Tadpoles can be difficult to identify, have low survival, and spend most of their 3-4 months hidden in vegetation or flocculant substrates. Juveniles and adults are often difficult to capture and can spend summers away from breeding areas. Moreover, a substantial portion of extant populations are of limited size (<100 breeding adults), and field densities of all life stages are often low. An understanding of the biology of the species and use of multiple visits are thus important for assessing presence of Oregon spotted frogs. This report is meant to be a resource for USDA Region 6 Forest Service (FS) and OR/WA Bureau of Land Management (BLM) personnel tasked with surveying for the presence of Oregon spotted frogs. Our objective was to summarize information to improve the efficiency of field surveys and increase chances of detection if frogs are present. We include overviews of historical and extant ranges of Oregon spotted frog. We briefly summarize what is known of Oregon spotted frog habitat associations and review aspects of behavior and

  16. 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

  17. 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

  18. Sound and vibration sensitivity of VIIIth nerve fibers in the grassfrog, Rana temporaria.

    Science.gov (United States)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-10-01

    We have studied the sound and vibration sensitivity of 164 amphibian papilla fibers in the VIIIth nerve of the grassfrog, Rana temporaria. The VIIIth nerve was exposed using a dorsal approach. The frogs were placed in a natural sitting posture and stimulated by free-field sound. Furthermore, the animals were stimulated with dorso-ventral vibrations, and the sound-induced vertical vibrations in the setup could be canceled by emitting vibrations in antiphase from the vibration exciter. All low-frequency fibers responded to both sound and vibration with sound thresholds from 23 dB SPL and vibration thresholds from 0.02 cm/s2. The sound and vibration sensitivity was compared for each fiber using the offset between the rate-level curves for sound and vibration stimulation as a measure of relative vibration sensitivity. When measured in this way relative vibration sensitivity decreases with frequency from 42 dB at 100 Hz to 25 dB at 400 Hz. Since sound thresholds decrease from 72 dB SPL at 100 Hz to 50 dB SPL at 400 Hz the decrease in relative vibration sensitivity reflects an increase in sound sensitivity with frequency, probably due to enhanced tympanic sensitivity at higher frequencies. In contrast, absolute vibration sensitivity is constant in most of the frequency range studied. Only small effects result from the cancellation of sound-induced vibrations. The reason for this probably is that the maximal induced vibrations in the present setup are 6-10 dB below the fibers' vibration threshold at the threshold for sound. However, these results are only valid for the present physical configuration of the setup and the high vibration-sensitivities of the fibers warrant caution whenever the auditory fibers are stimulated with free-field sound. Thus, the experiments suggest that the low-frequency sound sensitivity is not caused by sound-induced vertical vibrations. Instead, the low-frequency sound sensitivity is either tympanic or mediated through bone conduction or sound

  19. cytogenetic effects in populations of amphibians Rana arvalis living on the radio-contaminated area

    Energy Technology Data Exchange (ETDEWEB)

    Yushkova, E.; Bodnar, I.; Zainullin, V. [Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The study of the features reactions of the animals a differing complicated individual development (metamorphosis) and living in conditions of radioactive contamination is an important trend in the modern radio-ecology. This information is of interest not only from the point of view of detection the mechanisms of radiobiological effects (hyper-radiosensitivity, hormesis, radio-adaptation, etc.) but also viewpoint of predicting delayed radiation effects that is necessary at account the normalization of technogeneous loading on natural ecosystems. An assessment of the level of cytogenetic damages (single-strand and double-strand DNA breaks) in the blood cells of tadpoles of Rana arvalis living in areas contaminated of wastes radium production (Russia, Komi Republic, Ukhta district) was conducted. Using this biological matter as a bioindicator due to the fact that development amphibian is carried out by metamorphosis and includes larval stage. At this stage post-embryonic development of an individual are the most sensitive to anthropogenic impact. To exclude the effects of other factors (temperature, age-specific peculiarities, overpopulation, etc.) on the formation of DNA damages from the studied reservoirs were taken laying eggs of amphibians (12-15 egg laying from the area) which afterwards are contain in strictly controlled laboratory conditions using water, belt silt, plants of native pond. The reaction of amphibians on the contamination was assessed by the level of DNA damage by method Comet assay was determined. With each egg laying were selected for 7 even-aged individuals. Total for cytogenetic analysis was used 189 individuals. It is shown that in animals that develop on the radio-contaminated area the level of single-strand DNA (alkaline pH version of the Comet assay) was higher than in the control area. According an estimate to the level of double-strand DNA (neutral pH version of the Comet assay) significant differences not was found. The high variability

  20. Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

    Directory of Open Access Journals (Sweden)

    S. Austin eHammond

    2013-11-01

    Full Text Available Nanoparticles (NPs, materials that have one dimension less than 100 nm, are used in manufacturing, health and food products, and consumer products including cosmetics, clothing and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs, thyroxine and 3,3’,5-triiodothyronine (T3, are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs. We used the cultured tailfin (C-fin assay to examine the exposure effects of 0.1-10 nM (~8-800 ng/L of three types of ~20 nm TiO2 NPs (P25, M212, M262 and micron-sized TiO2 (μTiO2 ±10 nM T3. The actual Ti levels were 40.9 – 64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR was used to measure the relative amounts of mRNA transcripts encoding TH-responsive thyroid hormone receptors (thra and thrb and Rana larval keratin type I (rlk1, as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30, superoxide dismutase (sod, and catalase (cat. The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25 and M212 while no effect was observed with M262 exposure. Therefore the risk of adversely affecting amphibian tissue by disrupting TH-signalling or inducing cellular stress is low for these compounds relative to other previously

  1. [Morphological and physiological characterization of fiber types in the iliofibular muscle of Rana esculenta].

    Science.gov (United States)

    Dauber, W

    1977-01-01

    In both longitudinal and cross sections of the M. iliofibularis of Rana esculenta three types of muscle fibres are identified by means of light and electron microscopy. These fibretypes called A-, B- and C-fibres are according to the fibres of m. rectus abdominis of the frog. They can be compared with the fibres of the m. rectus abdominis of rat and mouse. But there is another distribution of the fibretypes A, B and C in the m. iliofibularis and in the m. rectus abdominis. The m. iliofibularis is divided into two parts called "Tonusbündel" and "nichttonischer Teil" by means of their reaction to acetylcholine. The surface of the "Tonusbündel" consists of A-, B- and C-fibres while its inside is onlyformed by A- and B-fibres. They continue the "Tonusbündel" in the "nichttonischer Teil". This part chiefly consists of A-fibres. In cross sections their myofibrils are larger in their extent than the A-fibres known before. Therefore the A-fibretype has to be distinguished into two A-fibres: A1 and A2. The new one is called A2-fibre. A1-fibre is described in the "Tonusbündel" and in further investigations. The difference between the two fibres can be understood as a greater manifestation of power of the A1-fibre. The surface of the "nichttonischer Teil" of the m. iliofibularis consists of A2-fibres which easily could be found opposite the "Tonusbündel". At this point in contrary to the "Tonusbündel" could be found a defined morphological substrate for physiological investigations. The different reactions of "Tonusbündel" and "nichttonischer Teil" to acetylcholine could only be explained by the sum of reactions of all fibretypes in each bundle in correspondence with the reaction of the fibres in the neighbour bundle. But their different behaviour by summer- and winterfrogs is unknown. Therefore it is to discuss whether it is allowed to refer generally the results to "muscle" or "musclefibre" got from frogs living in cooled rooms. It is known in literature that not all

  2. Morphological changes in the skin of Rana pipiens in response to metabolic acidosis.

    Science.gov (United States)

    Page, R D; Frazier, L W

    1987-04-01

    The skin of Rana pipiens excretes H+ and this excretion is increased by metabolic acidosis. The mitochondria-rich (MR) cells of the skin have been found to mediate this H+ transport. The purpose of this study was to determine if there is a change in the MR cells of the skin during metabolic acidosis and if the isolated split epithelia of frog skin maintains its capacity to excrete H+. Metabolic acidosis was induced by injecting 120 mM NH4Cl (0.025 ml/g body wt) into the dorsal lymph sac three times a day for 2 days. The frogs were sacrificed and collagenase-split skins from the abdomen of normal and metabolic acidotic frogs were mounted between 2-ml chambers. H+ fluxes into both the mucosal and serosal media were measured and reported in units of (nmol) (cm2)-1 (min)-1. An increase in H+ flux was seen on both the mucosal and serosal sides of the acidotic split skins. The isolated epithelia were fixed, postosmicated, and dehydrated in the chamber. They were then embedded in Spurr's resin and 1-micron sections were cut and stained with Paragon multiple stain. Coded slides were used to count various cell types. Sections were randomly selected and approximately 40,000 cells were counted. Four basic cell types were noted and confirmed by TEM photomicrographs; basal (B) cells, granular (G) cells, keratinized cells, and MR cells. The ratio of G + B cells:MR cells in the normal skins was 1.0:0.021. The ratio in acidotic skins was 1.0:0.34. The average percentage of cell population of MR cells in the normal skins was 2.08 + 0.18 and in acidotic skins 3.20 + 0.36 (P less than 0.005). We conclude that the split skin maintains the capacity to acidify the mucosal fluid. Additionally, during metabolic acidosis there is an increased number of MR cells in the skin and this increase may be an adaptive mechanism of the skin to excrete excess H+ during acidosis.

  3. Morphometric discrimination of wild from farmed Dybowski's frog (Rana dybowskii) based on hindlimb length

    Institute of Scientific and Technical Information of China (English)

    XIA Rui; HUANG Xiao-ming; YANG Shu-hui; XU Yan-chun; Ying Lu; Thomas D.Dahmer

    2011-01-01

    Commercial farming of anuran species that arc declining in the wild raises a need to discriminate wild from farmed frogs. We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity of jumping relative to farmed frogs, highlighting a morphometric approach to discrimination of wild from farmed frogs using hindiimb length. In the present study, Dybowski's frog (Rana dybowskii) was used to test this hypothesis. We measured body mass (Mb)and hindlimb length (Lh) of 2-year old farmed frogs and wild frogs aged 2 to 5 years. Dybowski's frog demonstrated significant dimorphism in Mb and Lh. Mb was significantly greater among farmed 2-year old frogs in both sexes (p=0.000), while only among females w as Lh significantly greater for wild frogs (p=0.000). Lh/Mb was used as an index for origin discrimination to eliminate the influence of Mb due to variation of husbandry conditions among farms. Mean Lh/Mb for fanned frogs was significantly lower than for wild frogs (p=0.000) in the 2-year old age class.Discrimination correctly classified 84.4% of fanned and 96.3% of wild male frogs. Among females, 92.9% of farmed frogs and 90.1% wild frogs were correctly classified. The ovcrall correctness of classification was 92.1% and 90.8% for males and females, respectively. However, Lh/Mb revealed variation with age, resulting in reduced discriminative power for frogs ≥3 years old. We introduced a coefficient Ce to adjust the Lh/Mb of frogs ≥3 years to the level equivalent to 2-year frogs. Thc adjustment achieved 89.5% for overall correctness of origin for wild males and 92.4% for wild females ≥3 years old. These results show that Lh/Mb is an effective index to discriminate wild from fanned Dybowski's frog. Since the physical demands ofjumping are common among anurans, this index is also potentially applicable to other anuran species.

  4. Respiratory activity in the facial nucleus in an in vitro brainstem of tadpole, Rana catesbeiana.

    Science.gov (United States)

    Liao G-S; Kubin, L; Galante, R J; Fishman, A P; Pack, A I

    1996-04-15

    1. In studies of the central neural control of breathing, little advantage has been taken of comparative approaches. We have developed an in vitro brainstem preparation using larval Rana catesbeiana which generates two rhythmic neural activities characteristic of lung and gill ventilation. Based on the pattern of the facial (VII) nerve activity both lung and gill rhythm-related respiratory cycles were divided into three distinct phases. The purpose of this study was to characterize and classify membrane potential trajectories of respiratory motoneurons in the VII nucleus at intermediate stages (XII-XVII) of development. 2. Seventy-five respiratory-modulated neurons were recorded intracellularly within the facial motor nucleus region. Their resting membrane potential was between -40 and -80 mV. Sixty of them were identified as VII motoneurons and fifteen were non-antidromically activated. Membrane potentials of fifty-six of the seventy-five neurons were modulated with both lung (5-27 mV) and gill rhythms (3-15 mV) and the remaining nineteen neurons had only a modulation with lung rhythmicity (6-23 mV). No cells with gill modulation alone were observed. 3. All of the cells modulated with lung rhythmicity had only phase-bound depolarizing or hyperpolarizing membrane potential swings which could be categorized into four distinct patterns. In contrast, of the fifty-six cells modulated with gill rhythmicity, thirty-two were phasically depolarized during distinct phases of the gill cycle (four patterns were distinguished), whereas the remaining twenty-four were phase spanning with two distinct patterns. The magnitudes of lung and gill modulations were proportionally related to each other in the cells modulated with both rhythms. 4. In all sixteen neurons studied, a reduction or a reversal of phasic inhibitory inputs during a portion of the lung or gill respiratory cycle was observed following a negative current or chloride ion (Cl-) injection. The phasic membrane

  5. RNase activity of sialic acid-binding lectin from bullfrog eggs drives antitumor effect via the activation of p38 MAPK to caspase-3/7 signaling pathway in human breast cancer cells

    OpenAIRE

    Kariya, Yukiko; Tatsuta, Takeo; Sugawara, Shigeki; Kariya, Yoshinobu; Nitta, Kazuo; Hosono, Masahiro

    2016-01-01

    Sialic acid-binding lectin obtained from bullfrog eggs (SBL) induces cell death in cancer cells but not in normal cells. This antitumor effect is mediated through its ribo-nuclease (RNase) activity. However, the underlying molecular mechanisms remain unclear. We found that the p38 mitogen-activated protein kinase (MAPK) signaling pathway was activated when SBL induced cell death in three human breast cancer cell lines: SK-BR-3, MCF-7, and MDA-MB231. The suppression of p38 MAPK phosphorylation...

  6. Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in the Pacific Northwest

    Science.gov (United States)

    Pearl, C.A.; Bull, E.L.; Green, D.E.; Bowerman, J.; Adams, M.J.; Hyatt, A.; Wente, W.H.

    2007-01-01

    Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and we found ??? 1 detection of B. dendrobatidis from 43% of sites. Four of seven species tested positive for B. dendrobatidis, including the Northern Red-Legged Frog (Rana aurora), Columbia Spotted Frog (Rana luteiventris), and Oregon Spotted Frog (Rana pretiosa). We also detected B. dendrobatidis in nonnative American Bullfrogs (Rana catesbeiana) from six sites in western and central Oregon. Our study and other recently published findings suggest that B. dendrobatidis has few geographic and host taxa limitations among North American anurans. Further research on virulence, transmissibility, persistence, and interactions with other stressors is needed to assess the potential impact of B. dendrobatidis on Pacific Northwestern amphibians. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  7. An FCCP-sensitive Ca2+ store in bullfrog sympathetic neurons and its participation in stimulus-evoked changes in [Ca2+]i.

    Science.gov (United States)

    Friel, D D; Tsien, R W

    1994-07-01

    This study describes a Ca2+ store in fura-2-loaded bullfrog sympathetic neurons that modulates [Ca2+]i responses elicited by either depolarization or Ca2+ release from a caffeine- and ryanodine-sensitive store. This store is insensitive to caffeine and ryanodine, but is sensitive to the protonophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). The FCCP-sensitive store slows both the rise in [Ca2+]i during stimulation (apparently by accumulating Ca2+ from the cytosol) and the recovery following stimulation (by releasing the accumulated Ca2+ into the cytosol). For a fixed level of depolarization, recovery is slowed to an extent that depends on stimulus duration. [Ca2+]i imaging shows that these effects are prominent in the soma but not in growth cones. Ca2+ uptake by the FCCP-sensitive store appears to be strongly [Ca2+]i dependent, since it becomes influential only when [Ca2+]i approaches approximately 500 nM. Therefore, this store may specifically influence [Ca2+]i during moderate and strong stimulation. The effect of the store on responses to depolarization can be accounted for by a simple three-compartment scheme consisting of the extracellular medium, the cytosol, and a single internal store with a [Ca2+]i-dependent uptake mechanism resembling the mitochondrial Ca2+ uniporter. The store's effect on responses to caffeine-induced Ca2+ release can be accounted for by including a second internal compartment to represent the caffeine-sensitive store. While the identity of the FCCP-sensitive store is unknown, its sensitivity to FCCP is consistent with a mitochondrial pool. It is suggested that by modulating the temporal properties of [Ca2+]i following stimulation, the FCCP-sensitive store may influence the degree of activation of intracellular [Ca2+]i-dependent processes.

  8. 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.

  9. The precarious persistence of the endangered Sierra Madre yellow-legged frog Rana muscosa in southern California, USA

    Science.gov (United States)

    Backlin, Adam R.; Hitchcock, Cynthia J.; Gallegos, Elizabeth A.; Yee, Julie L.; Fisher, Robert N.

    2015-01-01

    We conducted surveys for the Endangered Sierra Madre yellow-legged frog Rana muscosa throughout southern California to evaluate the current distribution and status of the species. Surveys were conducted during 2000–2009 at 150 unique streams and lakes within the San Gabriel, San Bernardino, San Jacinto, and Palomar mountains of southern California. Only nine small, geographically isolated populations were detected across the four mountain ranges, and all tested positive for the amphibian chytrid fungus Batrachochytrium dendrobatidis. Our data show that when R. muscosa is known to be present it is easily detectable (89%) in a single visit during the frog's active season. We estimate that only 166 adult frogs remained in the wild in 2009. Our research indicates that R. muscosa populations in southern California are threatened by natural and stochastic events and may become extirpated in the near future unless there is some intervention to save them.

  10. 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.

  11. Rana iberica (Boulenger, 1879 goes underground: subterranean habitat usage and new insights on natural history

    Directory of Open Access Journals (Sweden)

    Gonçalo Rosa

    2013-04-01

    Full Text Available Reports of amphibians exploiting subterranean habitats are common, with salamanders being the most frequent and studied inhabitants. Anurans can occasionally be observed in caves and other subterranean habitats, but in contrast to salamanders, breeding had never been reported in a cave or similar subterranean habitat in Western Europe. Based on observations during visits to a drainage gallery in Serra da Estrela, Portugal, from May 2010 to December 2012, here we document: (i first report of Rana iberica reproduction in cave-like habitat, representing the fourth report of an anuran for the Palearctic ecozone; (ii oophagic habits of the tadpoles of R. iberica; and (iii Salamandra salamandra predation on R. iberica larvae. These observations, particularly of R. iberica, highlight our lack of knowledge of subterranean ecosystems in the Iberian Peninsula.

  12. Prevalence of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, in an endangered population of northern leopard frogs, Rana pipiens

    Directory of Open Access Journals (Sweden)

    Govindarajulu Purnima

    2010-03-01

    Full Text Available Abstract Background Emerging infectious diseases threaten naïve host populations with extinction. Chytridiomycosis, an emerging infectious disease of amphibians, is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd and has been linked to global declines in amphibians. Results We monitored the prevalence of Bd for four years in the Northern leopard frog, Rana pipiens, which is critically imperiled in British Columbia (BC, Canada. The prevalence of Bd initially increased and then remained constant over the last three years of the study. Young of the year emerging from breeding ponds in summer were rarely infected with Bd. Some individuals cleared their Bd infections and the return rate between infected and uninfected individuals was not significantly different. Conclusions The BC population of R. pipiens appears to have evolved a level of resistance that allows it to co-exist with Bd. However, this small population of R. pipiens remains vulnerable to extinction.

  13. The development of the region between the preexisting and nasecent membranes during the first cleavage of Rana amurensis eggs

    Institute of Scientific and Technical Information of China (English)

    GAOQIRONG; KONGHUAZHANG; 等

    1992-01-01

    The region between the preexisting and nascent membranes of a cleaving Rana egg is a dense protrusion region of nearly 40μm wide at 180° stage.Later,this region differentiate,into an upper part,a strip with long,branched and randomly distributed protrusions which are derived largely from the preexisting membrane and a lower part,a band with microvilli.During 4-and 8-cell stages,the strip is almost vanished and microvilli in the band is shortened.The nascent membrane is smooth at the 180° stage,then a rough area appears below the smooth region and quickly expands,wheat germ agglutini which can bind to preexisting membrane interrupts the development of the region between the preexisting and nascent membranes Detergent,Brij,having the property to increase the area of nascent membrane,does not interupt the development of the region between the preexisting and nascent membranes.

  14. Study on Manual Ova Hatching of Rana chinensis%中国林蛙卵人工孵化试验

    Institute of Scientific and Technical Information of China (English)

    于立忠; 孔祥文; 周永斌; 殷有

    2001-01-01

    his paper deals with the manual ova hatching of Rana chinensis.It is eviden that there are three different periods in the ova eclosion. The first period is at 75~80℃of effective water cumulative temperature. The peak period is at 100~120℃. The end is at 120~140℃. The most suitabale temperature of ova eclosion is 11~13℃. In this case, the eclosion speed is 1.6~2.2, and incubation period is 9~12 days,with the rate of eclosion over 80%. Manual hatching can increase the eclosion speed of ova. It is 10%~60% higher than CK, and also 25%~100% higher than the outdoor.

  15. The quantitative genetic basis of adaptive divergence in the moor frog (Rana arvalis) and its implications for gene flow.

    Science.gov (United States)

    Hangartner, S; Laurila, A; Räsänen, K

    2012-08-01

    Knowledge on the relative contribution of direct genetic, maternal and environmental effects to adaptive divergence is important for understanding the drivers of biological diversification. The moor frog (Rana arvalis) shows adaptive divergence in embryonic and larval fitness traits along an acidification gradient in south-western Sweden. To understand the quantitative genetic basis of this divergence, we performed reciprocal crosses between three divergent population pairs and reared embryos and larvae at acid and neutral pH in the laboratory. Divergence in embryonic acid tolerance (survival) was mainly determined by maternal effects, whereas the relative contributions of maternal, additive and nonadditive genetic effects in larval life-history traits differed between traits, population pairs and rearing environments. These results emphasize the need to investigate the quantitative genetic basis of adaptive divergence in multiple populations and traits, as well as different environments. We discuss the implications of our findings for maintenance of local adaptation in the context of migrant and hybrid fitness.

  16. Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae

    Directory of Open Access Journals (Sweden)

    Javier Hernández-Guzmán

    2011-03-01

    Full Text Available La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundamentó en el análisis de 131 dispersiones cromosómicas en estadio meiótico de dos adultos de la especie (una hembra y un macho. El análisis de las metafases, permitió establecer el número modal haploide de 1n=12 cromosomas bivalentes. La fórmula cromosómica del cariotipo haploide, se integró por 12 cromosomas birrámeos caracterizado por 12 pares de cromosomas bivalentes metacéntricos-submetacéntricos (msm. Los conteos en meiosis, hacen suponer como número diploide de cromosomas a un complemento integrado por 2n=24 cromosomas birrámeos. No fue posible observar presencia de cromosomas sexuales, entre las dispersiones meióticas del espécimen hembra y macho. Los resultados sugieren que la estructura cromosómica de S. baudinii, es compartida ampliamente entre las especies de la familia Hylidae y los cromosomas "B" son estructuras importantes en la diversificación de las especies.

  17. New species of Haematoloechus (Digenea: Plagiorchidae in the lung of the foothill yellow-legged frog Rana boylii (Anura, from Humboldt County, California, USA Especie nueva de Haematoloechus (Digenea: Plagiorchidae del pulmón de la rana de patas amarillas Rana boylii (Anura, de Humboldt County, California, Estados Unidos de América

    Directory of Open Access Journals (Sweden)

    David Zamparo

    2011-06-01

    Full Text Available A new species of Haematoloechus is described from the lungs of Rana boylii from Humboldt County, California. The new species is similar to Haematoloechus buttensis, Haematoloechus kernensis, and Haematoloechus complexus in general course of the uterus and gonad shape. It is similar to H. buttensis by having a cirrus sac terminating midway between the posterior margin of the pharynx and the anterior margin of the ovary, and having a smaller oral/ventral sucker ratio; to H. complexus by having the genital pore ventral to the pharynx, and it is similar to H. kernensis by having a larger oral sucker to pharynx width ratio. The new species is unique by lacking an extra-cecal longitudinal uterine loop from the hind-body. Molecularly, the new species differs 1.04-1.15% in partial 28S sequence with respect to H. complexus, and a monophyletic grouping of these specimens in a phylogenetic analysis of all available sequence data consistent with the species-specific status proposed herein. Evidence is also presented to suggest that specimens identified as H. buttensis in Rana pretiosa from British Columbia, Canada represents a new, but still undescribed species. The importance of conducting biological inventories of helminths, along with continued monitoring of populations, and collections based taxonomy are related.Una especie nueva de Haematoloechus es descrita de los pulmones de Rana boylii de Humboldt County, California. La especie nueva guarda semejanza con Haematoloechus buttensis, Haematoloechus kernensis, y Haematoloechus complexus en la disposición general del útero y en la forma de las gónadas. Es similar a H. buttensis en que la bolsa del cirro finaliza entre el margen posterior de la faringe y el margen anterior del ovario, y en presentar una relación menor entre la ventosa oral y el acetábulo; a H. complexus por tener el poro genital ventral a la faringe, y a H. kernensis por tener una relación mayor del ancho de la ventosa oral contra la

  18. 哈士蟆卵油化学成分研究%Study on the Chemical Constituents of the Ovum Oil of Rana temporaria chensinensis David.

    Institute of Scientific and Technical Information of China (English)

    卢立明; 宋少江; 徐绥绪; 徐峰

    2001-01-01

    @@ 哈士蟆油(oviductus ranae)为中国林蛙(Rana temporaria chensinensis David.)雌蛙的干燥输卵管制品,系一种名贵中药材,对它的化学成分和药效作用研究已有综述报道[1].但中国林蛙卵,民间用其治疗肺虚咳嗽,其化学成分至今未见报道.为开发利用这一资源,本文以林蛙卵为原料,对其脂溶性部分的化学成分进行了初步研究.

  19. Tectónica y procesos metalogénicos de la zona Tamajón-Campillo de Rana. Sistema Central

    Directory of Open Access Journals (Sweden)

    Vindel, E.

    1987-04-01

    Full Text Available The mineralogical, textural and structural features of Tamajon-Campillo de Ranas ore deposit, are studied in relation to the main silver district, (Hiendelanencina zone. The sulphides and sulphosalts have got similar chemical composition in both mineralizations and the deposition took place into the same geotectonic setting.En este trabajo se analizan las características mineralógicas. texturales y estructurales de la mineralización de Tamajón-Campillo de Ranas y su relación con el yacimiento argentífero principal (Zona de Hiendelaencina. Se establece una correlación paragenética de los sulfuros y sulfosales de ámbas zonas y se plantea una formación conjunta. dentro de un mismo encuadre geotectónico.

  20. Spatial Amphibian Impact Assessment – a management tool for assessment of road effects on regional populations of Moor frogs (Rana arvalis)

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt; Nachman, Gøsta Støger

    2013-01-01

    An expanding network of roads and railways fragments natural habitat affecting the amount and quality of habitat and reducing connectivity between habitat patches with severe consequences for biodiversity and population persistence. To ensure an ecologically sustainable transportation system it i...... demonstrate how SAIA can be used to assess which management measures would be best to mitigate the effect of landscape fragmentation caused by road constructions by means of a case study dedicated to the Moor frog (Rana arvalis)....

  1. 广西两栖类一新记录--镇海林蛙%A new record of amphibian species in Guangxi --Rana zhenhaiensis

    Institute of Scientific and Technical Information of China (English)

    周放; 蒋爱伍; 陆舟

    2005-01-01

    2001年在广西元宝山自然保护区进行动物资源考察时,采到一号蛙类标本,经鉴定为镇海林蛙(Rana zhenhaiensis),是广西两栖类无尾目新记录.标本现保存于广西大学动物科学技术学院标本室.

  2. Origin of centrifugal fibers to the labyrinth in the frog (Rana esculenta). A study with the fluorescent retrograde neuronal tracer 'Fast blue'.

    Science.gov (United States)

    Strutz, J; Spatz, W B; Schmidt, C L; Stürmer, C

    1981-06-29

    After injecting a solution of a fluorescent retrograde neuronal tracer (Fast blue, Diamidino compound 253/50) into the perilymphatic space of the frog labyrinth (Rana esculenta), labeled cells were found in the ventral and dorsal nuclei of the VIIIth nerve and in the nucleus reticularis medius. We consider these labeled cells to be the origin of the efferent innervation of the frog labyrinth. No evidence was found for the existence of a direct cerebello-labyrinthine connection.

  3. The New Technology of the Rana spinosa David Artificial Propagation and Cultivation%棘胸蛙人工繁育新技术

    Institute of Scientific and Technical Information of China (English)

    郑宝成

    2011-01-01

    在模拟棘胸蛙的野生态环境情况下,通过人工控制养殖池水的水温和酸碱度,根据棘胸蛙的生活特性,合理进行亲蛙选育、蝌蚪培育、幼蛙饲养和病害防治的技术改良,可以达到棘胸蛙年产卵次数达6~7次,年产卵量达1935粒,蛙卵孵化率达96.1%,蝌蚪变态率达96.5%,幼蛙成活率达96.8%的养殖效果。%We simulate the environment of the wild Rana Spinosa David,so that we can control temperature,basicity and acidity of the water.According to the living characteristic of Rana Spinosa David,we choose the parents of froggy,bring tadpole and little froggy up,make prevention of disease in improving technology rationally,the Rana Spinosa David can spawn 6~7 times with 1935 spawns every year,the frog incubation rate can reach as high as 96.1%,the tadpole metamorphosis rate 96.5%,the young frog survival rate 96.8%.

  4. Antipredator Behavioral Responses of Native and Exotic Tadpoles to Novel Predator

    Institute of Scientific and Technical Information of China (English)

    Fang ZHANG; Juan ZHAO; Yujie ZHANG; Kevin MESSENGER; Yong WANG

    2015-01-01

    Factors related to the invasion process, such as high abundance of invaders, residence time, and functional distinctiveness, are well documented, but less attention has been given to the effects of antipredator strategy of invasive species during colonization. In this study, we explored the antipredator strategy of an introduced species by comparing the predator avoidance behaviors of two native anuran species and one introduced (“exotic”) species in the presence of different predators. The two native anuran species used in the study were Black-spotted Pond FrogRana nigromaculata and Terrestrial Frog Rana limnocharis. The introduced (invasive) species used was American bullfrogLithobates catesbeianus. Chinese pond turtleChinemys reevesii, Red-backed rat snakeElaphe rufodorsata, and Big-headed turtle Platysternon megacephalum were used as predator species. Chinese pond turtles and Red-backed rat snakes are native predators of Black-spotted Pond Frogs and Terrestrial Frogs, while Big-headed turtles are novel (“unfamiliar”) to the two frogs. All three predator species are novel (“unfamiliar”) to the American bullfrog. The results show that tadpoles of the two native species displayed behaviors of recognizing the two native predators, but did not display the capability of identifying the novel predator. Results from our study also suggest that American bullfrog tadpoles exhibited strong antipredator behavioral responses by displaying the capability of identifying “unfamiliar” predators without cohabitation history and prior exposure to them. Such antipredator behavioral responses could have resulted in more favorable outcomes for an invading species during the invasive introductory process.

  5. Predation by Asian bullfrog tadpoles, Hoplobatrachus tigerinus, against the dengue vector, Aedes aegypti, in an aquatic environment treated with mosquitocidal nanoparticles.

    Science.gov (United States)

    Murugan, Kadarkarai; Priyanka, Vishwanathan; Dinesh, Devakumar; Madhiyazhagan, Pari; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Suresh, Udaiyan; Chandramohan, Balamurugan; Roni, Mathath; Nicoletti, Marcello; Alarfaj, Abdullah A; Higuchi, Akon; Munusamy, Murugan A; Khater, Hanem F; Messing, Russell H; Benelli, Giovanni

    2015-10-01

    Aedes aegypti is a primary vector of dengue and chikungunya. The use of synthetic insecticides to control Aedes populations often leads to high operational costs and adverse non-target effects. Botanical extracts have been proposed for rapid extracellular synthesis of mosquitocidal nanoparticles, but their impact against predators of mosquito larvae has not been well studied. We propose a single-step method for the biosynthesis of silver nanoparticles (AgNP) using the extract of Artemisia vulgaris leaves as a reducing and stabilizing agent. AgNP were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). SEM and XRD showed that AgNP were polydispersed, crystalline, irregularly shaped, with a mean size of 30-70 nm. EDX confirmed the presence of elemental silver. FTIR highlighted that the functional groups from plant metabolites capped AgNP, stabilizing them over time. We investigated the mosquitocidal properties of A. vulgaris leaf extract and green-synthesized AgNP against larvae and pupae of Ae. aegypti. We also evaluated the predatory efficiency of Asian bullfrog tadpoles, Hoplobatrachus tigerinus, against larvae of Ae. aegypti, under laboratory conditions and in an aquatic environment treated with ultra-low doses of AgNP. AgNP were highly toxic to Ae. aegypti larval instars (I-IV) and pupae, with LC50 ranging from 4.4 (I) to 13.1 ppm (pupae). In the lab, the mean number of prey consumed per tadpole per day was 29.0 (I), 26.0 (II), 21.4 (III), and 16.7 (IV). After treatment with AgNP, the mean number of mosquito prey per tadpole per day increased to 34.2 (I), 32.4 (II), 27.4 (III), and 22.6 (IV). Overall, this study highlights the importance of a synergistic approach based on biocontrol agents and botanical nano-insecticides for mosquito control.

  6. Desempenho e atividades enzimáticas em girinos de rã-touro Performance and enzymatic activities of the bullfrog tadpoles

    Directory of Open Access Journals (Sweden)

    José Teixeira de Seixas Filho

    2008-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho e as atividades das enzimas digestivas de girinos de rã-touro, alimentados com ração comercial durante 60 dias, com um girino por litro, em caixas com 30 L de água. Os parâmetros medidos quinzenalmente foram: sobrevivência, comprimento, peso final, consumo de ração, e a atividade de amilase, lipase e tripsina. O maior crescimento dos girinos foi do 15º ao 45º dia - 20,61 mm. Durante os primeiros 15 dias, os girinos apresentaram a maior taxa de crescimento específico, 16,73% por dia. Do 45º ao 60º dia, os girinos apresentaram o maior ganho de peso, 3,98±0,73 g, o maior consumo de ração, 14,40±1,14 g, e a melhor conversão alimentar, 3,67:1,0±0,18. Houve aumento significativo da atividade enzimática depois do 30º dia. Observaram-se relações entre as atividades específicas das enzimas e os distintos estágios de desenvolvimento dos girinos.The objective of this study was to evaluate the performance and the digestive enzyme activity in bullfrog tadpoles, fed with commercial ration during 60 days, at the density of one tadpole per liter in 30 L boxes. The parameters measured fortnightly were: survival, length, weight, ration consumption, and amylase, lipase and trypsin activities. There larger growth of the tadpoles occurred from the 15th to the 45th day - 20.61 mm. During the first 15 days, the tadpoles had the largest specific growth rate, 16.7% per day. From the 45th to the 60th day, the tadpoles had the largest weight gain, 3.98±0.73 g, the largest ration consumption, 14.40±1.14 g and the best feed conversion, 3.67:1.0±0.18. There was significant increase in enzyme activities after the 30th day. Relationships were observed between the specific enzyme activities and the different development phases of the tadpoles.

  7. Rana catesbeiana, pólvora e modulação supramolecular cicatrização intestinal e prognóstico no câncer de cólon: uma mesma origem biológica para o insucesso? Rana catesbeiana, Gunpowder and Supramolecular Modulation Intestinal Healing and Prognosis in Colon Cancer: The Same Biological Origin of the Failure?

    Directory of Open Access Journals (Sweden)

    Edna Delabio-Ferraz

    2010-06-01

    studying tadpole resorption of the American bullfrog. Metalloproteinases activity in cancer research, has taken a special place. Currently, evidences points to the cancer cell ability to interfere with enzymatic activity modulation - an co-factor which affects local invasiveness and metastatic dissemination. Both MMPs-2 and -7 have been frequently observed in colon cancer. Moreover, MMP-12 seems to counteract MMP-7 effect therefore considered as a protector and associated with better prognosis, in contrast to MMP-3, which may be responsible for a worse outcome. Association between high activity of MMPs, the prognosis of cancer and increased risk of intestinal anastomotic leakage has been highlighted, suggesting a consistent trilogy. Pharmacological therapy using MMPs inhibitors has been extensively studied, especially targeted for cancer control. The article discusses the most relevant information and updated information on the subject.

  8. Evaluation of Nutritional Components in the Muscle of Rana chensinensis%中国林蛙腿肉的营养成分分析与评价

    Institute of Scientific and Technical Information of China (English)

    王彬彬; 张文革; 夏艳洁

    2012-01-01

    按照国家食品相关标准分析的测定方法,对雌雄中国林蛙长白山亚种(简称中国林蛙)的腿部肌肉营养成分进行了比较分析和营养品质评价。结果表明:雌性与雄性中国林蛙肌肉(鲜样)的一般营养成分含量差异不显著(P〉0.05),分别为水分79.20%和79.60%、粗蛋白18.70%和18.10%、粗脂肪0.30%和0.60%、灰分1.10%和1.10%;雌雄蛙肉中17种氨基酸总量(干样)分别为88.71%和88.79%,其中7种必需氨基酸总量分别是38.47%和37.74%,鲜味氨基酸总量为30.27%和30.83%,雌雄中国林蛙必需氨基酸、鲜味氨基酸与氨基酸总量的比值均无显著差异(P〉0.05);必需氨基酸指数为雌蛙(87.10),略高于雄蛙(86.04)。根据氨基酸评分,中国林蛙的第一限制性氨基酸为缬氨酸,第二限制性氨基酸为苏氨酸;而根据化学评分,则第一限制性氨基酸为蛋氨酸+胱氨酸,第二限制性氨基酸为缬氨酸。研究表明,雌性与雄性中国林蛙腿肌的一般营养成分和氨基酸的含量与组成均无显著性差异,肌肉中粗蛋白和水分含量高,氨基酸组成和含量丰富,营养价值高,有较好的食用价值与保健作用。%The nutritional component in the muscle of male and female Rana chensinensis Weiet Chen(Rana chensinensis) was investigated,and the nutritional quality of the Rana chensinensis was analyzed and evaluated.The results showed that the content of moisture,crude ash,crude protein and ether extract in fresh muscle of male and female Rana chensinensis were 79.2% and 76.6%,1.10% and 1.10%,18.7% and 18.1%,0.30% and 0.60% respectively.There were no significant variations between the above data for the male and female Rana chensinensis(P0.05).Seventeen kinds of amino acids were found in the muscle of Rana chensinensis including 7 kinds of essential amino acids.In dry sample,the total content of amino acids(TAA)of male and female Rana chensinensis were 88.71% and

  9. Archaeological Survey at Fort Hood, Texas. Fiscal Year 1990: The Northeastern Perimeter Area

    Science.gov (United States)

    1994-01-01

    Pseudacris cark/O Cricket frog (Acris crepltans) Bullfrog (Rana catesbeana) Plains leopard frog (Rana bk~rO Rio Grande leopard frog (Rana berkladlero...an important chronological marker for historic sites at Fort Hood. 15. Carnival glass (1905-1935): an Iridescent pressed tableware given away at... carnivals during the early part of the century (Florence 1977). 16. Depression glass (1930-1940): a pressed glass tableware usually occurring In pale pink

  10. Pre-hibernation energy reserves in a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

    Science.gov (United States)

    Lu, X.; Li, B.; Li, Y.; Ma, X.; Fellers, G.M.

    2008-01-01

    Temperate anurans have energy substrates in the liver, fat bodies, carcass and gonads; these stores provide support for metabolism and egg production during hibernation, and for breeding activities in spring. This paper compares the energy budget shortly before hibernation among Rana chensinensis populations at elevations of 1400, 1700 and 2000 m along a river in northern China. The larger frogs, regardless of elevation, had relatively heavy storage organs and the masses of nearly all these organs were positively correlated with each other. After controlling for the effect of body size, we found no significant difference in energetic organ mass among different age classes for each of the three populations. There were sexual differences in energy strategy. Males in all populations accumulated greater reserves in liver, fat bodies and carcass than did females. In contrast, females put more energy into their ovaries and oviducts. Frogs from higher elevations tended to have heavier organs than those from lower elevations; however, the pattern did not vary systematically along fine environmental gradients. Mid-elevation R. chensinensis built up significantly more reserves than low-elevation individuals, but were similar to their highland conspecifics. Males from higher elevations tended to have heavier liver and fat bodies; females were similar in liver and ovary mass across all elevations, but formed heavier fat bodies, oviducts and somatic tissue at higher elevation sites.

  11. Subtle effects of environmental stress observed in the early life stages of the Common frog, Rana temporaria

    Science.gov (United States)

    Strong, Rebecca; Martin, Francis L.; Jones, Kevin C.; Shore, Richard F.; Halsall, Crispin J.

    2017-01-01

    Worldwide amphibian populations are declining due to habitat loss, disease and pollution. Vulnerability to environmental contaminants such as pesticides will be dependent on the species, the sensitivity of the ontogenic life stage and hence the timing of exposure and the exposure pathway. Herein we investigated the biochemical tissue ‘fingerprint’ in spawn and early-stage tadpoles of the Common frog, Rana temporaria, using attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy with the objective of observing differences in the biochemical constituents of the respective amphibian tissues due to varying water quality in urban and agricultural ponds. Our results demonstrate that levels of stress (marked by biochemical constituents such as glycogen that are involved in compensatory metabolic mechanisms) can be observed in tadpoles present in the pond most impacted by pollution (nutrients and pesticides), but large annual variability masked any inter-site differences in the frog spawn. ATR-FTIR spectroscopy is capable of detecting differences in tadpoles that are present in selected ponds with different levels of environmental perturbation and thus serves as a rapid and cost effective tool in assessing stress-related effects of pollution in a vulnerable class of organism. PMID:28317844

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

    Science.gov (United States)

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

    2014-10-01

    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.

  13. DDTs in rice frogs (Rana limnocharis) from an agricultural site, South China: tissue distribution, biomagnification, and potential toxic effects assessment.

    Science.gov (United States)

    Wu, Jiang-Ping; Zhang, Ying; Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian

    2012-04-01

    Contamination with agricultural pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), is among several proposed stressors contributing to the global declines in amphibian populations and species biodiversity. These chemicals were examined in insects and in the muscle, liver, and eggs of rice frogs (Rana limnocharis) from the paddy fields of an agricultural site in South China. The ΣDDT (sum of DDT, DDE, and DDD) concentrations ranged from 154 to 915, 195 to 1,400, and 165 to 1,930 ng/g lipid weight in the muscle, liver, and eggs, respectively. All the DDTs (DDT, DDE, and DDD) showed higher affinity for the liver relative to muscle tissue and can be maternally transferred to eggs in female frogs. The average biomagnification factors for DDTs ranged from 1.6 to 1.9 and 1.5 to 2.9 in female and male frogs, respectively, providing clear evidence of their biomagnification from insects to frogs. Compared with the reported DDT levels demonstrated to have toxic effects on frogs, DDTs in the present frogs are unlikely to constitute an immediate health risk. However, the adverse impacts of high DDT residues in eggs on the hatching success and their potential toxicity to the newly metamorphosed larval frogs should be assessed further.

  14. Characterization of the Skin Microbiota in Italian Stream Frogs (Rana italica) Infected and Uninfected by a Cutaneous Parasitic Disease.

    Science.gov (United States)

    Federici, Ermanno; Rossi, Roberta; Fidati, Laura; Paracucchi, Romina; Scargetta, Silvia; Montalbani, Elena; Franzetti, Andrea; La Porta, Gianandrea; Fagotti, Anna; Simonceli, Francesca; Cenci, Giovanni; Di Rosa, Ines

    2015-01-01

    In human and wildlife populations, the natural microbiota plays an important role in health maintenance and the prevention of emerging infectious diseases. In amphibians, infectious diseases have been closely associated with population decline and extinction worldwide. Skin symbiont communities have been suggested as one of the factors driving the different susceptibilities of amphibians to diseases. The activity of the skin microbiota of amphibians against fungal pathogens, such as Batrachochytrium dendrobatidis, has been examined extensively, whereas its protective role towards the cutaneous infectious diseases caused by Amphibiocystidium parasites has not yet been elucidated in detail. In the present study, we investigated, for the first time, the cutaneous microbiota of the Italian stream frog (Rana italica) and characterized the microbial assemblages of frogs uninfected and infected by Amphibiocystidium using the Illumina next-generation sequencing of 16S rRNA gene fragments. A total of 629 different OTUs belonging to 16 different phyla were detected. Bacterial populations shared by all individuals represented only one fifth of all OTUs and were dominated by a small number of OTUs. Statistical analyses based on Bray-Curtis distances showed that uninfected and infected specimens had distinct cutaneous bacterial community structures. Phylotypes belonging to the genera Janthinobacterium, Pseudomonas, and Flavobacterium were more abundant, and sometimes almost exclusively present, in uninfected than in infected specimens. These bacterial populations, known to exhibit antifungal activity in amphibians, may also play a role in protection against cutaneous infectious diseases caused by Amphibiocystidium parasites.

  15. Status of the California Red-legged Frog (Rana draytonii) in the State of Baja California, México

    Science.gov (United States)

    Peralta-Garcia, Anny; Hellingsworth, Bradford D.; Richmond, Jonathan Q.; Valdez-Villavicencio, Jorge H.; Ruiz-Campos, Gorgonio; Fisher, Robert N.; Cruz-Hernandez, Pedro; Galina-Tessaro, Patricia

    2016-01-01

    The California Red-legged Frog (Rana draytonii) is a threatened species in the United States that has undergone population declines, especially in southern California. Due to the lack of information on the status of Mexican populations, we surveyed for the presence of R. draytonii in Baja California and assessed possible threats to population persistence. Our study area extended from the U.S.-Mexican border to the southern end of the distribution of the species in the Sierra San Pedro Mártir. We found R. draytonii at six of 15 historical sites, none at five proxy sites (i.e., alternative sites chosen because the historical record lacked precise locality data), and four at 24 additional sites. The 10 occupied sites are within three watersheds in the Sierra San Pedro Mártir (two sites at Arroyo San Rafael, two sites at Arroyo San Telmo, and six sites at Arroyo Santo Domingo). We did not detect R. draytonii at 60% of historical sites, including the highest elevation site at La Encantada and multiple low-elevation coastal drainages, suggesting the species has declined in Baja California. The threats we noted most frequently were presence of exotic aquatic animal species, water diversion, and cattle grazing. Management of remaining populations and local education is needed to prevent further declines.

  16. Conservation genetics of evolutionary lineages of the endangered mountain yellow-legged frog, Rana muscosa (Amphibia: Ranidae), in southern California

    Science.gov (United States)

    Schoville, Sean D.; Tustall, Tate S.; Vredenburg, Vance T.; Backlin, Adam R.; Gallegos, Elizabeth; Wood, Dustin A.; Fisher, Robert N.

    2011-01-01

    Severe population declines led to the listing of southern California Rana muscosa (Ranidae) as endangered in 2002. Nine small populations inhabit watersheds in three isolated mountain ranges, the San Gabriel, San Bernardino and San Jacinto. One population from the Dark Canyon tributary in the San Jacinto Mountains has been used to establish a captive breeding population at the San Diego Zoo Institute for Conservation Research. Because these populations may still be declining, it is critical to gather information on how genetic variation is structured in these populations and what historical inter-population connectivity existed between populations. Additionally, it is not clear whether these populations are rapidly losing genetic diversity due to population bottlenecks. Using mitochondrial and microsatellite data, we examine patterns of genetic variation in southern California and one of the last remaining populations of R. muscosa in the southern Sierra Nevada. We find low levels of genetic variation within each population and evidence of genetic bottlenecks. Additionally, substantial population structure is evident, suggesting a high degree of historical isolation within and between mountain ranges. Based on estimates from a multi-population isolation with migration analysis, these populations diversified during glacial episodes of the Pleistocene, with little gene flow during population divergence. Our data demonstrate that unique evolutionary lineages of R. muscosa occupy each mountain range in southern California and should be managed separately. The captive breeding program at Dark Canyon is promising, although mitigating the loss of neutral genetic diversity relative to the natural population might require additional breeding frogs.

  17. Evolutionary dynamics of a rapidly receding southern range boundary in the threatened California red-legged frog (Rana draytonii)

    Science.gov (United States)

    Richmond, Jonathan Q.; Barr, Kelly R.; Backlin, Adam R.; Vandergast, Amy G.; Fisher, Robert N.

    2013-01-01

    Populations forming the edge of a species range are often imperiled by isolation and low genetic diversity, with proximity to human population centers being a major determinant of edge stability in modern landscapes. Since the 1960s, the California red-legged frog (Rana draytonii) has undergone extensive declines in heavily urbanized southern California, where the range edge has rapidly contracted northward while shifting its cardinal orientation to an east-west trending axis. We studied the genetic structure and diversity of these frontline populations, tested for signatures of contemporary disturbance, specifically fire, and attempted to disentangle these signals from demographic events extending deeper into the past. Consistent with the genetic expectations of the ‘abundant-center’ model, we found that diversity, admixture, and opportunity for random mating increases in populations sampled successively further away from the range boundary. Demographic simulations indicate that bottlenecks in peripheral isolates are associated with processes extending tens to a few hundred generations in the past, despite the demographic collapse of some due to recent fire-flood events. While the effects of recent disturbance have left little genetic imprint on these populations, they likely contribute to an extinction debt that will lead to continued range contraction unless management intervenes to stall or reverse the process.

  18. Toxic effects of octylphenol on the expression of genes in liver identified by suppression subtractive hybridization of Rana chensinensis.

    Science.gov (United States)

    Li, Xin-Yi; Xiao, Ning; Zhang, Yu-Hui

    2014-01-01

    Octylphenol (OP) is the degradative product of alkylphenol ethoxylates that are widely used to produce rubber, pesticides, and paints. It is chemically stable substance and demonstrates estrogenic effects, toxicity and carcinogenic effects in the environment. The toxin accumulates rapidly in the liver where it exerts most of its damage, but the molecular mechanisms behind its toxicity remain unclear. Due to limited information concerning the effect of OP on liver, this study investigates how OP causes hepatotoxicity in liver. Here, suppression subtractive hybridization was used to identify the alterations in gene transcription of the frog (Rana chensinensis) after exposure to OP. After hybridization and cloning, the subtractive cDNA libraries were obtained. At random, 207 positive clones were selected and sequenced from the subtractive libraries, which gave a total of 75 gene fragment sequences. The screening identified numerous genes involved in apoptosis, signal transduction, cytoskeletal remodeling, innate immunity, material and energy metabolism, translation and transcription which were extensively discussed. Two sequenced genes were analyzed further using real time quantitative PCR. The two genes from the library were found to be transcriptionally up-regulated. These results confirmed the successful construction of the subtractive cDNA library that was enriched for the genes that were differentially transcribed in the amphibian liver challenged with OP, and for the first time present the basic data on toxicity effect of OP on liver.

  19. Flavor improvement of Rana spinosa enzymatic hydrolysate%石蛙的酶解液化及风味改良

    Institute of Scientific and Technical Information of China (English)

    王瑞君

    2012-01-01

    Rana spinosa meat was hydrolyzed by papain and neutral protease. Lactic acid bacteria and rice wine yeasts were used to improve the flavor of the hydrolysate. Results indicate that neutral protease is superior to papain. The amount of amino nitrogen included in fermentation broth fermented by lactic acid bacteria is higher. The fermenting liquor from lactic acid bacteria flavor is better than that from rice wine yeast.%在酶适宜的环境条件下,利用木瓜蛋白酶与中性蛋白酶酶解石蛙肉及利用乳酸菌、黄酒酵母对酶解液进行风味改良。结果表明,中性蛋白酶对石蛙的水解效果较好,乳酸菌发酵液中氨态氮含量较高,乳酸菌发酵液风味改良效果优于黄酒酵母。

  20. Geographical variation and sexual differences of body length and age composition in Rana temporaria: the ontogenetic development and phenotypic trends

    Directory of Open Access Journals (Sweden)

    Lyapkov Sergey

    2012-06-01

    Full Text Available The analysis of literature data on the mean values of age and body length of adult individuals of widespread species Rana temporaria from about 70 spatially separated populations, including our published data, was conducted. The evident trend in population mean age increase with the decrease of the of activity season length was revealed as well as the absence of that trend in the mean body length, with the maximal mean value in body length being near central part of the range. Our explanation of non-linear trend in the mean values of body length does not contradict other models of geographic variability explaining the correspondence and discrepance with the Bergman rule. In addition our explanation corresponds to the revealed features of interpopulation variation in growth rate. The revealed trend of variation in the mean body length is resulted from both growth rate decrease and mean age increase with the decrease in the length of activity season. The relatively low mean values of body length in populations from south and southern-west borders of the range are explained not only by low mean age but by lower growth rate despite high length of activity season. The interpopulation variation in body length is determined not only by body length but by age composition differences both between and within population. Therefore, the direction and intensity of sexual differences have not distinct trends, and the correspondence to Rensch rule (in contrast to Bergman rule is rarely observed.

  1. Calcium paradox induces apoptosis in the isolated perfused Rana ridibunda heart: involvement of p38-MAPK and calpain.

    Science.gov (United States)

    Aggeli, Ioanna-Katerina; Zacharias, Triantafyllos; Papapavlou, Georgia; Gaitanaki, Catherine; Beis, Isidoros

    2013-12-01

    "Calcium paradox" as a term describes the deleterious effects conferred to a heart perfused with a calcium-free solution followed by repletion, including loss of mechanical activity and sarcomere disruption. Given that the signaling mechanisms triggered by calcium paradox remain elusive, in the present study, we tried to investigate them in the isolated perfused heart from Rana ridibunda. Calcium paradox was found to markedly activate members of the MAPKs (p43-ERK, JNKs, p38-MAPK). In addition to lactate dehydrogenase (LDH) release in the perfusate (indicative of necrosis), we also confirmed the occurrence of apoptosis by using the TUNEL assay and identifying poly(ADP-ribose) polymerase (PARP) fragmentation and upregulated Bax expression. Furthermore, using MDL28170 (a selective calpain inhibitor), a role for this protease was revealed. In addition, various divalent cations were shown to exert a protective effect against the calcium paradox. Interestingly, SB203580, a p38-MAPK inhibitor, alleviated calcium-paradox-conferred apoptosis. This result indicates that p38-MAPK plays a pro-apoptotic role, contributing to the resulting myocardial dysfunction and cell death. To our knowledge, this is the first time that the calcium paradox has been shown to induce apoptosis in amphibians, with p38-MAPK and calpain playing significant roles.

  2. 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. PMID:24278410

  3. Local adaptation with high gene flow: temperature parameters drive adaptation to altitude in the common frog (Rana temporaria).

    Science.gov (United States)

    Muir, A P; Biek, R; Thomas, R; Mable, B K

    2014-02-01

    Both environmental and genetic influences can result in phenotypic variation. Quantifying the relative contributions of local adaptation and phenotypic plasticity to phenotypes is key to understanding the effect of environmental variation on populations. Identifying the selective pressures that drive divergence is an important, but often lacking, next step. High gene flow between high- and low-altitude common frog (Rana temporaria) breeding sites has previously been demonstrated in Scotland. The aim of this study was to assess whether local adaptation occurs in the face of high gene flow and to identify potential environmental selection pressures that drive adaptation. Phenotypic variation in larval traits was quantified in R. temporaria from paired high- and low-altitude sites using three common temperature treatments. Local adaptation was assessed using Q(ST)-F(ST) analyses, and quantitative phenotypic divergence was related to environmental parameters using Mantel tests. Although evidence of local adaptation was found for all traits measured, only variation in larval period and growth rate was consistent with adaptation to altitude. Moreover, this was only evident in the three mountains with the highest high-altitude sites. This variation was correlated with mean summer and winter temperatures, suggesting that temperature parameters are potentially strong selective pressures maintaining local adaptation, despite high gene flow.

  4. 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.

  5. High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family.

    Science.gov (United States)

    Brelsford, A; Rodrigues, N; Perrin, N

    2016-01-01

    Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

  6. Distribution of adrenomedullin and proadrenomedullin N-terminal 20 peptide immunoreactivity in the pituitary gland of the frog Rana perezi.

    Science.gov (United States)

    Collantes, M; Bodegas, M E; Sesma, M P; Villaro, A C

    2003-08-01

    Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are two multifunctional peptides processed from a common precursor which have been described in numerous mammalian organs, including the pituitary gland. Previous studies have found AM immunoreactivity in neurohypophysis nerve fibers of amphibian pituitary. In the present study, immunocytochemical and Western blot analysis in the pituitary gland of the amphibian Rana perezi demonstrated in the adenohypophysis both AM and PAMP. AM-like immunoreactivity was found in a moderate number of endocrine cells of the pars distalis. In the neurohypophysis, AM was observed not only in nerve fibers of pars nervosa and axonal projections innervating the pars intermedia, but also in the outer zone of the median eminence. PAMP staining was observed in numerous endocrine cells scattered all over the pars distalis and in some cells of the pars tuberalis, but not in the neurohypophysis. In order to compare the quantity of AM and PAMP immunoreactivity between pars distalis of female and male specimens, an image analysis study was done. Significant differences for AM immunoreactivity (p<0.001) between sexes was found, the males showing higher immunostained area percentage. Differences of PAMP immunoreactivity were not significant (p=0.599). Western blot analysis detected bands presumably corresponding to precursor and/or intermediate species in the propeptide processing.

  7. Relationship between epithelial and connective tissues in the stomach of the frog Rana temporaria during metamorphosis: an ultrastructural study.

    Science.gov (United States)

    Villaro, A C; Rovira, J; Bodegas, M E; Burrell, M A; Sesma, P

    1998-08-01

    In the course of metamorphosis of the stomach of Rana temporaria tadpoles there is a marked increase in the amount of active mesenchymal fibroblasts and extracellular matrix underlying the regenerating gastric epithelium. At the onset of metamorphosis, a thick PAS-positive basement membrane is developed around the epithelial component of the mucosa, formed by the apical, degenerating larval epithelium and the basal, regenerative epithelial cords. Under the electron microscope, a folded basement membrane is usually revealed under the apical degenerating epithelium while a compact basement membrane (up to 1-2 microns thick), forming both patches and more extensive areas, is frequently seen around the regenerative glandular cords. Cytoplasmic processes, extending from both the epithelial and mesenchymal fibroblastic cells, cross the basement membrane and make physical contact between the two cellular types. At mid-metamorphosis areas of thick PAS-positive basement membrane are still observed around the differentiating glandular outlines, before disappearing completely at late metamorphosis. The probable involvement of intertissue interactions between epithelium and connective elements in the morphogenesis, proliferation and differentiation of secondary, definitive frog stomach is discussed. Early contacts between epithelium and phagocytes, probably related to the invasion of epithelium by the phagocytic cells, have also been observed.

  8. 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.

  9. Effect of exposure to continuous light and melatonin on ovarian follicular kinetics in the skipper frog, Rana cyanophlyctis.

    Science.gov (United States)

    Udaykumar, K; Joshi, B N

    1997-01-01

    Ovarian follicular kinetics and gravimetric changes in the ovary and oviducts were studied in the skipper frog, Rana cyanophlyctis, following exposure to continuous light and melatonin treatment during the breeding season. Daily late-afternoon injections of melatonin (15 micrograms subcutaneous) for 30 days decreased the gonadosomatic index (GSI), whereas continuously available melatonin from subcutaneous implants did not influence the GSI compared to those of controls. Exposure to continuous light for 30 days stimulated the GSI, and melatonin given as daily injections prevented the continuous-light induced increase in GSI. Oviductal weights decreased only in the melatonin-injected groups. Data on follicular kinetics revealed a decrease in first-growth-phase (FGP) oocytes and an increase in medium-sized second-growth-phase (MSGP) and large-sized second-growth-phase (LSGP) oocytes following continuous-light exposure. Melatonin administered to continuous-light-exposed frogs did not change the FGP oocyte number; however, it reduced both the MSGP and LSGP oocytes. Melatonin administration to frogs held in a light and dark cycle increased FGP oocytes and decreased MSGP and LSGP oocytes. Atretic follicles increased in all melatonin-treated groups. The results suggest that continuous light stimulates and melatonin inhibits reproductive function in this species.

  10. Variation of growth rate and survival in embryos and larvae of Rana temporaria populations from the Pyrenees

    Directory of Open Access Journals (Sweden)

    Neus Oromi

    2015-12-01

    Full Text Available Variations on embryonic and larval life history traits of ectotherm organisms are strongly affected by temperature conditions. However, these effects can vary between species and populations depending on the mechanisms that act in a determinate local habitat. In the present study, we analysed the effects of temperature on several embryonic and larval traits (survival, development and growth rate until the metamorphosis of Rana temporaria in two populations living at different altitude (1540 and 2100 m in the Pyrenees. Five spawns from each population were distributed in a common garden experiment at different temperature treatments according to the normal temperature range that tadpoles might experience in the field and also considering a high treatment (24 °C to test a possible effect of global warming. Like in other studies of the same species in a latitudinal gradient, the temperature effects depended on the analysed trait. Our results support the general rule that the rate of development is faster at higher temperatures, although survival was significantly affected by the highest temperature in the highland population. Size varied at embryonic and larval stages and was largest at metamorphosis in the highland population. In concordance, the growth rate was higher in the highland population suggesting a countergradient variation in response to the short growing season. However, this possible adaptation can be altered in a global warming scenario with an increase of mortality and limited growth.

  11. Predator mediated selection and the impact of developmental stage on viability in wood frog tadpoles (Rana sylvatica

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    Calsbeek Ryan

    2011-12-01

    Full Text Available Abstract Background Complex life histories require adaptation of a single organism for multiple ecological niches. Transitions between life stages, however, may expose individuals to an increased risk of mortality, as the process of metamorphosis typically includes developmental stages that function relatively poorly in both the pre- and post-metamorphic habitat. We studied predator-mediated selection on tadpoles of the wood frog, Rana sylvatica, to identify this hypothesized period of differential predation risk and estimate its ontogenetic onset. We reared tadpoles in replicated mesocosms in the presence of the larval odonate Anax junius, a known tadpole predator. Results The probability of tadpole survival increased with increasing age and size, but declined steeply at the point in development where hind limbs began to erupt from the body wall. Selection gradient analyses indicate that natural selection favored tadpoles with short, deep tail fins. Tadpoles resorb their tails as they progress toward metamorphosis, which may have led to the observed decrease in survivorship. Path models revealed that selection acted directly on tail morphology, rather than through its indirect influence on swimming performance. Conclusions This is consistent with the hypothesis that tail morphology influences predation rates by reducing the probability a predator strikes the head or body.

  12. Prolonged relaxation after stimulation of the clasping muscle of male frog, Rana japonica, during the breeding season.

    Science.gov (United States)

    Ishii, Yoshiki; Tsuchiya, Teizo

    2010-07-01

    We investigated the mechanical properties of the flexor carpi radialis muscle (FCR), a forelimb muscle used mainly for amplexus in the breeding season (February to March), of the male Japanese brown frog, Rana japonica. In the present experiment, the changes in force and stiffness of the FCR before, during, and after contraction were measured at 4 degrees C. The total time from the end of stimulation to the end of relaxation was about 30 min. The time course of this prolonged relaxation was fitted by two exponential decay processes. Stiffness decreased during prolonged relaxation, but stayed higher than force, when normalized to peak values. These mechanical properties of the FCR were different from those of the glutaeus magnus muscle (GM) in the hindlimb, used for jumping. When a quick release was applied to the FCR during relaxation, the force recovered gradually after a sudden decrease. The time course of this force recovery was fitted by a single exponential term, and the rate constant decreased as the prolonged relaxation proceeded. The possible involvement of active process(es) in the prolonged relaxation is discussed.

  13. Disease associated with integumentary and cloacal parasites in tadpoles of northern red-legged frog Rana aurora aurora.

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    Nieto, Nathan C; Camann, Michael A; Foley, Janet E; Reiss, John O

    2007-10-31

    A total of 6830 northern red-legged frog Rana aurora aurora tadpoles were examined under a dissecting microscope for oral disc, integumentary, and cloacal abnormalities in 13 ponds in and near Redwood National Park in northern California. Of these, 163 tadpoles were collected for histopathological investigation, including 115 randomly collected individuals, 38 collected with oral disc abnormalities, and 10 collected due to severe morbidity of unknown etiology. The tadpoles were infected with 8 parasites, including Batrachochytrium dendrobatidis (the amphibian chytrid), trematodes, leeches, and protozoa. Chytridiomycosis was detected at an overall prevalence of 6.4%, but prevalence was higher in tadpoles with oral disc lesions than in those with normal oral discs (43.5% versus 6.1%). Interestingly, infection was associated with some environmental and co-infection risk factors. Individual tadpoles possessed 0 to 5 species of parasites in varying intensities. Apiosoma sp. was the most prevalent (66%) and widespread. Tadpoles infected with B. dendrobatidis had a lower diversity of oral parasites than those uninfected. During the field portion of the study, a large number (approximately 500) of moribund and dead tadpoles was seen occurring at multiple locations within and surrounding Redwood National Park. Ten animals were collected for histological examination and a diverse protozoal infection was discovered, including some known pathogens of fish. This study is the first reporting parasitism and disease in natural populations of northern red-legged frogs.

  14. Nueva especie de rana del género Pristimantis del grupo lacrimosus (Amphibia: Craugastoridae del Parque Nacional Sangay, Ecuador

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    Diego Batallas R.

    2014-01-01

    Full Text Available Describimos una nueva especie de rana terrestre del genero Pristimantis de tamaño mediano (LRC en machos desde 22.18 a 25.13 mm descubierta en los bosques nublados de las estribaciones orientales del Parque Nacional Sangay, al centro oriente de Ecuador, a elevaciones de 2750 m. Asignamos a Pristimantis latericius sp. nov., al grupo Pristimantis lacrimosus, el cual se diferencia del resto de miembros de este grupo por presentar tubérculos prominentes en el parpado superior y una coloración rojo anaranjado en el dorso. Las llamadas son cortas, conformadas por una sola nota y dos bandas armónicas. Importantes levantamientos de información faunística se han venido generando en los últimos años en el Parque Nacional Sangay, sin embargo es necesario incrementar estudios que ayuden a documentar la ecología e historia natural de los anfibios, ya que sin lugar a dudas ayudaran a comprender procesos ecológicos. El descubrimiento de esta y otras nuevas especies en este sector, demuestra su importancia biológica confortando al desarrollo de planes de conservación en este importante Patrimonio Natural de la Humanidad.

  15. The quality and fertility of sperm collected from European common frog (Rana temporaria) carcasses refrigerated for up to 7 days.

    Science.gov (United States)

    Shishova, Natalia V; Uteshev, Viktor K; Sirota, Nikolai P; Kuznetsova, Elena A; Kaurova, Svetlana A; Browne, Robert K; Gakhova, Edith N

    2013-01-01

    There is a catastrophic decrease in the biodiversity of amphibians coupled with the loss of genetic variation. The perpetuation of amphibian biodiversity demands a multifaceted approach, including the use of reproduction technologies (RTs), to enable efficient reproduction in captivity and to prevent the loss of genetic variation. Reproduction technologies for the storage of amphibian sperm for days to weeks, when refrigerated at 4°C, or for millennia when cryopreserved have recently undergone rapid development. Sperm from amphibians may be obtained through excision and maceration of testes; however, this is sometimes not possible with rare or endangered species. Alternate methods of obtaining sperm are through hormonal induction, or as spermatozoa from the carcasses of recently dead amphibians. The use of sperm from carcasses of recently dead amphibians is particularly valuable when sampled from genetically important founders in conservation breeding programs, or where catastrophic mortality is occurring in natural population. Sperm harvested over a period of 7 days from the testes of European common frog (Rana temporaria) carcasses stored in a refrigerator were assessed for percentage and progressive motility, cell membrane integrity, nuclear DNA fragmentation, and fertilizing ability. In addition, the survival of resulting embryos to hatch was recorded. Results indicated that some sperm of R. temporaria remain motile and fertile when harvested from frog carcasses refrigerated up to 7 days post-mortem, and resulting embryos can develop to hatch.

  16. Accumulation and pharmacokinetics of estrogenic chemicals in the pre- and post-hatch embryos of the frog Rana rugosa.

    Science.gov (United States)

    Takase, Minoru; Shinto, Hideaki; Takao, Yuji; Iguchi, Taisen

    2012-01-01

    Amphibian eggs spawned in water are exposed immediately to various chemicals present in their water. The present study aimed to investigate the accumulation and pharmacokinetics of 17α-ethynylestradiol (EE(2)), bisphenol A (BPA), and nonylphenol (NP), as well as 17β-estradiol (E(2)), in the pre-hatch and post-hatch embryos of the frog Rana rugosa. Fertilized eggs were exposed to chemicals at a final concentration of 500 nM in breeding water for two days, then the embryos with jelly coats were reared in fresh-breeding water without supplementation of the xenoestrogens for six more days. All exogenous chemicals were concentrated in the embryo body at two days after fertilization, whereas their concentrations in the jelly coat were the same as those in the breeding water. The bioconcentration factors for E(2), EE(2), BPA, and NP were 217.9, 170.2, 382.3, and 289.1, respectively, suggesting that the estrogenic chemicals were concentrated in the embryo body through the jelly coat.

  17. Toxic effects of 1-methyl-3-octylimidazolium bromide on the early embryonic development of the frog Rana nigromaculata.

    Science.gov (United States)

    Li, Xiao-Yu; Zhou, Jing; Yu, Miao; Wang, Jian-Ji; Pei, Yuan Chao

    2009-02-01

    Toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on the early embryonic development of the frog Rana nigromaculata were evaluated. Frog embryos in different developmental stages (early cleavage, early gastrula, or neural plate) were exposed to 0, 45, 63, or 88.2 mg/L of the ionic liquid [C8mim]Br for 96 h. The 96-h median lethal concentration values at the early cleavage, early gastrula, and neural plate stages of development were 85.1, 43.4, and 42.4 mg/L, respectively. In embryos exposed to [C8mim]Br, the duration of embryo dechorionation was prolonged in the early cleavage and neural plate, but not the early gastrula, stages of development compared with control embryos. Embryos in the neural plate developmental stage were found to have the highest mortality rate following [C8mim]Br exposure. These results suggest that [C8mim]Br has toxic effects on the early embryonic development of the frog.

  18. Changes in growth rate and macroelement and trace element accumulation in Hydrocharis morsus-ranae L. during the growing season in relation to environmental contamination.

    Science.gov (United States)

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra; Dambiec, Małgorzata

    2017-02-01

    The temporal variations in plant chemistry connected with its life cycle may affect the cycling of elements in an ecosystem as well as determine the usefulness of the species in phytoremediation and bioindication. In this context, there is a gap in knowledge on the role of floating plants for elements cycling in aquatic reservoirs. The aim of the study was to determine if there are variations in Hydrocharis morsus-ranae (European frog-bit) bioaccumulation capacity and the growth rate of its population during the growing season and to test the impact of environmental pollution on these features. The content of macroelements (Ca, K, Mg, N, Na, P, S) and trace metals (Cd, Co, Cu, Cr, Hg, Fe, Mn, Ni, Pb, Zn) was determined in H. morsus-ranae collected monthly from June to October from habitats differing in environmental contamination. The results showed that the highest content of most trace metals (Co, Cr, Cu, Hg, Mn, Ni, Zn) and some nutrients (N, P) in plants as well as the greatest bioaccumulation efficiency occurred simultaneously in the beginning of the growing season. In the following months, a dilution effect (manifested by a decrease in content) related to the rapid growth was observed. Co, Mn, and Ni content in plant tissues reflected the level of environmental contamination throughout the growing season which makes H. morsus-ranae a potential biomonitor of pollution for these metals. Considering the great bioaccumulation ability, high sensitivity to contamination, and low biomass of European frog-bit in polluted systems, further investigation is required to assess the real phytoremediation capability of the species.

  19. An immunocytochemical and ultrastructural study of the larval anterior intestine of the frog Rana temporaria, with especial reference to endocrine cells.

    Science.gov (United States)

    Bodegas, M E; Villaro, A C; Burrell, M A; Rovira, J; Valverde, E; Ortiz De Zárate, A; Sesma, P

    1997-10-01

    Endocrine cells of the larval intestine of Rana temporaria tadpoles have been identified by argyrophilic, immunocytochemical and electron-microscopical techniques. Scarce endocrine cells have been found in both the short non-absorptive zone immediately following the stomach, and in the rest of the anterior intestine. Endocrine cells are frequently seen to extend a cytoplasmic process towards the lumen. Immunoreactivity for serotonin, somatostatin, bombesin and cholecystokinin-8 has been detected. According to the ultrastructural traits of the endocrine granules, three larval intestinal endocrine populations have been differentiated.

  20. Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae

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    Javier Hernández-Guzmán

    2011-03-01

    Full Text Available La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundamentó en el análisis de 131 dispersiones cromosómicas en estadio meiótico de dos adultos de la especie (una hembra y un macho. El análisis de las metafases, permitió establecer el número modal haploide de 1n=12 cromosomas bivalentes. La fórmula cromosómica del cariotipo haploide, se integró por 12 cromosomas birrámeos caracterizado por 12 pares de cromosomas bivalentes metacéntricos-submetacéntricos (msm. Los conteos en meiosis, hacen suponer como número diploide de cromosomas a un complemento integrado por 2n=24 cromosomas birrámeos. No fue posible observar presencia de cromosomas sexuales, entre las dispersiones meióticas del espécimen hembra y macho. Los resultados sugieren que la estructura cromosómica de S. baudinii, es compartida ampliamente entre las especies de la familia Hylidae y los cromosomas "B" son estructuras importantes en la diversificación de las especies.Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae. The Mexican tree frog Smilisca baudinii, is a very common frog in Central America. In spite their importance to keep the ecological equilibrium of the rainforest, its biology and genetics are poorly known. In order to contribute with its biological knowledge, we described the typical meiotic karyotype based in standard cytogenetic protocols to specimens collected in Tabasco, Mexico. The study was centered in the analysis of 131 chromosome spreads at meiotic stage from two adults of the

  1. American ginseng

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    ... and inflammation of the lining of the stomach (gastritis). American ginseng is also used for low iron ... Anemia. Bleeding disorders. Digestive disorders. Dizziness. Fever. Fibromyalgia. Gastritis. Hangover symptoms. Headaches. HIV/AIDS. Impotence. Insomnia. Memory ...

  2. Temporal occurrence and community structure of helminth parasites in southern leopard frogs, Rana sphenocephala, from north central Oklahoma.

    Science.gov (United States)

    Vhora, M Suhail; Bolek, Matthew G

    2015-03-01

    Currently, little information is available about the temporal recruitment of helminth communities in amphibian hosts. We examined the helminth community structure and temporal recruitment of helminth parasites in southern leopard frogs, Rana sphenocephala. Specifically, we were interested in how host life history such as habitat, age and/or size, diet, sex, and temporal variation in abiotic factors (precipitation and temperature) were important in determining monthly infection patterns of helminth populations and communities in southern leopard frogs. From May to September 2011, 74 southern leopard frogs were collected from Teal Ridge in Stillwater Payne County, OK, USA. Sixty-nine (93 %) of 74 frogs were infected with 1 or more helminth species. During our collecting period, the average monthly temperature was lowest in May and highest in July, and monthly precipitation was highest in May and lowest during the first week of September. The component community consisted of 11 species of helminth, including 1 larval and 1 adult cestode, 2 larval and 3 adult trematodes, and 1 juvenile and 3 adult nematodes. Of the 1790 helminths recovered, 51 % (911) were nematodes, 47 % (842) were cestodes, and 2 % (37) were trematodes. There were significant differences in the total abundance and mean species richness of helminths acquired by skin contact or through frog diet in monthly component communities of southern leopard frogs. A positive correlation existed for percentage of all helminths acquired by skin contact and monthly precipitation (r = 0.94, P < 0.01). Conversely, a negative correlation existed for monthly precipitation and percentage of helminths acquired by diet (r = -0.94, P < 0.01). Our results indicate that abiotic conditions such as precipitation have a major influence on the avenues for and constraints on the transmission of helminths with life cycles associated with water/moisture or terrestrial intermediate/paratenic hosts and are important in structuring

  3. 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.

  4. Cryptic invasion of Northern Leopard Frogs (Rana pipiens) across phylogeographic boundaries and a dilemma for conservation of a declining amphibian

    Science.gov (United States)

    O'Donnell, Ryan P.; Drost, Charles A.; Mock, Karen E.

    2017-01-01

    Anthropogenic introduction of species is a major contributor to loss of biodiversity. Translocations within the range of a species are less frequently recognized, but have the potential for negative effects as well. Genetic mixing may lead to loss of local adaptations or further decline through outbreeding depression. These cryptic invasions may be quite difficult to recognize, but genetic tools can be used to recognize and monitor such intraspecific introductions. Conversely, translocations within species can be an important conservation tool to reduce inbreeding depression and replace lost genetic diversity. Thus, cryptic invasions can be either an aid or a hindrance to conservation efforts. We tested for the presence of non-native genotypes and assessed the extent and nature of introgression in populations of Northern Leopard Frog (Rana pipiens) in the southwestern US, where populations have declined to a few remnant populations. The most abundant and diverse complex of populations in the region contained a mitochondrial haplotype that was not native to the western US, probably resulting from the introduction of released pets, laboratory animals, or release during fish stocking. These non-native haplotypes were well integrated into a large complex of ponds and lakes, contributing to high genetic diversity in this area. Logistically, the geographic extent of non-native genetic influence within this population precludes eliminating or controlling the non-native component of this population. We recommend assessing the progress and fate of the introgression over time—along with population fitness parameters—to determine whether this introduction is beneficial or detrimental to population persistence. Meanwhile, translocations from nearby locations with similar environmental conditions have the best prospects for avoiding problems with outbreeding depression in other declining populations and will also most effectively preserve regional genetic diversity.

  5. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Victoria E.M. Gerber

    2016-03-01

    Full Text Available The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46, and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70, Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog.

  6. Histopathological changes and erythrocytic nuclear abnormalities in Iberian green frogs (Rana perezi Seoane) from a uranium mine pond

    Energy Technology Data Exchange (ETDEWEB)

    Marques, S.M. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)], E-mail: s.reis.marques@gmail.com; Antunes, S.C. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Pissarra, H. [Laboratorio de Anatomia Patologica, Centro de Investigacao Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinaria, U.T.L., Lisboa (Portugal); Pereira, M.L. [Departamento de Biologia/Centro de Investigacao em Materiais Ceramicos e Compositos (CICECO), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Goncalves, F.; Pereira, R. [Departamento de Biologia/Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2009-01-31

    In spite of their sensitivity to anthropogenic stressors, adults of Rana perezi Seoane were found inhabiting effluent ponds from a uranium mine. Due to the presence of such organisms in this environment, it becomes of paramount importance to assess the damages induced by local contamination on these aquatic vertebrates, in order to integrate this information on a site-specific risk assessment that is being carried out in the area. To attain this purpose an ethically and statistically acceptable number of green frogs were captured in the mine pond (M) and in a pristine river (VR), a few kilometres from the mine. Bioaccumulation of metals and histopathological alterations were evaluated in the liver, kidneys, spleen, lungs and testes of the animals. Simultaneously, blood samples were collected for the evaluation of genotoxic damage on erythrocytes. Animals captured in the M pond showed significantly increased levels of Be, Al, Mn, Fe and U in the liver, as well as Pb and U in the kidney. The liver was the main target organ for the bioaccumulation of Be, Al, Fe and U. However, renal histopathologies were more severe than those of liver. The main tissue alterations recorded in animals from the mine were: a slight increase in melanomacrophagic centers (MMC) in liver, lung and kidneys; dilatation of the renal tubules lumen associated with tubular necrosis. A significantly higher number of erythrocytic abnormalities (lobed, notched and kidney shaped nuclei and micronuclei) were recorded in frogs from M than in frogs from VR, along with a significantly lower frequency of immature erythrocytes. Both observations suggested that the removal of abnormal blood cells might be compromised.

  7. Features of the karyotypes of Pelophylax ridibundus Pallas, 1771 and Rana macrocnemis Boulenger, 1885 (Amphibia: Ranidae from Armenia

    Directory of Open Access Journals (Sweden)

    A Martirosyan

    2009-08-01

    Full Text Available Сhromosomal complements of Pelophylax ridibundus Pallas, 1771 from 9 localities (Northern, Central and South Armenia and Rana macrocnemis Boulenger, 1885 from one locality (North-West Armenia have been analyzed. The chromosome sets of P. ridibundus collected from 8 localities showed 2n=26, (10m+12sm+4st; NF=52. A secondary constriction has been observed in all studied individuals on the 10-th chromosome pair showing NOR-positive reaction. C-positive heterochromatin blocks have been observed on long arms of the 2-nd and 10-th pairs of chromosomes (7 localities. In addition, C-heterochromatin blocks have been found on interstitial regions of short arms of the 12-th pairs, as well as in telomeric regions of long arms of the 9-th pairs and on short arms of the 5-th pair in the frogs from 2 localities. The karyotype of P. ridibundus from populations near Ejmiatsin differs from other populations (2n=26, 12m+10sm+4st. Diploid number of chromosomes of R. macrocnemis was also 26 (8m+12sm+6st, NF=52. Blocks of C-positive heterochromatin have been revealed in telomeric parts of the 1-st, 2-nd (p, 3-rd (q, 4-th (q, 6-th, 9-th (p, 10-th (p,q and 13-th (q pairs, as well as in interstitial regions of the 1-st and 2-nd pairs of chromosomes.  Intrapopulation and interpopulation geographic variations of karyotypes and C-heterochromatin banding patterns of P. ridibundus have been revealed. Karyotypically, morphotypes “macrocnemis” and “camerani” are closely related.

  8. 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.

  9. Exposure to heptachlor: evaluation of the effects on the larval and adult epidermis of Rana kl. esculenta.

    Science.gov (United States)

    Fenoglio, Carla; Grosso, Amelia; Boncompagni, Eleonora; Gandini, Carlo; Milanesi, Gloria; Barni, Sergio

    2009-01-31

    Widely used in the past against termites and soil insects, the chlorinated insecticide heptachlor (H) is a toxic contaminant which represents a risk for both terrestrial and aquatic organisms. Like many organochlorine pesticides, heptachlor and heptachlor epoxide (HE), with oxidation products synthesized by many plant and animal species, degrade slowly since many of the derived compounds are persistent. This increases the status of heptachlor as a hazardous pollutant. In the present experimental study we exposed specimens of Rana kl. esculenta, from the tadpole stage through to their complete metamorphosis, to three different concentrations of heptachlor (4, 40 and 400 ppb). Mortality and HE bioaccumulation were evaluated on all the experimental groups. Since amphibian integument directly interacts with the environmental constituents (water, air and soil), we investigated the toxic effects on the ventral epidermis of both tadpole and adult samples by employing such histo-cytopathological biomarkers as ultrastructural morphology, certain enzyme activities (acid and alkaline phosphatases, AcPase, and AlkPase; succinic dehydrogenase, SDH; alpha-naphtyl butyrate esterase, ANBE; nitric oxide synthase/NADPH diaphorase, NOS/NADPHd). Also, the levels of reactive oxygen species (ROS) in the different conditions were evaluated. The results obtained were of ecological relevance, in particular as regards the effects of this environmental toxicant on the samples of tadpole epidermis. Severe morphological alterations were observed in the larval epidermal cells (apical and skein cells), whereas the cell epidermis (keratinocytes and mitochondria-rich cells) of the adult survivors showed changes in enzyme activities, particularly those involved in the protective response to xenobiotic injury. In general, morpho-histochemical studies, analysis of HE bioaccumulation and mortality showed a relation to the H doses employed.

  10. Mechanistic basis of adaptive maternal effects: egg jelly water balance mediates embryonic adaptation to acidity in Rana arvalis.

    Science.gov (United States)

    Shu, Longfei; Suter, Marc J-F; Laurila, Anssi; Räsänen, Katja

    2015-11-01

    Environmental stress, such as acidification, can challenge persistence of natural populations and act as a powerful evolutionary force at ecological time scales. The ecological and evolutionary responses of natural populations to environmental stress at early life-stages are often mediated via maternal effects. During early life-stages, maternal effects commonly arise from egg coats (the extracellular structures surrounding the embryo), but the role of egg coats has rarely been studied in the context of adaptation to environmental stress. Previous studies on the moor frog Rana arvalis found that the egg coat mediated adaptive divergence along an acidification gradient in embryonic acid stress tolerance. However, the exact mechanisms underlying these adaptive maternal effects remain unknown. Here, we investigated the role of water balance and charge state (zeta potential) of egg jelly coats in embryonic adaptation to acid stress in three populations of R. arvalis. We found that acidic pH causes severe water loss in the egg jelly coat, but that jelly coats from an acid-adapted population retained more water than jelly coats from populations not adapted to acidity. Moreover, embryonic acid tolerance (survival at pH 4.0) correlated with both water loss and charge state of the jelly, indicating that negatively charged glycans influence jelly water balance and contribute to embryonic adaptation to acidity. These results indicate that egg coats can harbor extensive intra-specific variation, probably facilitated in part via strong selection on water balance and glycosylation status of egg jelly coats. These findings shed light on the molecular mechanisms of environmental stress tolerance and adaptive maternal effects.

  11. The influence of water quality on the embryonic survivorship of the Oregon spotted frog (Rana pretiosa) in British Columbia, Canada.

    Science.gov (United States)

    McKibbin, René; Dushenko, William T; vanAggelen, Graham; Bishop, Christine A

    2008-05-20

    In Canada, the Oregon spotted frog (Rana pretiosa) is a critically endangered species with only three known populations and an estimated breeding population of less than 400 located in isolated sites in the extreme south-west corner of British Columbia. Floating Nitex cages were used to assess embryonic survivorship in two populations of Oregon spotted frogs from 2002-2005. One population, near Aldergrove, BC experienced declines in population size while the other population, at Maria Slough, increased during the period 1997-2001. During embryo development, we measured trace metals, nutrients and physical parameters in the water at each site. These were used to test the hypothesis that water quality parameters were correlated with embryonic survivorship. During the study period in the declining population at Aldergrove R. pretiosa bred at two distinct sub sites (A and B) located 500 m apart within the wetland. Mean embryonic survivorship varied from 9% to 36% at sub site A and from 78% to 88% at sub site B whereas in the population in Maria Slough, the mean embryonic survivorship varied from 77% to 84%. Sulphate was the only water chemistry variable that differed significantly between the two study sites and was the highest at Maria Slough. A weak significant positive correlation was found between chloride and embryonic survivorship and conductivity and embryonic survivorship. A multiple regression model found conductivity was the only significant variable. We concluded that natural water chemistry conditions of low chloride and consequently low conductivity may be contributing to low embryonic survivorship in the population of R. pretiosa at MD Aldergrove, BC.

  12. Preparation of collagen from the skin of Rana chensinensis%中国林蛙皮中胶原蛋白的提取研究

    Institute of Scientific and Technical Information of China (English)

    李琳琳; 鲍成伟; 杨翔华; 王战勇

    2012-01-01

    采用酶解法从中国林蛙皮中提取胶原蛋白。考查了提取次数、液料比、酶解时间、酶解温度以及酶用量对胶原蛋白提取率的影响。单因素考察结合正交试验设计得到胶原蛋白的优化提取条件为:提取次数为2次,液料比为60,提取时间为72 h,提取温度为37℃,酶用量为1.5%。此条件下中国林蛙皮胶原蛋白的产率可达26.2%。%The skins of Rana chensinensis were used to preparation of collagen. The experiment examines ratio of liquids to raw material, reaction time, reaction temperature and enzyme dosage on the extraction rate of collagen. Combining single factor study and orthogonal test, the optimal extraction conditions were chosen as follows: extraction number is 2, extraction time is 72 h, extraction temperature is 37 ℃ enzyme dosage is 1.5%, ratio of liquids to raw material is 60. Under these conditions, the yield of Rana chensinensis skin collagen is 26.2%.

  13. Influence of Ribeiroia ondatrae (Trematoda: Digenea) infection on limb development and survival of northern leopard frogs (Rana pipiens): effects of host stage and parasite-exposure level

    Science.gov (United States)

    Schotthoefer, Anna M.; Koehler, Anson V.; Meteyer, Carol U.; Cole, Rebecca A.

    2003-01-01

    Recent evidence suggests that infection by larvae of the trematode Ribeiroia ondatrae accounts for a significant proportion of limb malformations currently observed in amphibian populations of North America. However, the effects of R. ondatrae infection on northern leopard frogs (Rana pipiens), one of the species most frequently reported with malformations, have not been adequately explored. Moreover, the risk factors associated with R. ondatrae-induced malformations have not been clearly identified. We examined the effects of timing of infection on tadpole survival and limb development. Rana pipiens tadpoles were individually exposed to R. ondatrae cercariae at the pre-limb-bud (Gosner stages 24 and 25), limb-bud (Gosner stages 27 and 28), or paddle (Gosner stages 31–33) stages of development and monitored through metamorphosis. The effects of infection were stage-specific. Infections acquired at the pre-limb-bud stage resulted in a high mortality rate (47.5–97.5%), whereas tadpoles infected at the limb-bud stage displayed a high malformation rate (16% overall), and the magnitude of effects increased with the level of exposure to cercariae. In contrast, infections acquired at the paddle stage had no effect on limb development or tadpole survival, which suggests that the timing of R. ondatrae infection in relation to the stage structure of tadpole populations in the wild is an important determinant of the degree to which populations are affected by R. ondatrae.

  14. De kleine groene kikker in Buitenvaart. Beoordeling van de effecten van de aanleg van bedrijventerrein Buitenvaart 2 in de gemeente Hoogeveen op het duurzaam voortbestaan van de Kleine groene kikker (Rana lessonae) en mogelijkheden voor compensatie

    NARCIS (Netherlands)

    Blitterswijk, van H.; Stumpel, A.H.P.; Vliet, van C.J.M.

    2003-01-01

    Mede in het licht van de Flora- en faunawet worden de effecten beoordeeld van de geplande aanleg van een bedrijventerrein in de gemeente Hoogeveen op de populaties Kleine groene kikker (Rana lessonae). Tevens worden maatregelen genoemd ter compensatie en mitigatie van deze effecten.

  15. American Connections

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2015-01-01

    The Danish artist Thomas Bang spent his early years in the USA. The works he created in this formative period were thus profoundly shaped by the contemporary movements in American art of the 1960s and 1970s when sculpture, or to be more precise, three-dimensional work became a hotbed of expansive...... experiments. This article traces how Bang made a radical move from painting to sculpture, which was characteristic of that time, and how he developed his artistic idiom by taking an active part in some of the seminal new departures in American art, in particular process art and post-minimalism. By leaping...... to the lasting impact of Bang's American period, which remains the key to understanding his works....

  16. American Dream in Early American Literatuer

    Institute of Scientific and Technical Information of China (English)

    屈彩娥; 李小玺

    2008-01-01

    American dream has often been closely rehted to American literature.Many say that the American literary history can be seen as the history of American dreams.In most periods in history,writers,whose dreams have been infused in a variety of characters create the American literature.While in Early American literature,American dream had been presented in a dif-ferent way.

  17. 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.

  18. Trends in anuran occupancy from northeastern states of the North American Monitoring Program

    Science.gov (United States)

    Weir, Linda; Fiske, Ian J.; Royle, J. Andrew

    2009-01-01

    We present the first multi-year occupancy trends from North American Amphibian Monitoring Program (NAAMP) data in 10 northeastern states using seven years of data (2001-2007). NAAMP uses a calling survey technique where observers listen for anuran vocalizations along assigned random roadside routes. We were able to assess occupancy trends in 10 northeastern states for 16 species and one species complex, for 94 species/state combinations. We found no significant trends for 64 species/state combinations. For the remaining 30 species/state combinations with significant trends, these split between declining and increasing trends. On a species-by-species basis, two species had declining trends, with significant trends in six states for Pseudacris crucifer and four states for Bufo americanus. The trends of Rana catesbeiana significantly increased in four states, but had no trend in the remaining states.

  19. Frogs on the beach: Ecology of California Red-legged Frogs (Rana draytonii) in coastal dune drainages

    Science.gov (United States)

    Halstead, Brian J.; Kleeman, Patrick M.

    2017-01-01

    California Red-legged Frogs (Rana draytonii) are typically regarded as inhabitants of permanent ponds, marshes, and slow-moving streams, but their ecology in other habitats, such as drainages among coastal dunes, remains obscure. Because coastal dune ecosystems have been degraded by development, off-highway vehicle use, stabilization, and invasive species, these unique ecosystems are the focus of restoration efforts. To better understand the ecology of California Red-legged Frogs in coastal dune ecosystems and to avoid and minimize potential negative effects of dune restoration activities on these rare frogs, we studied their spatial ecology, habitat selection, and survival in coastal dune drainages at Point Reyes National Seashore, California, USA. All 22 radio-marked frogs remained in their home drainages throughout the spring and summer of 2015 and, with some notable exceptions, most remained close to water. Local convex hull home ranges of four out of five California Red-legged Frogs with > 20 observations in dunes were < 1,600 m2 . At the population level, frogs were 1.7 (95% credible interval, 1.2‒4.4) times more likely to select sites 1 m closer to water, and were 83 (2.0‒17,000) times more likely to select sites with 10% greater percentage cover of logs that served as refuges from environmental extremes and predators. On average, California Red-legged Frogs avoided the invasive plants Iceplant (Carpobrotus edulis) and European Beachgrass (Ammophila arenaria). Frogs were 0.68 (0.32‒0.89) and 0.55 (0.24‒0.75) times as likely to select areas that had 10% greater cover of these plants, respectively. Assuming constant risk of mortality, California Redlegged Frogs had an annual survival rate of 0.70 (0.27‒0.96) in coastal dune drainages. Our results indicate that coastal dune drainages provide a locally important habitat for California Red-legged Frogs. Restoration practices that maintain wetted drainages with logjams are likely to benefit California

  20. Alteration of the hypothalamic-pituitary-gonadal axis in estrogen- and androgen-treated adult male leopard frog, Rana pipiens

    Directory of Open Access Journals (Sweden)

    Jones Jeremy T

    2005-01-01

    Full Text Available Abstract Background Gonadal steroids, in particular 5 alpha-dihydrotestosterone (DHT and 17 beta-estradiol (E2, have been shown to feed back on the hypothalamic-pituitary-gonadal (HPG axis of the ranid frog. However, questions still remain on how DHT and E2 impact two of the less-studied components of the ranid HPG axis, the hypothalamus and the gonad, and if the feedback effects are consistently negative. Thus, the goal of the study was to examine the effects of DHT and E2 upon the HPG axis of the gonadally-intact, sexually mature male leopard frogs, Rana pipiens. Methods R. pipiens were implanted with silastic capsules containing either cholesterol (Ch, a control, DHT, or E2 for 10 or 30 days. At each time point, steroid-induced changes in hypothalamic GnRH and pituitary LH concentrations, circulating luteinizing hormone (LH, and testicular histology were examined. Results Frogs implanted with DHT or E2 for 10 days did not show significant alterations in the HPG axis. In contrast, frogs implanted with hormones for 30 days had significantly lower circulating LH (for both DHT and E2, decreased pituitary LH concentration (for E2 only, and disrupted spermatogenesis (for both DHT and E2. The disruption of spermatogenesis was qualitatively similar between DHT and E2, although the effects of E2 were consistently more potent. In both DHT and E2-treated animals, a marked loss of all pre-meiotic germ cells was observed, although the loss of secondary spermatogonia appeared to be the primary cause of disrupted spermatogenesis. Unexpectedly, the presence of post-meiotic germ cells was either unaffected or enhanced by DHT or E2 treatment. Conclusions Overall, these results showed that both DHT and E2 inhibited circulating LH and disrupted spermatogenesis progressively in a time-dependent manner, with the longer duration of treatment producing the more pronounced effects. Further, the feedback effects exerted by both steroid hormones upon the HPG axis were

  1. Foraging behaviour in tadpoles of the bronze frog Rana temporalis: Experimental evidence for the ideal free distribution

    Indian Academy of Sciences (India)

    Dheeraj K Veeranagoudar; Bhagyashri A Shanbhag; Srinivas K Saidapur

    2004-06-01

    The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to assess the profitability of food habitats and distribute themselves accordingly was tested experimentally using a rectangular choice tank with a non-continuous input design. Food (boiled spinach) was placed at two opposite ends of the choice tank in a desired ratio (1 : 1, 1 : 2 or 1 : 4) to create habitat A and B. The tadpoles in Gosner stage 28–33, pre-starved for 24 h, were introduced in an open ended mesh cylinder placed in the center of the choice tank, held for 4 min (for acclimation) and then released to allow free movement and habitat selection. The number of tadpoles foraging at each habitat was recorded at 10, 15, 20, 25 and 30 min time intervals. The actual suitability, (the food available in a habitat after colonization of tadpoles) of each habitat was obtained from the equation = - () where is basic suitability (amount of food provided at each habitat before release of tadpoles), is the rate of depletion of food (lowering effect) with introduction of each tadpole, and is the density of tadpoles in habitat . The expected number of tadpoles at each habitat was derived from the actual suitability. With no food in the choice tank, movement of the tadpoles in the test arena was random indicating no bias towards any end of the choice tank or the procedure. In tests with a 1 : 1 food ratio, the observed ratio of tadpoles (11.71 : 12.28) was comparable with the expected 12 : 12 ratio. The observed number of tadpoles in the habitats with a 1 : 2 food ratio was 8.71 : 15.29 and 7.87 : 16.13 for pure and mixed parental lines respectively. In both cases, the observed ratios were close to the expected values (7 : 17). Likewise, in experiments with a 1 : 4 food ratio, the observed number of tadpoles in the two habitats (10.78 : 37.22) did not differ significantly from the expected ratio of 7 : 41. In all tests, the number of R. temporalis tadpoles matched ideally with

  2. Contextual and psychosocial factors predicting Ebola prevention behaviours using the RANAS approach to behaviour change in Guinea-Bissau.

    Science.gov (United States)

    Gamma, Anna E; Slekiene, Jurgita; von Medeazza, Gregor; Asplund, Fredrik; Cardoso, Placido; Mosler, Hans-Joachim

    2017-05-15

    The outbreak of the Ebola virus disease (EVD) in West Africa in December 2013 was the largest Ebola outbreak in history. This study aimed to measure the underlying contextual and psychosocial factors of intentions to perform Ebola prevention behaviours (not touching people who might be suffering from Ebola, reporting suspected cases to the National Ebola Hotline, NEH) in Guinea-Bissau. Geographical location, cross-border market activities, poor water, sanitation and hygiene (WASH) conditions, and burial practices in some communities pose a serious risk in terms of potential EVD outbreak and seriously hamper its prevention in Guinea-Bissau. In July and August 2015, quantitative data from 1369 respondents were gathered by structured face-to-face interviews. The questionnaire was based on the psychosocial factors of the RANAS (risks, attitudes, norms, abilities, and self-regulation) model. Data were analyzed by multiple linear regression analyses. The most important predictors for the intention to call the NEH were believing that calling the Hotline would help the infected person, perceiving that important members from the household approve of calling the Hotline, thinking that calling the Hotline is something they should do, and believing that it is important to call the Hotline to report a suspected case. For the intention not to touch someone who might be suffering from Ebola, the most important predictors were health knowledge, the perception of risk with regard to touching a person who might be suffering from Ebola, and the belief that they were able not to touch a possibly infected person. Age in years was the only significant contextual predictor for one of the two behavioural intentions, the intention to call the Hotline. It seems that younger people are more likely to use a service like the NEH than older people. Strengths and gaps were identified in the study population in relation to the intention to perform prevention behaviours. These call for innovative

  3. Amphibian population genetics in agricultural landscapes: does viniculture drive the population structuring of the European common frog (Rana temporaria?

    Directory of Open Access Journals (Sweden)

    Patrick P. Lenhardt

    2017-07-01

    Full Text Available Amphibian populations have been declining globally over the past decades. The intensification of agriculture, habitat loss, fragmentation of populations and toxic substances in the environment are considered as driving factors for this decline. Today, about 50% of the area of Germany is used for agriculture and is inhabited by a diverse variety of 20 amphibian species. Of these, 19 are exhibiting declining populations. Due to the protection status of native amphibian species, it is important to evaluate the effect of land use and associated stressors (such as road mortality and pesticide toxicity on the genetic population structure of amphibians in agricultural landscapes. We investigated the effects of viniculture on the genetic differentiation of European common frog (Rana temporaria populations in Southern Palatinate (Germany. We analyzed microsatellite data of ten loci from ten breeding pond populations located within viniculture landscape and in the adjacent forest block and compared these results with a previously developed landscape permeability model. We tested for significant correlation of genetic population differentiation and landscape elements, including land use as well as roads and their associated traffic intensity, to explain the genetic structure in the study area. Genetic differentiation among forest populations was significantly lower (median pairwise FST = 0.0041 at 5.39 km to 0.0159 at 9.40 km distance than between viniculture populations (median pairwise FST = 0.0215 at 2.34 km to 0.0987 at 2.39 km distance. Our analyses rejected isolation by distance based on roads and associated traffic intensity as the sole explanation of the genetic differentiation and suggest that the viniculture landscape has to be considered as a limiting barrier for R. temporaria migration, partially confirming the isolation of breeding ponds predicted by the landscape permeability model. Therefore, arable land may act as a sink habitat

  4. American Houses

    Institute of Scientific and Technical Information of China (English)

    张梦华

    2004-01-01

    American houses usually have private kitchens,a living room and sometimes separate areas for eating and watching television,A house usually has its own mailbox,a yard with plants or perhaps a lawn,and a place to store garbage out of sight.

  5. American Culture Reflected in American English

    Institute of Scientific and Technical Information of China (English)

    李华芳

    2013-01-01

    Language is a vehicle for culture. It is also a key component of culture. It not only reflects culture but also influences culture. As a variety of British English, American English, especially American words and expressions can reflect American culture from many aspects. This paper studies some typical traits of American culture reflected in words and expressions of American Eng-lish.

  6. American Connections

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2015-01-01

    The Danish artist Thomas Bang spent his early years in the USA. The works he created in this formative period were thus profoundly shaped by the contemporary movements in American art of the 1960s and 1970s when sculpture, or to be more precise, three-dimensional work became a hotbed of expansive...... experiments. This article traces how Bang made a radical move from painting to sculpture, which was characteristic of that time, and how he developed his artistic idiom by taking an active part in some of the seminal new departures in American art, in particular process art and post-minimalism. By leaping...... forward to Bang's later works produced after his return to Denmark, the article also demonstrates how the sculptural syntax and working principles developed in the early works still underlie and structure the artist's more allegorical sculptures and installations from the 2000s, thus testifying...

  7. Morfologia e enzimologia do sistema digestório dos girinos da rã-touro (Rana catesbeiana) durante o desenvolvimento e metamorfose

    OpenAIRE

    Bahia, Verônica Regina Lobato de Oliveira [UNESP

    2007-01-01

    A importância da fase de girino para a ranicultura reside no fato de que após a metamorfose existirão animais em condições compatíveis com os índices zootécnicos. Entretanto, a compreensão dos processos morfológicos e fisiológicos pelos quais os girinos passam durante o seu desenvolvimento e metamorfose ainda é limitada. Neste contexto, este estudo tem como objetivo descrever as mudanças morfológicas do sistema digestório e o perfil das enzimas digestivas dos girinos da rã touro (Rana catesbe...

  8. Diverse families of antimicrobial peptides isolated from skin secretions of three species of East Asian frogs, Babina daunchina, Babina adenopleura, and Rana omeimontis (Ranidae).

    Science.gov (United States)

    Hu, Yuhong; Xu, Shiqi; Hu, Yonghong; Guo, Chao; Meng, Hao; Li, Jing; Liu, Jingze; Wang, Hui

    2014-07-01

    Twenty-two novel cDNAs encoding 22 peptide precursors for 19 mature peptides including antimicrobial peptides (AMPs) were identified from East Asian frog species Babina daunchina, Babina adenopleura, and Rana omeimontis skin-derived cDNA libraries. Two atypical members of the brevinin-1 family AMPs, named brevinin-1AN1 (FLTGVLKLASKIPSVLCAVLKTC) and brevinin-1DN1(FLKGVINLASKIPSMLCAVLKTC), were purified from the skin secretions of B. adenopleura and B. daunchina, respectively. A member of the ranatuerin-2 family AMP named ranatuerin-2DN1 (GLFDSITQGLKDTAVKLLDKIKCKLSACPPA) was also purified from the skin secretion of B. daunchina. One AMP named japonicin-2OM1 (FIVPSIFLLKKAFCIALKKNC) was purified from the skin secretion of R. omeimontis. The antimicrobial tests showed that brevinin-1DN1, brevinin-1DN2, brevinin-1AN1, and japonicin-2OM1 possess higher antimicrobial activity against Gram-positive bacteria than Gram-negative bacteria.

  9. A de novo Assembly of the Common Frog (Rana temporaria Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Stephen J Price

    Full Text Available Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1 at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses, but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research.

  10. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3',4,4',5-pentachlorobiphenyl

    Science.gov (United States)

    Huang, Y.-W.; Melancon, M.J.; Jung, R.E.; Karasov, W.H.

    1998-01-01

    Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 in corn oil at a concentration of 0.2, 0.7, 2.3 and 7.8 mg/kg body weight or with corn oil alone. Appropriate assay conditions with hepatic microsomes were determined for four cytochrome P450-associated monooxygenases: ethoxyresorufin-O-dealkylase (EROD), methoxy-ROD (MROD), benzyloxy-ROD (BROD) and pentoxy-ROD (PROD). One week after PCB administration, the specific activities of EROD, MROD, BROD and PROD were not elevated at doses ? 0.7 mg/kg (p > 0.05), but were significantly increased at doses ? 2.3 mg/kg compared to the control groups (p frogs.

  11. Una nueva especie de rana terrestre del género Pristimantis (Amphibia: Craugastoridae, de la Cordillera de Kutukú, Ecuador

    Directory of Open Access Journals (Sweden)

    Jorge Brito M.

    2013-01-01

    Full Text Available Describimos una especie nueva de mediano tamaño (LRC en la hembra 38.7 mm; en machos de 23.8 a 26.4 mm de rana terrestre del género Pristimantis de los bosques sub-tropicales de la Cordillera de Kutukú, del sureste de Ecuador, a elevaciones de 1581-1820 m. Asignamos a Pristimantis almendariz sp. nov., al subgénero Hypodictyon, serie de especies ridens. La nueva especie difiere de otros miembros de la serie ridens por su patrón distintivo con manchas dorsales, membrana timpánica ausente, presencia de tubérculos cónicos agrandados en el párpado, tubérculo inter-orbital prominente, e iris plateado con reticulaciones negras.

  12. Immunofluorescence studies on gonadotropin releasing hormone (GRH) in the fore-brain and the neurohypophysis of the green frog, Rana esculenta L.

    Science.gov (United States)

    Goos, H J; Ligtenberg, P J; van Oordt, P G

    1976-05-13

    Using antibodies against mammalian LH-RH, the double antibody-immunofluorecence technique has been applied to serial cross sections of the brains of adult Rana esculenta. Immunoreactive material was found in perikarya of an unpaired nucleus in front of the preoptic recess. The axons of these perikarya also contain fluorescing material. They form a single bundle which passes under the preoptic recess, than splits into two tracts, one on either side of the optic chiasm. The two tracts reunite just before entering the median eminence. The axons end near the capillaries in the outer zone of the median eminence. The possibility of two separate centres for the stimulation of gonadotropic activity in the brains of anurans is discussed.

  13. [Analysis of helminthofauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) at their joint habitation].

    Science.gov (United States)

    Ruchin, A B; Chikhliaev, I V; Lukiianov, S V

    2009-01-01

    The helminths fauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 has been studied at their joint habitation. The stuff was collected in 1998-2002, 2004-2006 years in several regions (republic Mordovia, Samara and Saratov areas). The processing of a stuff is conducted by a method of full helmintologic dissecting. The fauna of helminths considerably differs. For common spaedfoot only 13 species of helminths was detected which also parasitized moor frog (for moor frog 23 species) are detected. The index Jaccar demonstrated mean resemblance structure of helminths and varied from 0.25 till 0.69, and the index Morisite--from 44.58 of % till 74.51 of %. The communities of parasites of common spaedfoot was characterized by low values of an index of Shannon, but the high indexes of an index Simpson, whereas for moor frog tracked the return tendence.

  14. 林蛙油多肽粉的配方优化及冲调特性研究%Formulation optimization of oviductus ranae polypeptide powder

    Institute of Scientific and Technical Information of China (English)

    叶海青; 徐向秀; 张铁华; 奚春宇; 张兴; 李玺

    2014-01-01

    Objective To improve the physical and dissolution properties of oviductus ranae. Methods Determined the viscosity, emulsifying activity, emulsion stability and centrifugal sedimentation rate of poly-peptide powder, which was emulsified after the deployment of complex enzymatic liquid and dried by freeze drying and spray drying. Results Optimal formula: malt dextrin: β-cyclodextrin: whey protein concentrate (WPC80)=1:4:5, glycerin monostearate was 0.05%. Compared to lyophilized enzyme solution , the compound freeze-drying oviductus ranae polypeptide powder was increased by 3.43% in solubility, dropped 23.72% in moisture content, 56.10%in hygroscopic rate and 42.33%in the dissolution property;compared to the enzyme solution directly spray dried powder, the compound spray-drying oviductus ranae polypeptide powder was in-creased by 2.40%in solubility, dropped 25.72%in moisture content, 46.15%in hygroscopic rate and 35.53%in the dissolution property. Conclusion After compounding, the solubility of oviductus ranae polypeptide powder is increased, the moisture absorption is lower, and the brewing performance is perfecter. The quality characteristics of polypeptide powder prepared by spray drying quality characteristics is betteer than freeze-dried preparation of peptide powder.%目的:改善林蛙油多肽粉的物理性质和冲调特性。方法对林蛙油酶解液复合调配后进行乳化工艺处理,采用冷冻干燥和喷雾干燥两种方法进行干燥制粉,以黏度、乳化活性、乳化稳定性、离心沉淀率为指标,确定了林蛙油酶解液制备林蛙油多肽粉的最优配方。结果林蛙油多肽粉的最优配方:β-环状糊精:麦芽糊精:乳清浓缩蛋白粉(WPC80)的添加比为1:4:5、单甘酯0.05%。研究结果表明,与酶解液直接冻干粉相比较,复配及乳化处理后冷冻干燥制得的林蛙油多肽粉水分含量下降23.72%,吸湿率下降56.10%,溶解度提升3.43%,分散时间缩短42

  15. Spatial Amphibian Impact Assessment – a management tool for assessment of road effects on regional populations of Moor frogs (Rana arvalis)

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt; Nachman, Gøsta Støger

    2013-01-01

    An expanding network of roads and railways fragments natural habitat affecting the amount and quality of habitat and reducing connectivity between habitat patches with severe consequences for biodiversity and population persistence. To ensure an ecologically sustainable transportation system......), to be used as a standardized and quantitative tool for assessing the impact of roads on pond-breeding amphibians. The model considers a landscape mosaic of breeding habitat, summer habitat and uninhabitable land. As input, we use a GIS-map of the landscape with information on land cover as well as data...... demonstrate how SAIA can be used to assess which management measures would be best to mitigate the effect of landscape fragmentation caused by road constructions by means of a case study dedicated to the Moor frog (Rana arvalis)....

  16. Toxicity of the conventional energetics TNT and RDX relative to new insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    Science.gov (United States)

    Stanley, Jacob K; Lotufo, Guilherme R; Biedenbach, James M; Chappell, Pornsawan; Gust, Kurt A

    2015-04-01

    An initiative within the US military is targeting the replacement of traditional munitions constituents with insensitive munitions to reduce risk of accidental detonation. The purpose of the present study was to comparatively assess toxicity of the traditional munitions constituents 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) with the new insensitive munitions constituents 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The following exposure durations were performed with Rana pipiens (leopard frog) tadpoles: TNT and DNAN, 96 h and 28 d; RDX, 10 d and 28 d; NTO, 28 d. The 96-h 50% lethal concentration (LC50) values and 95% confidence intervals for TNT and DNAN were 4.4 mg/L (4.2 mg/L, 4. 7 mg/L) and 24.3 mg/L (21.3 mg/L, 27.6 mg/L), respectively. No significant impacts on survival were observed in the 10-d exposure to RDX up to 25.3 mg/L. Effects on tadpole swimming distance were observed with a lowest-observed-effect concentration (LOEC) of 5.9 mg/L RDX. In the 28-d exposures, the LOECs for survival for TNT, DNAN, and NTO were 0.003 mg/L, 2.4 mg/L, and 5.0 mg/L, respectively. No significant mortality was observed in the RDX chronic 28-d exposure up to the highest treatment level tested of 28.0 mg/L. Neither tadpole developmental stage nor growth was significantly affected in any of the 28-d exposures. Rana pipiens were very sensitive to chronic TNT exposure, with an LOEC 3 orders of magnitude lower than those for insensitive munitions constituents DNAN and NTO.

  17. Extraction of Rana Chensinensis Skin Collagen by Papain and its Antioxidant Activity%林蛙皮胶原蛋白的提取及抗氧化性

    Institute of Scientific and Technical Information of China (English)

    吕玲玲; 金香淑; 施溯筠

    2013-01-01

      Extraction of Rana Chensinensis skin collagen by papain and its antioxidant activity were studied in this paper. The results of the single factor experiment and orthogonal test were as follows: the hydrolysis temperature of room temperature, reaction time of 36 h, pH of 5.5, enzyme concentration of 1%and the ratio of solid to liquid 1∶20 (g/mL). Its recovery yield was 24.71%and the degree of puirty was 72.03%. Collagen of Rana Chensinensis Skin had strong reducing capacity and antioxidant activity on scavenging hydroxyl free radical effects .%  用木瓜蛋白酶提取林蛙皮胶原蛋白,采用单因素试验和正交试验设计优选最佳提取工艺,并对林蛙皮胶原蛋白的抗氧化性进行研究。结果表明:林蛙皮胶原蛋白的最佳提取工艺是加酶量为1%,料液比为1∶20(g/mL),pH为5.5于室温反应36 h,此条件下胶原蛋白提取率为24.71%,纯度为72.03%。林蛙皮胶原蛋白具有一定的还原能力,对羟自由基具有一定的清除能力,并且随着浓度的增加抗氧化活性逐渐增强。

  18. The role of thyroid hormone in the regulation of hepatic carbamyl phosphate synthetase activity in Rana catesbeiana.

    Science.gov (United States)

    Galton, V A; Morganelli, C M; Schneider, M J; Yee, K

    1991-11-01

    Both spontaneous and thyroid hormone (TH)-induced metamorphosis of Rana catesbeiana are accompanied by a marked increase in the activity of the urea cycle enzyme carbamyl phosphate synthetase (CPS). The increase induced by exogenous TH is de novo synthesis of enzyme and appears to be secondary to an increase in the CPS mRNA level resulting from the elevated plasma TH. Since endogenous TH levels rise sharply during spontaneous metamorphosis, a similar sequence of events would be anticipated. However, after midclimax, CPS activity continues to increase, while plasma TH levels steadily decline, suggesting that other factors are involved. To obtain insight into this problem, the changes in CPS mRNA level during spontaneous development were determined using a mammalian CPS cDNA probe and correlated with changes in CPS activity and plasma T3 concentration. CPS mRNA level and CPS activity were barely detectable until midprometamorphosis, but both increased rapidly during the latter half of this phase. CPS activity continued to rise, reaching a maximum in the adult frog. The CPS mRNA level, however, was highest during the first half of climax, but declined after midclimax and was relatively low in the adult frog. Studies were also performed in which the rise and fall in the plasma T3 concentration typical of metamorphic climax were induced by exposure of premetamorphic tadpoles to T3, followed by its withdrawal. Both CPS activity and CPS mRNA level were induced by T3, but when plasma T3 levels fell after removal of the exogenous T3, CPS mRNA level, but not CPS activity, also decreased. Additional studies indicated that the TH-induced increase in CPS mRNA was evident within 24 h, could be prevented by simultaneous injection of actinomycin-D, and could not be induced in tadpoles undergoing climax; in this phase the T3 receptors are fully occupied with endogenous TH. When premetamorphic tadpoles were immersed in T3-containing water (0-500 nM) for 6 days, CPS mRNA, CPS

  19. Supplementary studies of Pleurogenoides medians (Digenea: Lecithodendriidae infecting the Marsh frog Rana Ridibunda (Amphibia: Ranidae in Egypt

    Directory of Open Access Journals (Sweden)

    Rewaida Abdel-Gaber

    2017-06-01

    Full Text Available Pleurogenoides medians, a digenean lecithodendriid trematode, parasitize numerous aquatic vertebrate species including frogs, freshwater fish, urodeles and anurans. In the present study, a total of 190 out of 300 (63.33% marsh frogs Rana Ridibunda were found to be infected with this digenean parasite. The highest percentage of infection was recorded in winter reaching 93.33%, and the lowest value was recorded to be 6.66% during summer. Prevalence and intensity of infection were positively correlated with the host size. Host sex showed no effect in this respect. Morphological studies based on light and scanning electron microscopy revealed that the adult worms characterized by small body size measured 1.980–2.430 (2.205 ± 0.1 mm long and 0.870–1.20 (9.87 ± 0.01 mm wide with spines of similar size distributed all over the body surface; oral sucker is sub-terminal and measured 0.180–0.230 (0.203 ± 0.01 mm long and 0.120–0.180 (0.150 ± 0.01 mm wide; ventral sucker is smaller than the oral sucker, post-ovarian located at 1/3 level from the anterior end and measured 0.080–0.102 (0.090 ± 0.001 mm long and 0.100–0140 (0.120 ± 0.001 mm wide; two symmetrical testes were located near the cecal termination on both sides of the ventral sucker, measured 0.153–0.193 (0.176 ± 0.01 mm long and 0.160–0.192 (0.175 ± 0.01 mm wide; pre-acetabular ovary was present and measured 0.130–0.150 (0.140 ± 0.01 mm long and 0.100–0.130 (0.120 ± 0.01 mm wide; vitellaria are extra-caecal and extended from the level of the pharynx to a level slightly beyond the ovary. By comparing the recovered parasite with different species of the same genus from different hosts having different localities, it was found that the present species morphometrically more or less different from the comparable species and the only similar species was P. medians described previously from the common toad Bufo bufo by having all similar

  20. 中国林蛙属(无尾目:蛙科)一新种——寒露林蛙Rana hanluica sp.nov.%A new species of the genus Rana——Rana hanluica sp. nov. from Hunan Province, China(Anura: Ranidae)

    Institute of Scientific and Technical Information of China (English)

    沈猷慧; 江建平; 杨道德

    2007-01-01

    本文报道两栖纲蛙科一新种,新种具林蛙属(Rana)特征,与昭觉林蛙种组(费梁,1999)相近,但与该组成员又有明显区别,被命名为寒露林蛙Rana hanluica sp. nov..新种有系列特征与峨眉林蛙(R.omeimonts)、昭觉林蛙(R.chaochiaoensis)相似,但又明显不同于后者,如:1)无雄性线;2)蝌蚪唇齿式为Ⅰ:3+3/1+1: Ⅲ;3)股部背侧黑褐色横斑窄,通常整齐、数目较多;4)繁殖季节在农历寒露节前后.这些特征可以与峨眉林蛙、昭觉林蛙准确区别.新种标本采自湖南省双牌县阳明山,模式标本保存在湖南师范大学动物标本馆及中国科学院成都生物研究所[动物学报 53(3):481-488,2007].

  1. Adapting American Policymaking to Overcome American Exceptionalism

    Science.gov (United States)

    2015-04-13

    missions, and of military operations spanning administrations. In conclusion, an apologist posture to defend American foreign policies is not called...military operations spanning administrations. In conclusion, an apologist posture to defend American foreign policies is not called for. However, a deep...and brings to light the tension between American ideals and American practices and policies. V/ hen exposed, this tension opens the door for American

  2. Response Surface Method to Optimize the Process Parameters of Acid-enzyme Combination Extraction Bullfrog Skin Collagen%响应面法优化酸酶结合提取牛蛙皮胶原蛋白工艺参数

    Institute of Scientific and Technical Information of China (English)

    张丹鹤; 刘学军

    2012-01-01

    In order to make full use of bullfrog skin resources, in this experiment through determination of hydrgxyproline content determines the bullfrog skin collagen in a total of 42.58%, drawing the standard curve obtained collagen hydroxyproline, which content is 28.32%, the bullfrog skin aiker pretreatment with acetic acid and pepsin extraction, combination, and the use of response surface method to the extraction conditions for process optimization, the results show that: the optimum extraction conditions for l0 DEG C, at the concentration of 2.5 per 1000pepsin, in 1:40ratio of material to liquid, extraction of 24h. The optimum conditions of collagen extraction, and by the salting out, freezing and drying to obtain powdered collagen products. Its measured rate is 27.98%. The extracted bullfrog skin collagen by ultraviolet analysis and detection of amino acids, the results show that the extraction of high purity collagen products.%为了充分利用牛蛙皮资源,本试验通过测定羟脯氨酸含量确定了牛蛙皮中胶原蛋白总量为42.58%,绘制羟脯氨酸标准曲线,得出其中胶原蛋白含量为28.32%,牛蛙皮经过预处理后,采用乙酸和胃蛋白酶结合提取,并利用响应面法对提取条件进行工艺优化,结果表明:最佳提取条件为10℃下,以浓度为2.5‰的胃蛋白酶,在1:40料液比中,提取24h。以最佳条件提取胶原蛋白,并经盐析、冷冻干燥得到粉末状胶原蛋白产品。测得其得率为27.98%。对所提取的牛蛙皮胶原蛋白进行紫外分析和氨基酸检测,结果表明所提取的胶原蛋白产品纯度较高。

  3. 哈蟆油发酵乳中蛋白质及氨基酸含量分析%Analysis of protein and amino acid content of Oviductus Ranae in fermented milk

    Institute of Scientific and Technical Information of China (English)

    刘同帅; 邱智东; 翁丽丽; 郝洁; 翁砚

    2016-01-01

    Objective To establish a method for analysis of protein and amino acidcontent of Ranae Oviductus fermented milk. Methods Using Coomassie bright blue for determination of Ranae Oviductus fermented milk protein content,determination of the content of amino acids by automatic amino acid analyzer. Results The three batch of Ranae Oviductus fermented milk protein content were 8. 050 1,8. 093 0,7. 758 2 mg/mL. The average total amino acid content was 15. 320 5 mg/mL. Conclusion Ranae Oviductus in fermented milk containing synthetic human body needs protein rich amino acids.%目的:建立哈蟆油发酵乳中蛋白质及氨基酸含量分析方法。方法运用考马斯亮蓝法测定哈蟆油发酵乳中蛋白质含量,运用氨基酸自动分析仪测定哈蟆油发酵乳中氨基酸的含量。结果3批哈蟆油发酵乳蛋白含量分别为8.0501、8.0930、7.7582 mg/mL。平均总氨基酸的含量为15.3205 mg/mL。结论哈蟆油发酵乳中含有合成人体所需蛋白质及丰富的氨基酸。

  4. Rações comerciais e o rendimento de carcaça e subprodutos de rã-touro Commercial food and the carcass yield and by-products of bullfrog

    Directory of Open Access Journals (Sweden)

    Alex Poeta Casali

    2005-10-01

    Full Text Available Objetivou-se avaliar o efeito do sexo e do uso de quatro rações comerciais extrusadas (R1, R2, R3 e R4 e uma ração peletizada (R5 sobre o rendimento de carcaça e aproveitamento de subprodutos da ranicultura, após 56 dias de experimentação. As rações comerciais eram recomendadas para diferentes espécies e fases de desenvolvimento animal, a saber: R1 = para rãs (na fase inicial, imagos; R2 = para peixes onívoros (em fase inicial; R3 = para trutas (peixe carnívoro na fase de crescimento; e R4 = para trutas (na fase inicial. Foram analisados os teores (% de matéria seca (MS, proteína bruta (PB, extrato etéreo (EE, fibra bruta (FB e matéria mineral (MM das rações. Foram utilizadas 80 rãs-touro com peso médio inicial de 51,57g distribuídas em um delineamento em blocos casualizados em esquema fatorial (cinco rações X dois sexos com oito repetições de uma rã por unidade experimental. Não houve significância na interação entre os fatores para todas as variáveis analisadas. Os menores valores de rendimento de carcaça foram observados nos animais que receberam a ração R3, sendo as demais iguais. No aproveitamento de subprodutos, destacou-se a ração R1, que proporcionou maior peso de fígado e descartes, e a ração R4, com maior peso de fígado e corpo gorduroso. O sexo dos animais apenas influenciou no aproveitamento de descartes, sendo que os machos proporcionaram maiores médias.The objective was to evaluate the effect of the sex and the use of four commercial extruded foods (R1, R2, R3, and R4 and a pelleted food (R5 on the carcass yield and the by-product utilization of the bullfrog culture, after 56 days of experimentation. The commercial foods were recommended to different species or phases of growth: R1 = for frogs in the initial phase; R2 = for omnivorous fish in the initial phase; R3 = for trout (carnivorous fish in phase of growth; and R4 = for trout in initial phase. The chemical composition (DM, CP, EE, CF

  5. RNase activity of sialic acid-binding lectin from bullfrog eggs drives antitumor effect via the activation of p38 MAPK to caspase-3/7 signaling pathway in human breast cancer cells

    Science.gov (United States)

    Kariya, Yukiko; Tatsuta, Takeo; Sugawara, Shigeki; Kariya, Yoshinobu; Nitta, Kazuo; Hosono, Masahiro

    2016-01-01

    Sialic acid-binding lectin obtained from bullfrog eggs (SBL) induces cell death in cancer cells but not in normal cells. This antitumor effect is mediated through its ribo-nuclease (RNase) activity. However, the underlying molecular mechanisms remain unclear. We found that the p38 mitogen-activated protein kinase (MAPK) signaling pathway was activated when SBL induced cell death in three human breast cancer cell lines: SK-BR-3, MCF-7, and MDA-MB231. The suppression of p38 MAPK phosphorylation by a p38 MAPK inhibitor as well as short interference RNA knockdown of p38 MAPK expression significantly decreased cell death and increased the cell viability of SBL-treated MDA-MB231 cells. H103A, an SBL mutant lacking in RNase activity, showed decreased SBL-induced cell death compared with native SBL. However, the loss of RNase activity of SBL had no effect on its internalization into cells. The H103A mutant also displayed decreased phosphorylation of p38 MAPK. Moreover, SBL promoted caspase-3/7 activation followed by a cleavage of poly (ADP-ribose)-polymerase, whereas the SBL mutant, H103A, lost this ability. The SBL-induced caspase-3/7 activation was suppressed by the p38 MAPK inhibitor, SB203580, as well as pan-caspase inhibitor, zVAD-fmk. In the presence of zVAD-fmk, the SBL-induced cell death was decreased. In addition, the cell viability of SBL-treated MDA-MB231 cells recovered by zVAD-fmk treatment. Taken together, our results suggest that the RNase activity of SBL leads to breast cancer cell death through the activation of p38 MAPK followed by the activation of caspase-3/7. PMID:27513956

  6. RNase activity of sialic acid-binding lectin from bullfrog eggs drives antitumor effect via the activation of p38 MAPK to caspase-3/7 signaling pathway in human breast cancer cells.

    Science.gov (United States)

    Kariya, Yukiko; Tatsuta, Takeo; Sugawara, Shigeki; Kariya, Yoshinobu; Nitta, Kazuo; Hosono, Masahiro

    2016-10-01

    Sialic acid-binding lectin obtained from bullfrog eggs (SBL) induces cell death in cancer cells but not in normal cells. This antitumor effect is mediated through its ribonuclease (RNase) activity. However, the underlying molecular mechanisms remain unclear. We found that the p38 mitogen-activated protein kinase (MAPK) signaling pathway was activated when SBL induced cell death in three human breast cancer cell lines: SK-BR-3, MCF-7, and MDA‑MB231. The suppression of p38 MAPK phosphorylation by a p38 MAPK inhibitor as well as short interference RNA knockdown of p38 MAPK expression significantly decreased cell death and increased the cell viability of SBL-treated MDA‑MB231 cells. H103A, an SBL mutant lacking in RNase activity, showed decreased SBL-induced cell death compared with native SBL. However, the loss of RNase activity of SBL had no effect on its internalization into cells. The H103A mutant also displayed decreased phosphorylation of p38 MAPK. Moreover, SBL promoted caspase‑3/7 activation followed by a cleavage of poly (ADP-ribose)-polymerase, whereas the SBL mutant, H103A, lost this ability. The SBL-induced caspase‑3/7 activation was suppressed by the p38 MAPK inhibitor, SB203580, as well as pan-caspase inhibitor, zVAD-fmk. In the presence of zVAD-fmk, the SBL-induced cell death was decreased. In addition, the cell viability of SBL-treated MDA‑MB231 cells recovered by zVAD-fmk treatment. Taken together, our results suggest that the RNase activity of SBL leads to breast cancer cell death through the activation of p38 MAPK followed by the activation of caspase‑3/7.

  7. Elevage commercial de grenouilles en Malaisie

    Directory of Open Access Journals (Sweden)

    Hardouin, J.

    1997-01-01

    Full Text Available Commercial Frog Production in Malaysia. Commercial frog farms exist in several countries. It seems hopeless believing that frog leg consumption can be prohibited, and the solution is probably a very strict control of the origin of the legs sold and imported. Uncontrolled hunting-poaching of frogs should be replaced by sustainable and rational breeding of frogs for sale. A large frog farm located near Singapore is described with the infrastructure and the management of the production. The two species bred are the American and the Asian bull-frogs Rana catesbeiana and R. tigerina. It is also mentioned that appropriate slaughtering techniques exist for frogs based on same guidelines as for conventional farm animals.

  8. Exploitation des larves de sardine Limnothrissa miodon au lac Kivu (R.D.C. : danger potentiel ?

    Directory of Open Access Journals (Sweden)

    Kaningini, M.

    1997-01-01

    Full Text Available Larva's Catch of Sardine Limnothrissa miodon in Lake Kivu (RD Congo : Potential Danger ?. Commercial frog farms exist in several countries. It seems hopeless believing that frog leg consumption can be prohibited, and the solution is probably a very strict control of the origin of the legs sold and imported. Uncontrolled hunting-poaching of frogs should be replaced by sustainable and rational breeding of frogs for sale. A large frog farm located near Singapore is described with the infrastructure and the management of the production. The two species bred are the American and the Asian bull-frogs Rana catesbeiana and R. tigerina. It is also mentioned that appropriate slaughtering techniques exist for frogs based on same guidelines as for conventional farm animals.

  9. Morfologfa conchffera, crecimiento, reproducción y letargo de los caracoles gigantes africanos : observaciones en laboratorio sobre Archachatina marginata suturalis, Achatina achatina y Achatina fulica'

    Directory of Open Access Journals (Sweden)

    Stiévenart, C.

    1997-01-01

    Full Text Available hell Shape, Growth, Reproduction and Estivation in Giant African Landsnails : Observations in Laboratory on"Archachatina marginata suturalis, Achatina achatina and Achatina fulica". Commercial frog farms exist in several countries. It seems hopeless believing that frog leg consumption can be prohibited, and the solution is probably a very strict control of the origin of the legs sold and imported. Uncontrolled hunting-poaching of frogs should be replaced by sustainable and rational breeding of frogs for sale. A large frog farm located near Singapore is described with the infrastructure and the management of the production. The two species bred are the American and the Asian bull-frogs Rana catesbeiana and R. tigerina. It is also mentioned that appropriate slaughtering techniques exist for frogs based on same guidelines as for conventional farm animals.

  10. Native Americans with Diabetes

    Science.gov (United States)

    ... Read the MMWR Science Clips Native Americans with Diabetes Better diabetes care can decrease kidney failure Language: ... between 1996 and 2013. Problem Kidney failure from diabetes was highest among Native Americans. Native Americans are ...

  11. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  12. 两种无尾类发声器官的初步观察%Preliminary observation of vocal organs of two anurans (Rana chensinensis and Bufo raddei)(Anura)

    Institute of Scientific and Technical Information of China (English)

    张雷; 赵梓伊; 陆宇燕; 李丕鹏; 宋阳; 周正彦; 周兵; 杨宝田; 董丙君

    2012-01-01

    Vocal organs in Rana chensinensis were preliminarily compared with Bufo raddei with anatomic and histological methods. The results shown that Rana chensinensis had cartilago prearytenoedeas and pulvinaria vocalias, but Bufo raddei did not have. The lateral portions of vocal cords in Bufo raddei were a pair of membranes composed of dense regular connective tissues, and in the mid of medial portion of vocal cords in Bufo raddei there are a pair of fibrious masses. At the end of laryngeal chambers Bufo raddei there are also a pair of posterior membrances. But the lateral portions of vocal cords in Rana chensinensis were composed of dense irregular connective tissues and had no posterior membrances. The difference of areas in medial portions of vocal cords were apparent in Rana chensinensis but in Bufo raddei no this character. The type of vocal sacs in Rana chensinensis was inner vocal sacs lateral to pharynx, but in Bufo raddei it was inner vocal sacs under pharynx. Compared with the two(Rana chensinensis and Bufo raddei) relative length and width of medial portions of vocal cords and laryngeal chambers, the results have statistics significance. In discussion, we analysized the influence of both vocal organs on sound production and it would supply basic information to understand the sounds difference in Bufonids and Ranids.%应用大体解剖和组织学方法对中国林蛙(Rana chensinensis)和花背蟾蜍(Bufo raddei)的发声器官进行了初步观察和比较.结果表明:中国林蛙有独立的前杓状软骨和枕声带,而花背蟾蜍则没有上述结构.花背蟾蜍的声带侧部为规则致密结缔组织构成的膜状结构,并且前端有一对肉质化的纤维小球,喉室末端有一对后膜,而中国林蛙的声带侧部由无规则致密结缔组织构成的肉质化纤维柱状结构,喉室的末端无后膜结构.前者的声带中部为一对厚度均匀的膜系结构.而后者声带中部在不同区域也存在明显的差异,中国林

  13. Tricaine (MS-222) is a safe anesthetic compound compared to benzocaine and pentobarbital to induce anesthesia in leopard frogs (Rana pipiens).

    Science.gov (United States)

    Cakir, Yavuz; Strauch, Stephen M

    2005-01-01

    Tricaine (MS-222) is used commonly for sedation, immobilization, and anesthesia of poikilothermic animals. The anesthetic efficacy of different concentrations of MS-222 was compared to benzocaine and pentobarbital on the physiological changes, heart rate and ECG (electrocardiogram) parameters in the leopard frog, Rana pipiens. Loss of righting reflex (RR), loss of pain response (NR = nociceptor response) and recovery time were measured. Heart rate and ECG parameters were also tested before and during anesthesia. The time to loss of RR and NR decreased while recovery time markedly increased with the increasing concentration of MS-222. Benzocaine at 200 mg/l induced a rapid anesthesia, but all frogs needed resuscitation. Pentobarbital at 300 mg/l induced a slow anesthesia, however, all of the frogs also needed resuscitation. All anesthetics at the mentioned concentrations decreased heart rate significantly as well as altered the ECG parameters. All anesthetics prolonged the Q-T interval, and MS-222 at 800 mg/l and benzocaine at 200 mg/l were the most effective anesthetic concentrations in increasing the Q-T interval. Frogs anesthetized by benzocaine and pentobarbital and high concentrations of MS-222 required resuscitation due to hypoxia. Pentobarbital and benzocaine seem to be very effective compounds, but their safety margins are narrow because of ventilatory failure. Therefore, MS-222 at a concentration of 200 mg/l or less is highly recommended for leopard frogs because prolonged recovery, high mortality rate and significant ECG changes are observed with higher concentrations of MS-222.

  14. Bioaccumulation kinetics of the conventional energetics TNT and RDX relative to insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    Science.gov (United States)

    Lotufo, Guilherme R; Biedenbach, James M; Sims, Jerre G; Chappell, Pornsawan; Stanley, Jacob K; Gust, Kurt A

    2015-04-01

    The manufacturing of explosives and their loading, assembling, and packing into munitions for use in testing on training sites or battlefields has resulted in contamination of terrestrial and aquatic sites that may pose risk to populations of sensitive species. The bioaccumulative potential of the conventional explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and of the insensitive munitions (i.e., less shock sensitive) compound 2,4-dinitroanisole (DNAN) were assessed using the Northern leopard frog, Rana pipiens. Trinitrotoluene entering the organism was readily biotransformed to aminodinitrotoluenes, whereas no transformation products were measured for RDX or DNAN. Uptake clearance rates were relatively slow and similar among compounds (1.32-2.19 L kg(-1) h(-1) ). Upon transfer to uncontaminated water, elimination rate was very fast, resulting in the prediction of fast time to approach steady state (5 h or less) and short elimination half-lives (1.2 h or less). A preliminary bioconcentration factor of 0.25 L kg(-1) was determined for the insensitive munitions compound 3-nitro-1,2,4-trizole-5-one (NTO) indicating negligible bioaccumulative potential. Because of the rapid elimination rate for explosives, tadpoles inhabiting contaminated areas are expected to experience harmful effects only if under constant exposure conditions given that body burdens can rapidly depurate preventing tissue concentrations from persisting at levels that may cause detrimental biological effects.

  15. Analysis of skin and secretions of Dybowski's frogs (Rana dybowskii) exposed to Staphylococcus aureus or Escherichia coli identifies immune response proteins.

    Science.gov (United States)

    Xiao, Xiang-Hong; Miao, Hui-Min; Xu, Yi-Gang; Zhang, Jing-Yu; Chai, Long-Hui; Xu, Jia-Jia

    2014-04-01

    The aim of the present study was to investigate responses in Dybowski's frogs (Rana dybowskii) exposed to bacteria, using proteomic and transcriptomic approaches. Staphylococcus aureus and Escherichia coli were used as representative Gram-positive and Gram-negative bacteria, respectively, in an infectious challenge model. Frog skin and skin secretions were collected and protein expression in infected frogs compared to control frogs by two-dimensional gel electrophoresis, silver staining, and image analysis. Proteins that demonstrated differential expression were analysed by mass spectrometry and identified by searching protein databases. More than 180 protein spots demonstrated differential expression in E. coli- or S. aureus-challenged groups and, of these, more than 55 spots were up- or down-regulated at least sixfold, post-infection. Proteins with a potential function in the immune response were identified, such as stathmin 1a, annexin A1, superoxide dismutase A, C-type lectin, lysozyme, antimicrobial peptides, cofilin-1-B, mannose receptor, histone H4, prohormone convertase 1, carbonyl reductase 1 and some components of the Toll-like receptor (TLR) signalling pathway. These molecules are potential candidates for further investigation of immune mechanisms in R. dybowskii; in particular, TLR-mediated responses, which might be activated in frogs exposed to pathogenic bacteria as part of innate immune defence, but which might also impact on adaptive immunity to infection.

  16. Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China.

    Science.gov (United States)

    Li, Long; Wang, Wenyue; Lv, Quanxia; Ben, Yujie; Li, Xinghong

    2014-03-01

    Dechlorane Plus (DP), a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs (DPs) were detected in the liver, muscle and brain tissues of wild frogs (Rana limnocharis), which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP (anti-Cl11-DP) varied in the range of 2.01-291, 0.650-179, 0.260-12.4, and not detected (nd)-8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue (liver/muscle concentration ratio close to 1, p > 0.05). However, higher retention was observed for anti-DP and anti-Cl11-DP in the frog muscle relative to the liver tissue (liver/muscle concentration ratio 1, p frog.

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

    Directory of Open Access Journals (Sweden)

    Ewa Krzysztofowicz

    2011-08-01

    Full Text Available Total numbers of mitochondria and their morphology have been quantitatively determined in mature oocytes and in cleaving embryos of two anuran species Rana temporaria and Bufo bufo using stereological methods. Surface densities of inner mitochondrial membranes for both studied species during cleavage ranged from 5.43 m2/cm3 to 7.53 m2/cm3, whereas volume densities of mitochondria did not exceed 1.65%. Since values of these parameters were low, thus embryos during cleavage may be considered as metabolically "silent". Transition of ultrastructural morphology of mitochondria towards that characterising actively respiring organelles occurs at stage 9 for R. temporaria and at stage 8 for B. bufo, correlated with blastula-gastrula and mid-blastula transition, respectively. The total numbers of mitochondria N(c in mature oocytes are as high as 114.8 and 107.2 millions for R. temporaria and B. bufo, respectively, and during cleavage at late blastula stages they increase to 300 millions for both species under study. We suggest that an undefined mechanism might eliminate during cleavage those amphibian embryos which contain small number of mitochondria and low levels of nutrient substances.

  18. An X-linked body color gene of the frog Rana rugosa and its application to the molecular analysis of gonadal sex differentiation.

    Science.gov (United States)

    Miura, I; Kitamoto, H; Koizumi, Y; Ogata, M; Sasaki, K

    2011-01-01

    We identified a sex-linked, recessive body color gene, presently designated w (whitish-yellow), in the frog Rana rugosa from the Iwakuni population in Western Japan. This is the first time a sex-linked body color gene was found in amphibians so far. In this population of R. rugosa, males are the heterogametic sex, but the sex chromosomes are still homomorphic. When heterozygous males (Ww), which were produced by crossing a whitish-yellow female (ww) found in the field and a wild-type male (WW) of the same population, were backcrossed to the homozygous whitish-yellow female (ww), the resultant male offspring were all wild-type, whereas the females were all whitish-yellow. This result definitely indicates that w is recessive and X-linked, and its wild-type allele W is located on the Y chromosome. Using this strain (X(w)X(w) female and X(w)Y(W) male), we found that expression of Dmrt1 and Rspo1, which are involved in testicular and ovarian differentiation in vertebrates, was higher in males and females, respectively, prior to the onset of the sexually dimorphic expression of Cyp17 and Cyp19, which are involved in biosynthesis of sex steroids and are critical markers of gonadal sex differentiation.

  19. The prevalence and risk factors of Post-Traumatic Stress Disorder among workers injured in Rana Plaza building collapse in Bangladesh.

    Science.gov (United States)

    Fitch, Taylor; Villanueva, Gabriela; Quadir, Mohammad M; Sagiraju, Hari K R; Alamgir, Hasanat

    2015-07-01

    Prevalence and risk factors of PTSD among injured garment workers who survived a major factory collapse. Survivors receiving treatment or rehabilitation care at one year post event were surveyed, which included Post Traumatic Stress Disorder Checklist Specific version. The respondents consisted of 181 people with a mean age of 27.8 years and a majority had less than high school education (91.2%). Multivariable logistic regression found that the odds of having PTSD was higher among married (OR: 3.2 [95% CI: 1.3-8.0]), those who used to work more than 70 hr/week (OR: 2.4 [1.1-5.3]), workers who used to hold higher job positions (OR: 2.6 [1.2-5.6]) or who had a concussion injury (OR: 3.7 [1.4-9.8]). Among the respondents, 83.4% remained unemployed, and only 57.3% (63 people) reported receiving a quarter or less of what they were promised as compensation. Probable PTSD was prevalent among surviving workers of the Rana Plaza building collapse in Bangladesh. © 2015 Wiley Periodicals, Inc.

  20. Density-dependent growth and metamorphosis in the larval bronze frog Rana temporalis is influenced by genetic relatedness of the cohort

    Indian Academy of Sciences (India)

    S Girish; S K Saidapur

    2003-06-01

    Effects of density and kinship on growth and metamorphosis in tadpoles of Rana temporalis were studied in a 2 × 4 factorial experiment. Fifteen egg masses were collected from streams in the Western Ghat region of south India. The tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz. 15, 30, 60 and 120/5 l water. With an increase in density level from 15 to 120 tadpoles/5 l water, duration of the larval stage increased and fewer individuals metamorphosed irrespective of whether they belonged to sibling or non-sibling groups by day 100 when the experiments were terminated. The size of individuals at metamorphosis declined significantly with increase in the density of rearing. However, at higher densities (60 and 120 tadpoles/5 l water) sibling group tadpoles performed better compared to mixed groups and took significantly less time to metamorphose. Also, more individuals of sibling groups metamorphosed compared to non-sibling groups at a given density. Mixed rearing retarded growth rates, prolonged larval duration resulting in a wider spectrum of size classes, and lowered the number of individuals recruited to terrestrial life. The study shows that interference competition occurred more strongly in cohorts of mixed relatedness than in sibling groups.

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

    Directory of Open Access Journals (Sweden)

    Dag Dolmen

    2016-04-01

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

  2. Immunocytochemical and ultrastructural characterization of endocrine cells in the larval stomach of the frog Rana temporaria tadpoles: a comparison with adult specimens.

    Science.gov (United States)

    Villaro, A C; Rovira, J; Bodegas, M E; Burrell, M A; García-Ros, D; Sesma, P

    2001-10-01

    According to immunostaining and ultrastructural patterns, Rana temporaria tadpole stomach displays a well-differentiated endocrine population comprising, at least, six cellular types: ECL, EC [serotonin], D [somatostatin] - all three of them abundant -, P [bombesin] - less numerous -, CCK-8 [cholecystokinin/gastrin] and A [glucagon/glicentin] - both very scarce. Larval endocrine cells are mainly located in the surface epithelium and show open or closed morphologies. Cellular diversity is similar in tadpoles and frogs, with the exception of immunoreactivity for gastrin-17, found in adults in numerous cells. Larval cells display mature ultrastructural traits, although with smaller secretory granules. The different distribution of endocrine cells, which in adults are preferentially located in the glands, probably refers to different functional requirements. However, the rich vascular plexus present in larval mucosa may be an efficient transport medium of surface hormones to-gastric targets. The enhancement in adults of endocrine population and correlative increase in hormonal secretion indicates a more active functional role, probably related to the shift from herbivorous to carnivorous habits. In summary, the tadpole gastric endocrine population, although not as numerous as that of adult frogs, displays histological traits that indicate a relevant (immunoreactive and ultrastructural properties, cellular diversity) and specific (surface location, relative abundance of open-type cells) role of local regulatory factors in amphibian larval gastric function.

  3. Immunoreactivities of IL-1β and IL-1R in oviduct of Chinese brown frog (Rana dybowskii) during pre-hibernation and the breeding period.

    Science.gov (United States)

    Hu, Ruiqi; Liu, Yuning; Deng, Yu; Ma, Sihui; Sheng, Xia; Weng, Qiang; Xu, Meiyu

    2016-03-01

    The Chinese brown frog (Rana dybowskii) has one special physiological phenomenon, which is that its oviduct goes through expansion prior to hibernation instead of during the breeding period. In this study, we investigated the localization and expression level of interleukin-1 (IL-1β) and its functional membrane receptor type I (IL1R1) proteins in the oviduct of R. dybowskii during pre-hibernation and the breeding period. There were significant differences in both oviductal weight and pipe diameter, with values markedly higher in pre-hibernation than in the breeding period. Histologically, epithelium cells, glandular cells and tubule lumen were identified in the oviduct during pre-hibernation and the breeding period, while sizes of both cell types are larger in the pre-hibernation than those of the breeding period. IL-1β was immunolocalized in the cytoplasm of epithelial and glandular cells in both periods, whereas IL-1R1 was observed in the membrane of epithelial and glandular cells in the breeding period, whereas only in epithelial cells during pre-hibernation. Consistently, the protein levels of IL-1β and IL-1R1 were higher in pre-hibernation as compared to the breeding period. These results suggested that IL-1β may play an important autocrine or paracrine role in oviductal cell proliferation and differentiation of R. dybowskii.

  4. Nueva especie de rana terrestre del género Pristimantis (Amphibia: Craugastoridae, meseta de la Dordillera del Cóndor

    Directory of Open Access Journals (Sweden)

    Jorge Brito M.

    2014-01-01

    Full Text Available Describimos una especie nueva, de mediano tamaño (LRC en la hembra 21.7-24.9 mm; en machos 15.2-17.8 mm, de rana terrestre del género Pristimantis proveniente de la meseta de arenisca de la Cordillera del Cóndor, del sureste de Ecuador, con una elevacion de 2300 m. La nueva especie difiere de sus congéneres presentes en Ecuador por su patrón distintivo de coloración, superficie dorsal pardo ocráceo con numerosas manchas amarillentas, membrana timpánica presente, dedos pediales y manuales cortos y microhábitat exclusivo en bromelias terrestres. Las llamadas son largas, de frecuencia modulada, conformada por 6-8 notas y un armónico. La descripción de Pristimantis paquishae sp. nov., es el resultado de un levantamiento de información de la herpetofauna, en una de las mesetas de arenisca remotas y menos conocidas, en la Cordillera del Cóndor.

  5. Extra-intestinal localization of Goussia sp. (Apicomplexa) oocysts in Rana dalmatina (Anura: Ranidae), and the fate of infection after metamorphosis.

    Science.gov (United States)

    Jirků, M; Modrý, D

    2006-06-23

    Although coccidia of the genus Goussia are common parasites of fish, only 2 species have been described in amphibians: G. hyperolisi from common reed frogs Hyperolius viridiflavus from Kenya and G. neglecta from unspecified European water frogs of the genus Rana from Germany. The genus Goussia is characterized by an oocyst, with a fine oocyst wall, containing 4 dizoic sporocysts that are composed of 2 valves joined by a longitudinal suture and lacking a Stieda body (typical for the genus Eimeria). To date, infections in amphibians were generally considered to be specific to the intestine of aquatic larval stages (tadpoles) of anurans. Herein, we report on: (1) the presence of oocysts of Goussia sp. in an extra-intestinal location (liver) of tadpoles of the agile frog R. dalmatina and (2) the presence of oocysts in the liver of both juvenile and subadult R. dalmatina. These observations represent novel traits for Goussia infections in amphibians; they may explain the vertical transmission of Goussia in tadpoles.

  6. River islands, refugia and genetic structuring in the endemic brown frog Rana kukunoris (Anura, Ranidae) of the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Zhou, Weiwei; Yan, Fang; Fu, Jinzhong; Wu, Shifang; Murphy, Robert W; Che, Jing; Zhang, Yaping

    2013-01-01

    Frequently, Pleistocene climatic cycling has been found to be the diver of genetic structuring in populations, even in areas that did not have continental ice sheets, such as on the Qinghai-Tibetan Plateau (QTP). Typically, species distributed on the plateau have been hypothesized to re-treat to south-eastern refugia, especially during the Last Glacial Maximum (LGM). We evaluated sequence variation in the mitochondrial DNA gene Cytb and the nuclear DNA gene RAG-1 in Rana kukunoris, a species endemic to the QTP. Two major lineages, N and S, were identified, and lineage N was further subdivided into N1 and N2. The geographical distribution and genealogical divergences supported the hypothesis of multiple refugia. However, major lineages and sublineages diverged prior to the LGM. Demographical expansion was detected only in lineage S and sublineage N2. Sublineage N1 might have survived several glacial cycles in situ and did not expand after the LGM because of the absence of suitable habitat; it survived in river islands. Genetic analysis and environment modelling suggested that the north-eastern edge of QTP contained a major refugium for R. kukunoris. From here, lineage S dispersed southwards after the LGM. Two microrefugia in northern Qilian Mountains greatly contributed to current level of intraspecific genetic diversity. These results were found to have important implications for the habitat conservation in Northwest China.

  7. 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.

  8. Ameliorative effects of sodium chloride on acute copper toxicity among Cope's gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos.

    Science.gov (United States)

    Brown, Maria G; Dobbs, Emily K; Snodgrass, Joel W; Ownby, David R

    2012-04-01

    Urban stormwater runoff is composed of a mixture of components, including polycyclic aromatic hydrocarbons, metals, deicing agents, and many others. The fate of these chemicals is often in stormwater detention ponds that are used by amphibians for breeding. Among aquatic organisms, the toxic mechanism for many metals involves interference with active Na(+) and Cl(-) uptake. Addition of cations has been shown to reduce the toxicity of metals among some aquatic organisms through competitive inhibition, but no studies have investigated the interaction between NaCl and Cu among amphibian embryos and larvae. To determine the degree to which NaCl may ameliorate the toxicity of Cu to amphibian embryos and larvae, the authors exposed Hyla chrysoscelis (Cope's gray treefrogs) and Rana (Lithobates) clamitans (green frogs) to seven levels of Cu and NaCl in fully factorial experiments. When exposure was in artificial hard water, Cu was highly toxic to both species (96-h median lethal concentration [LC50] of 44.7 µg/L and 162.6 µg/L for H. chrysoscelis and R. clamitans, respectively). However, approximately 500 mg/L of NaCl eliminated Cu toxicity over the range of Cu concentrations used in the experiments (maximum 150 µg Cu/L for H. chrysoscelis and 325 µg Cu/L for R. clamitans). The current results suggest that NaCl is likely responsible for the toxic effects of NaCl and metal mixtures that might be typical of runoff from road surfaces in northern latitudes.

  9. African-American Biography.

    Science.gov (United States)

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  10. Co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in Florida, USA

    National Research Council Canada - National Science Library

    Landsberg, Jan H; Kiryu, Yasunari; Tabuchi, Maki; Waltzek, Thomas B; Enge, Kevin M; Reintjes-Tolen, Sarah; Preston, Asa; Pessier, Allan P

    2013-01-01

    A multispecies amphibian larval mortality event, primarily affecting American bullfrogs Lithobates catesbeianus, was investigated during April 2011 at the Mike Roess Gold Head Branch State Park, Clay...

  11. Population declines lead to replicate patterns of internal range structure at the tips of the distribution of the California red-legged frog (Rana draytonii)

    Science.gov (United States)

    Richmond, Jonathan Q.; Backlin, Adam R.; Tatarian, Patricia J.; Solvesky, Ben G.; Fisher, Robert N.

    2014-01-01

    Demographic declines and increased isolation of peripheral populations of the threatened California red-legged frog (Rana draytonii) have led to the formation of internal range boundaries at opposite ends of the species’ distribution. While the population genetics of the southern internal boundary has been studied in some detail, similar information is lacking for the northern part of the range. In this study, we used microsatellite and mtDNA data to examine the genetic structuring and diversity of some of the last remaining R. draytonii populations in the northern Sierra Nevada, which collectively form the northern external range boundary. We compared these data to coastal populations in the San Francisco Bay Area, where the species is notably more abundant and still exists throughout much of its historic range. We show that ‘external’ Sierra Nevada populations have lower genetic diversity and are more differentiated from one another than their ‘internal’ Bay Area counterparts. This same pattern was mirrored across the distribution in California, where Sierra Nevada and Bay Area populations had lower allelic variability compared to those previously studied in coastal southern California. This genetic signature of northward range expansion was mirrored in the phylogeography of mtDNA haplotypes; northern Sierra Nevada haplotypes showed greater similarity to haplotypes from the south Coast Ranges than to the more geographically proximate populations in the Bay Area. These data cast new light on the geographic origins of Sierra Nevada R. draytonii populations and highlight the importance of distinguishing the genetic effects of contemporary demographic declines from underlying signatures of historic range expansion when addressing the most immediate threats to population persistence. Because there is no evidence of contemporary gene flow between any of the Sierra Nevada R. draytonii populations, we suggest that management activities should focus on

  12. Low levels of the herbicide atrazine alter sex ratios and reduce metamorphic success in Rana pipiens tadpoles raised in outdoor mesocosms.

    Science.gov (United States)

    Langlois, Valérie S; Carew, Amanda C; Pauli, Bruce D; Wade, Michael G; Cooke, Gerard M; Trudeau, Vance L

    2010-04-01

    There are conflicting reports regarding the effects of atrazine (ATZ) on amphibian development. Therefore, further studies are needed to examine the potential mechanisms of action of ATZ in amphibians. Our aim in this study was to determine whether low concentrations of ATZ affect gonadal development and metamorphosis in the Northern leopard frog, Rana pipiens. Tadpoles were exposed in outdoor mesocosms to nominal concentrations of 0.1 and 1.8 microg/L of formulated ATZ from Gosner stage 27 (G27) to metamorphic climax (G42). Exposure to 17alpha-ethinylestradiol (EE2; 1.5 microg/L) provided a positive control for induction of testicular oocytes in males. Endocrine-related gene expression and gonadal histopathology were examined at G42 and in a subset of premetamorphic G34 tadpoles that failed to metamorphose. Gonadal gross morphology revealed that the 1.8-microg/L ATZ treatment produced 20% more females compared with the control. Histologic analysis revealed that 22% of EE2-treated males had testicular oocytes, whereas none were observed in any animals from the control or either ATZ groups. ATZ increased brain estrogen receptor alpha mRNA to 2.5 times that of the control at premetamorphosis and altered liver levels of 5beta-reductase activity at metamorphosis. In contrast, brain aromatase mRNA level and activity did not change. ATZ treatments significantly reduced metamorphic success (number of animals reaching metamorphosis) without affecting body weight, snout-vent length, or age at metamorphosis. Gene expression analysis indicated that ATZ decreased the expression of deiodinase type 3 in the tail at premetamorphosis. Our study indicates that exposure to low concentrations of ATZ in experimental mesocosms alters gonadal differentiation and metamorphosis in developing R. pipiens.

  13. Una especie nueva de rana arbórea del género Hyloscirtus (Amphibia: Anura: Hylidae de la Cordillera del Cóndor

    Directory of Open Access Journals (Sweden)

    Ana Almendáriz

    2014-01-01

    Full Text Available Las ranas ecuatorianas del género Hyloscirtus incluyen 16 especies descritas, de las cuales 11 pertenecen al grupo H. larinopygion. Su distribución se limita a los flancos de la Cordillera de los Andes, tanto al oriente como al occidente. Una evaluación de la herpetofauna en el sector meridional de la Cordillera del Cóndor (bosques montanos sobre mesetas de arenisca en la provincia de Zamora Chinchipe, Ecuador, condujo al descubrimiento de una especie nueva del grupo que describimos aquí como Hyloscirtus condor sp. nov.; se analizan los renacuajos, las llamadas de anuncio y se estima las relaciones filogenéticas de la especie nueva y de las especies relacionadas en base a nuevas secuencias de los genes mitocondriales 12S, tRNA Val y 16S, con un total de hasta 2508 bp. Los resultados muestran que el grupo H. larinopygion está conformado por dos clados, uno distribuido en los Andes norte y centro de Ecuador y el otro al sur. La nueva especie pertenece al clado sur y es hermana de H. tapichalaca y de una especie aparentemente no descrita de la Provincia Morona Santiago. La especie nueva difiere de sus congéneres por su patrón de coloración dorsal, que consiste de puntos amarillo obscuro en un fondo canela. Es la especie más grande del grupo H. larinopygion y comparte con H. tapichalaca la presencia de una espina prepólica grande y curvada y brazos hipertrofiados. La especie nueva habita un área remota y bien conservada de la Cordillera del Cóndor. El descubrimiento de ésta y otras especies nuevas del mismo lugar denota la importancia biológica del área y motivan al desarrollo de planes de conservación.

  14. Evidence for directional selection at a novel major histocompatibility class I marker in wild common frogs (Rana temporaria exposed to a viral pathogen (Ranavirus.

    Directory of Open Access Journals (Sweden)

    Amber G F Teacher

    Full Text Available Whilst the Major Histocompatibility Complex (MHC is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria. Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago but before the Ranidae/Pipidae divergence (approximately 230 mya. We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry, and that the diseased populations have more similar supertype frequencies (lower F(ST than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year.

  15. Morphological and ultrastructural characteristics of Myxobolus ridibundae n. sp. (Myxosporea: Bivalvulida) infecting the testicular tissue of the marsh frog Rana ridibunda (Amphibia: Ranidae) in Egypt.

    Science.gov (United States)

    Abdel-Ghaffar, Fathy; Abdel-Gaber, Rewaida; Maher, Sherein; El Deeb, Nashwa; Kamel, Reem; Al Quraishy, Saleh; Mehlhorn, Heinz

    2017-01-01

    Myxozoans are one of the most economically important groups of protozoan parasites causing many serious diseases of their hosts. In the present study, a total of 60 live adult male specimens of the marsh frog Rana ridibunda have been randomly captured during the period of January-December 2015 in different areas at Kafr El-Sheikh Governorate, Egypt and were examined for infection by myxosporidian parasites. A total of 48 (80.0 %) out of 60 frog specimens were found to be infected with Myxobolus species. Parasitic infection was restricted to the testicular tissue of the examined frogs. Macroscopic cysts (plasmodia) which heavily infested different parts of the testes were recovered. Morphological and ultrastructural characteristics of these myxosporidian species were carried out using light and transmission electron microscopy. Plasmodia measured 0.16-0.53 (0.34 ± 0.01) mm in diameter. Mature spores appeared oval in frontal view, measuring 8.9-11.5 (9.6 ± 0.1) μm in length and 7.5-9.1 (8.4 ± 0.1) μm in width containing 5-6 turns of polar filaments. Morphometric characterization revealed that the very small size of the present Myxobolus species was the most distinctive feature that separates them from all previously described Myxobolus species. Ultrastructural analysis showed that the plasmodia are surrounded by a plasma membrane with numerous pinocytotic protrusions extending toward the host cell. The generative cells and the different developmental stages are arranged at the periphery of the plasmodia, while immature and mature spores are centrally located. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite are also described. The present species is described as Myxobolus ridibundae and represents a new species.

  16. Toward understanding the genetic basis of adaptation to high-elevation life in poikilothermic species: A comparative transcriptomic analysis of two ranid frogs, Rana chensinensis and R. kukunoris

    Directory of Open Access Journals (Sweden)

    Yang Weizhao

    2012-11-01

    Full Text Available Abstract Background Understanding how organisms adapt to high-elevation environments at a genome scale provides novel insights into the process of adaptive evolution. Previous studies have mainly focused on endothermic organisms, while poikilothermic species may have evolved different mechanisms to cope with high-elevation environments. In this context, we sequenced transcriptomes of a pair of closely related anuran species, Rana chensinensis and R. kukunoris, which inhabit respective low- and high-elevation habitats. By comparing the two transcriptomes, we identified candidate genes that may be involved in high-elevation adaption in poikilothermic species. Results Over 66 million sequence reads from each transcriptome were generated. A total of 41,858 and 39,293 transcripts for each species were obtained by de novo assembly. By comparing the orthologous transcripts, we identified 125 protein-coding genes that have likely experienced strong positive selection (Ka/Ks>1. In addition, 335 genes that may bear a signature of positive selection (1≥Ka/Ks>0.5 were also recognized. By considering their functions, fourteen candidate genes were determined to be likely involved in high-elevation adaptation, including two CYP genes, USP-1, and several others. Conclusions We identified a set of candidate genes that may have promoted adaptation of R. kukunoris to its high-elevation environment. These include several genes that have previously been associated with oxygen binding, response to UV radiation, and repair of free radical injury. Detailed molecular, physiological, and phenotypic studies are required to better understand the roles of these genes in improving the performance of R. kukunoris in a high-elevation environment. We have evidence for both convergent and divergent evolution between endothermic and poikilothemic species, but additional research across a wide range of organisms will be necessary to comprehend the complexity of high

  17. Effects of Evans Blue and amiloride on anti-diuretic hormone (ADH)-induced sodium transport across frog (Rana hexadactyla) skin.

    Science.gov (United States)

    Jared, Silviya Rajakumari; Rao, Jonakuty Prakasa

    2013-05-01

    The epithelial sodium channel (ENaC) has four subunits, namely α (alpha), β (beta), γ (gamma) and δ (delta). The functional ENaC is formed by the combination of either αβγ or δβγ subunits. The aim of the present study is to determine the combination of ENaC subunits predominant on the apical side of the frog skin, and the effect of ADH on sodium transport though these two ENaCs subunit combinations. The ventral abdominal skin of the frog, Rana hexadactyla was mounted in an Ussing-type chamber. The voltage-clamp method was performed to measure the ionic transport across the frog skin with normal Ringer solution (NR) on both sides. Evans blue (300 µM) and amiloride (100 µM) were added to the NR on the apical side and ADH (40 nM) was added on the serosal side. Statistical significance was analyzed by Student's paired t-test and repeated-measures ANOVA, P < 0.05 was considered significant. This study suggests that the ENaC of the frog skin consist of both αβγ and δβγ subunit combinations on the apical side. Though both types of subunit combination are present, the αβγ type was found to be more common than δβγ. ADH increases the sodium transport across the frog skin. The effect of ADH on sodium transport is achieved through the combination of δ-subunits, not through the combination of a-subunits in the skin of Pana hexadactyla.

  18. Don't get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations.

    Science.gov (United States)

    Sztatecsny, Marc; Preininger, Doris; Freudmann, Anita; Loretto, Matthias-Claudio; Maier, Franziska; Hödl, Walter

    2012-12-01

    Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1412-6) contains supplementary material, which is available to authorized users.

  19. Spatial Amphibian Impact Assessment – a management tool for assessment of road effects on regional populations of Moor frogs (Rana arvalis

    Directory of Open Access Journals (Sweden)

    Maj-Britt Pontoppidan

    2013-11-01

    a case study dedicated to the Moor frog (Rana arvalis.

  20. Enhancement of twitch force by stretch in a nerve-skeletal muscle preparation of the frog Rana porosa brevipoda and the effects of temperature on it.

    Science.gov (United States)

    Ishii, Yoshiki; Watari, Takashi; Tsuchiya, Teizo

    2004-12-01

    We investigated the mechanism of the enhancement of twitch force by stretch and the effects of temperature on it in nerve-skeletal muscle preparations of whole iliofibularis muscles isolated from the frog Rana brevipoda. When a preparation was stimulated indirectly and stretched, the twitch force after the stretch was enhanced remarkably in comparison to that observed before a stretch at low temperature. The enhanced force obtained by a stretch of 20% resting muscle length (l0) at low temperature was as high as the force obtained by direct stimulation. The phenomenon was not dependent on the velocity but on the amplitude of stretch. The enhanced force obeyed the length-force relationship when a stretch was long enough. The above results were observed when the frogs were kept at room temperature (20-22 degrees C). Measurements were also taken at low temperature (4 degrees C); when frogs were kept at low temperature for more than 2 months, twitch force obtained without stretch was considerably higher at l0. The amplitude of the action potential recorded extracellularly from the muscle surface increased remarkably after a stretch, but was same before and after a stretch when recorded from the nerve innervating muscle. The effects of temperature on twitch and tetanic force by direct or indirect stimulation without stretch were also studied as basic data of the stretch experiment. The results from this study suggest that stretch-induced force enhancement in a nerve-muscle preparation is caused by an increase in the transmission rate between nerve and muscle, and the amplitude of the enhanced force is determined by the length-force relationship of the muscle. The phenomenon is also strongly affected by the temperature at which the frogs are kept.

  1. 农药乐果对昭觉林蛙蝌蚪的耐受性研究%Tolerance of Dimethoate to Rana chaochiaoensis Tadpole

    Institute of Scientific and Technical Information of China (English)

    张庆; 郭兴焱; 李凤莲; 周伟

    2008-01-01

    采用水生生物急性毒性试验方法,研究乐果对昭觉林蛙Rana chaochiaoensis蝌蚪的急性毒性影响,同时运用扫描取样法对正式实验的昭觉林蛙蝌蚪进行行为观察.结果 表明:昭觉林蛙蝌蚪在试验组中正常静止行为、异常静止行为、正常运动行为、异常运动行为分别占74.08%、9.41%、0.58%、2.36%;在对照组中,只有正常静止行为和正常运动行为,分别占90.99% 和9.01%.乐果对昭觉林蛙蝌蚪24 h、48 h、72 h、96 h的半致死浓度 (LC50) 分别为:76.97 mg/L、67.85 mg/L、56.61 mg/L、52.80 mg/L,呈现出线性关系,安全浓度 (SC) 为5.28 mg/L.因此,乐果对昭觉林蛙蝌蚪当属于低毒性农药.但是当乐果残留量超过安全浓度时,将会影响昭觉林蛙蝌蚪的正常生长发育,并对其行为产生影响.

  2. Evidence for Directional Selection at a Novel Major Histocompatibility Class I Marker in Wild Common Frogs (Rana temporaria) Exposed to a Viral Pathogen (Ranavirus)

    Science.gov (United States)

    Teacher, Amber G. F.; Garner, Trenton W. J.; Nichols, Richard A.

    2009-01-01

    Whilst the Major Histocompatibility Complex (MHC) is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria). Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago) but before the Ranidae/Pipidae divergence (approximately 230 mya). We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus) with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry), and that the diseased populations have more similar supertype frequencies (lower FST) than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year. PMID:19240796

  3. Sialyl-glycoconjugates in cholesterol-rich microdomains of P388 cells are the triggers for apoptosis induced by Rana catesbeiana oocyte ribonuclease.

    Science.gov (United States)

    Ogawa, Y; Sugawara, S; Tatsuta, T; Hosono, M; Nitta, K; Fujii, Y; Kobayashi, H; Fujimura, T; Taka, H; Koide, Y; Hasan, I; Matsumoto, R; Yasumitsu, H; Kanaly, R A; Kawsar, S M A; Ozeki, Y

    2014-02-01

    SBL/RC-RNase was originally isolated from frog (Rana catesbeiana) oocytes and purified as a novel sialic acid-binding lectin (SBL) that displayed strong anti-cancer activity. SBL was later shown to be identical to a ribonuclease (RC-RNase) from oocytes of the same species. The administration of SBL/RC-RNase induced apoptosis (with nuclear condensation and DNA fragmentation) in mouse leukemia P388 cells but did not kill umbilical vein endothelial or fibroblast cells derived from normal tissues. The cytotoxic activity of SBL/RC-RNase was inhibited by desialylation of P388 cells and/or the co-presence of free bovine submaxillary mucin. FACS analysis showed that SBL/RC-RNase was incorporated into cells after attachment to cholesterol-rich microdomains. Addition of the cholesterol remover methyl-β-cyclodextrin reduced SBL/RC-RNase-induced apoptosis. Apoptosis occurred through the caspase-3 pathway following activation of caspase-8 by SBL/RC-RNase. A heat shock cognate protein (Hsc70) and a heat shock protein (Hsp70) (each 70 kDa) on the cell membrane were shown to bind to SBL/RC-RNase by mass spectrometric and flow cytometric analyses. Quercetin, an inhibitor of Hsc70 and Hsp70, significantly reduced SBL/RC-RNase-induced apoptosis. Taken together, our findings suggest that sialyl-glycoconjugates present in cholesterol-rich microdomains form complexes with Hsc70 or Hsp70 that act as triggers for SBL/RC-RNase to induce apoptosis through a pathway involving the activation of caspase-3 and caspase-8.

  4. The luteotrophic effect of homoplastic pituitary pars distalis homogenate, PMSG, and HCG on the corpora lutea of the hypophysectomized frog, Rana cyanophlyctis (SCHN).

    Science.gov (United States)

    Pancharatna, M; Saidapur, S K

    1984-03-01

    The effect of homoplastic pituitary pars distalis homogenate (PDH), PMSG, and HCG on the postovulatory follicles/corpora lutea (CL) of the frog Rana cyanophlyctis was studied to elucidate the factors regulating the life span of the luteal cells. Ovulation and spawning was induced in hypophysectomized frogs using PDH. Starting from Day 1 of spawning 1/2 PDH, 50 IU PMSG, or 50 IU HCG was injected daily for 3 days. In the saline-injected control frogs, the granulosa lutein cells regressed markedly on Day 2 with a steady progressive increase in the pycnosis of their nuclei. The sudanophilic lipid droplets of the luteal cells were fine on Day 1 but became coarser and reduced in number on subsequent days. Histochemically, the luteal cell 3 beta-HSDH and G-6-PDH also decreased drastically by Day 2. In PDH-treated frogs the granulosa lutein cells were healthy on all 4 days of the experiment. The nuclear diameter of the luteal cells increased progressively due to PDH. The pycnosis of the luteal cells was limited to 7.6% on Day 4 due to PDH as opposed to 68% seen in the controls. Histochemically, 3 beta-HSDH and G-6-PDH activities remained much higher than in the controls with abundant sudanophilic lipids (both fine and coarse) in the luteal cells of PDH treated frogs even on Day 4. PMSG treatment also maintained the granulosa lutein cells beyond their normal life span but the luteotrophic effect was less than that of PDH. HCG was least effective. The present studies suggest that the structural integrity of CL in the frog can be extended beyond the normal life span by injecting PDH or PMSG.

  5. Colonization of frog Rana temporaria L. urinary bladder by Gram-negative bacteria leads to decreased effect of arginine-vasotocin on water reabsorption from the urinary bladder.

    Science.gov (United States)

    Fock, Ekaterina; Lavrova, Elena; Parnova, Rimma

    2013-11-01

    In frogs and toads the urinary bladder is very important for the maintenance of water balance due to its ability to store water which can be reabsorbed under the action of arginine-vasotocin (AVT). The usage of isolated bladders as a model for studying the osmotic water permeability (OWP) regulation has a disadvantage which relates to high variability of AVT effect among individuals, some showing insensitivity to the hormone. We hypothesized that the response of the bladder to AVT could depend on the colonization of the mucosal epithelium by Gram-negative bacteria. To test this, paired hemibladders of the frog Rana temporaria were used for measurement of OWP and for analysis of Gram-negative bacteria in the bladder tissue or isolated epithelial cells. Among the 206 frogs studied, 41% were infected by different Enterobacteriaceae, with prevalence of Hafnia alvei and Escherichia coli. In infected bladders the basal level of OWP was unchanged, whereas OWP stimulated by AVT was reduced (non-infected: 2.53 ± 0.13, n = 59, infected: 1.21 ± 0.17 µL min(-1)  cm(-2), n = 38, for the 15 min of AVT action, P < 0.001). In the sample, 100% of hemibladders that responded to AVT very weakly (OWP <0.5 µL min(-1)  cm(-2)) had a bacterial infection. Overnight treatment of hemibladders with mucosal lipopolysaccharide E. coli decreased OWP induced by AVT, forskolin, or IBMX lowering basal and stimulated level of cAMP. The data obtained indicate that the frog bladder epithelium could be colonized by Gram-negative bacteria, probably of cloacal origin, leading to reduction of sensitivity to AVT and to impairment of the urinary bladder to provide osmoregulation. © 2013 Wiley Periodicals, Inc.

  6. Asthma and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Asthma Asthma and Hispanic Americans In 2014, 2.1 million Hispanics reported that they currently have asthma. Puerto Rican Americans have almost twice the asthma ...

  7. American Hospice Foundation

    Science.gov (United States)

    American Hospice Foundation Skip to content Home Caregiving Learning About Hospice Grief Grieving Children Grief at School Grief at ... for all who come after us. The American Hospice Foundation (AHF) closed its doors in June 2014. ...

  8. American Society of Echocardiography

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    American Society of Echocardiography Join Ase Member Portal Log In Membership Member Portal Log In Join ASE Renew Benefits Rates FASE – Fellow of the American Society of Echocardiography Member Referral Program FAQs Initiatives Advocacy ...

  9. American Urogynecologic Society

    Science.gov (United States)

    ... Patient Site » PFD Registry » Contact Us American Urogynecologic Society 1100 Wayne Avenue, Suite 670 Silver Spring, MD ... Us | Privacy Policy | HONcode Accredited © 2016 American Urogynecologic Society. All rights reserved.

  10. American Vitiligo Research Foundation

    Science.gov (United States)

    ... life can acquire vitiligo Welcome to The American Vitiligo Foundation 2017 AVRF Calendars Order your calendar with ... animal testing. Please Visit Our Donations Page American Vitiligo Research Foundation "We Walk By Faith, Not By ...

  11. Obesity and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Obesity Obesity and Hispanic Americans Among Mexican American women, 77 ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  12. Obesity and Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 05/25/2016] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  13. 中国林蛙两性异形及其与繁殖的适应%Sexual dimorphism adapted to reproduction in Rana chensinensis

    Institute of Scientific and Technical Information of China (English)

    宋涛; 王宏元; 张育辉

    2012-01-01

    Based on measuring 11 morphological characteristics of 60 female and 60 male adult frogs which were collected from the Qinling Mountains, China, the mechanism of sexual dimorphism of Rana chensinensis was studied. The results showed that the snout-vent length (SVL) (t=3.94, df=118, P(0. 001) and body mass of females(t=5.61, df=118, P〈0. 001) are larger than that of males. The ANCOVA analysis indicated that the head length, head width, internasal length, interocular length, eye diameter, tympanum diameter, fore-limb length and hind-limb length of males are significantly lager than that of females. The snout length(F1,118 = 2.76, P=0.84) for males is not differ between males and females. It is indicated by regression analysis that head length, head width, tympanum diameter and other characters of frogs positively correlate with SVL. A principal component analysis generated three components (with eigenvalue E≥1) from ten size-free morphological variables, accounting for 74. 308 % of variation in the original data. The first component (51. 539% variance explained) has high positive loading for size free values of head length, head width, internasal length, interocular length, fore-limb length and hind-limb length, the second component (14. 045%) for size free value of body mass, and the third component (8. 723%) for size free values of eye diameter, tympanum diameter. The results indicated that partial sexual dimorphism exists in Rana chensinenis, female clutch size and fecundity, and therefore reproductive success, typically increased with female body size. The other distinct morphological characteristics in males are relative to sexual selection.%通过对中国林蛙(Rana chensinensis)成体雌雄各60例样本的11项形态指标的测量,分析该物种的两性异形特征,探讨产生两性异形的机制.结果表明,雌性的体长(t=3.94,df=118,P〈0.001)和体重(t=5.61,df=118,P〈0.001)显著大于雄性;

  14. American Indian Recipes.

    Science.gov (United States)

    Gurnoe, Katherine J.; Skjervold, Christian, Ed.

    Presenting some 60 to 70 Native American recipes, this document includes a brief introduction and a suggested reading list (15 citations related to American Indian foods). The introduction identifies five regional Native American cuisines as follows: in the Southwest, peppers and beans were made into chili, soups, guacamole, and barbecue sauces by…

  15. Heart Disease and African Americans

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    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  16. Effects of Oviductus Ranae on Alcoholic Hepatic Fibrosis in Rats%林蛙油逆转大鼠酒精性肝纤维化的作用机制

    Institute of Scientific and Technical Information of China (English)

    许会静; 张磊; 郝峰; 王皓; 郭健; 李艳

    2015-01-01

    Objective To observe the effect of oviductus ranae on alcoholic liver fibrosis in rats. Methods The alcohol irrigation stomach method wine replication model of alcoholic liver fibrosis in rats,model group received the oviductus ranae and colchicine treatment,rat liver tissue were detected,pathological changes of rat liver were observed by transmission electron microscope. Results Transmission electron microscopy showed that most of the liver fibrosis tissues were transformed to normal tissues. Conclusion By inhibiting the activation of hepatic stel ate cel s and reverse the alcoholic liver fibrosis in rats.%目的:观察林蛙油对大鼠酒精性肝纤维化的作用。方法采用酒精灌胃的方法复制大鼠酒精性肝纤维化模型,将模型组给予林蛙油和秋水仙碱治疗,取大鼠肝组织进行检测,透射电镜观察大鼠肝脏病理学改变。结果透射电镜结果显示,林蛙油治疗后,大多肝纤维化组织向正常组织转化。结论林蛙油通过抑制肝星状细胞的活化逆转大鼠酒精性肝纤维化。

  17. USO DE MICROHÁBITAT, DIETA Y TIEMPO DE ACTIVIDAD EN CUATRO ESPECIES SIMPÁTRICAS DE RANAS HÍLIDAS NEOTROPICALES (ANURA: HYLIDAE

    Directory of Open Access Journals (Sweden)

    MUÑOZ-GUERRERO JAIDER

    2007-12-01

    Full Text Available Se estudiaron el uso del microhábitat, la dieta y la actividad reproductiva en cuatroespecies simpátricas de hílidos en charcas temporales del Caribe colombiano. Seregistraron ocho especies de hílidos pero sólo cuatro de ellas se estudiaron dada suabundancia y representatividad: Dendropsophus microcephalus, Scarthyla vigilans,Hypsiboas pugnax y Scinax rostratus. Durante la estación más seca del año no seencontraron ranas, así el tiempo de muestreo y las observaciones se hicieron durantelas estaciones de lluvias entre 1999 y 2001. El uso del microhábitat (sustrato y alturavarió entre las especies; las especies pequeñas D. microcephalus y S. vigilans seencontraron en el agua sobre vegetación emergente, mientras que las especies detamaños corporales mayores se hallaron en vegetación alta alrededor de los charcos(H. pugnax, S. rostratus; así, un solapamiento espacial es evidente sólo entreespecies de similar tamaño. No hubo diferencias entre especies en el tipo de presasconsumidas; sin embargo, hubo diferencias significativas en la frecuencia y el tamañode las presas ingeridas en relación con el tamaño corporal: a más grandes tamañoscorporales, mayores tamaños de presas consumidas. Durante las estaciones de lluvias,la abundancia y la actividad de canto de las cuatro especies no fueron continuasen el tiempo. Aunque los machos de las cuatro especies fueron reproductivamenteactivos todos los meses, las diferencias en el tiempo de actividad son dadas por eltiempo de actividad reproductiva de las hembras. S. vigilans y S. rostratus tienen unareproducción explosiva mientras que D. microcephalus y H. pugnax mostraron unareproducción extendida en el tiempo durante la mayor parte de la estación de lluvias.Así, se observó una segregación temporal entre las especies de tamaño corporalsimilar permitiendo un mínimo solapamiento en el uso de los recursos (alimento ymicrohábitat.

  18. Residues of polybrominated diphenyl ethers in frogs (Rana limnocharis) from a contaminated site, South China: tissue distribution, biomagnification, and maternal transfer.

    Science.gov (United States)

    Wu, Jiang-Ping; Luo, Xiao-Jun; Zhang, Ying; Chen, She-Jun; Mai, Bi-Xian; Guan, Yun-Tao; Yang, Zhong-Yi

    2009-07-15

    Environmental pollutants are suspected to be a cause of global declines in amphibian populations, but few data are available on the bioaccumulation of polybrominated diphenyl ethers (PBDEs) in amphibians. To examine the tissue distribution, biomagnification potential, and maternal transfer of PBDEs in frogs, eighteen PBDE congeners were measured in the muscle, liver, and egg tissues of rice frogs (Rana limnocharis) and insects collected from an electronic waste (e-waste) recycling site in South China. PBDE levels in the frogs ranged from 0.63 to 11.6, 4.57 to 56.2, and 10.7 to 125 ng/g wet wt in the muscles, livers, and eggs, respectively. The frogs exhibited a unique congener profile, compared to those in aquatic and terrestrial species, with BDEs 99, 153, 183, 209, and 47 as the dominant congeners, intermediating between aquatic and terrestrial species. Most of the PBDE congeners in general showed higher affinity to liver than to muscle tissue. Except for BDEs 28, 47, 66, 138, and 206, the average biomagnification factors (BMFs) for all PBDE congeners were greater than 1.0, providing clear evidence of their biomagnification from insects to frogs. A parabolic relationship between log BMFs and bromine atom numbers or log Kow of PBDEs was observed, with the maximum BMF values for PBDEs with 6 bromine atoms (or at a log K(ow) of approximately 8.0). Relatively higher levels of 3-MeO-BDE 47 were found in male frogs, suggesting that male frogs in the present study might have higher metabolic capacity for PBDEs compared to female frogs. The ratio of levels in egg/female liver, indicating mother-to-egg transfer capacity, increased with increasing bromine atom numbers up to 7 and then declined as the bromine atom numbers rose. This indicated that the physicochemical properties of the congeners (e.g., K(ow), molecular sizes, and structures), resulting in different affinities to transport proteins, might impact their maternal transfer in frogs.

  19. African Americans in mathematics

    CERN Document Server

    1997-01-01

    This volume contains research and expository papers by African-American mathematicians on issues related to their involvement in the mathematical sciences. Little is known, taught, or written about African-American mathematicians. Information is lacking on their past and present contributions and on the qualitative and quantitative nature of their existence in and distribution throughout mathematics. This lack of information leads to a number of questions that have to date remained unanswered. This volume provides details and pointers to help answer some of these questions. Features: Research articles by distinguished African-American mathematicians. Accomplishments of African-American researchers in the mathematical sciences. Articles that explore issues important to the African-American community and to the mathematics community as a whole. Inspiration for African-American students who wish to pursue advancement in the mathematical sciences.

  20. Close relationships between Asian American and European American college students.

    Science.gov (United States)

    Chen, C; Edwards, K; Young, B; Greenberger, E

    2001-02-01

    The authors examined attitudes and behaviors regarding close relationships between European and Asian Americans, with a particular emphasis on 5 major subgroups of Asian Americans (Chinese, Japanese, Korean, Vietnamese, and Filipino Americans). Participants were 218 Asian American college students and 171 European American college students attending a culturally diverse university. The European Americans did not differentiate among the various subgroups of Asian Americans. Their attitudes regarding close relationships were less positive toward Asian Americans than toward Mexican and African Americans, a finding contrary to the prediction of social exchange theory (H. Tajfel, 1975). In contrast to the European Americans' view of homogeneity among Asian Americans, the 5 major subgroups of Asian Americans expressed a distinctive hierarchy of social preference among themselves. Results are discussed in terms of their implications for future research on interethnic relations involving Asian Americans.

  1. Expression analysis and identification of antimicrobial peptide transcripts from six North American frog species

    Science.gov (United States)

    Robertson, Laura S.; Fellers, Gary M.; Marranca, Jamie Marie; Kleeman, Patrick M.

    2013-01-01

    Frogs secrete antimicrobial peptides onto their skin. We describe an assay to preserve and analyze antimicrobial peptide transcripts from field-collected skin secretions that will complement existing methods for peptide analysis. We collected skin secretions from 4 North American species in the field in California and 2 species in the laboratory. Most frogs appeared healthy after release; however, Rana boylii in the Sierra Nevada foothills, but not the Coast Range, showed signs of morbidity and 2 died after handling. The amount of total RNA extracted from skin secretions was higher in R. boylii and R. sierrae compared to R. draytonii, and much higher compared to Pseudacris regilla. Interspecies variation in amount of RNA extracted was not explained by size, but for P. regilla it depended upon collection site and date. RNA extracted from skin secretions from frogs handled with bare hands had poor quality compared to frogs handled with gloves or plastic bags. Thirty-four putative antimicrobial peptide precursor transcripts were identified. This study demonstrates that RNA extracted from skin secretions collected in the field is of high quality suitable for use in sequencing or quantitative PCR (qPCR). However, some species do not secrete profusely, resulting in very little extracted RNA. The ability to measure transcript abundance of antimicrobial peptides in field-collected skin secretions complements proteomic analyses and may provide insight into transcriptional mechanisms that could affect peptide abundance.

  2. African American Suicide

    Science.gov (United States)

    African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, 1,908 (80. ... rate of 9.23 per 100,000). The suicide rate for females was 1.99 per 100, ...

  3. The Japanese American Story.

    Science.gov (United States)

    Fukei, Budd

    This book presents a view of the Japanese American experience from the time of their immigration to this country in the 1800s to their acculturation into American society in the 1970s. Topics dealt with include the prejudice and mistrust experienced by the Japanese immigrants in this country, particularly their evacuation and internment in…

  4. American Studies in Transition

    DEFF Research Database (Denmark)

    Nye, David

    Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies.......Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies....

  5. Writing American Indian History

    Science.gov (United States)

    Noley, Grayson B.

    2008-01-01

    The purpose of this paper is to critique the manner in which history about American Indians has been written and propose a rationale for the rethinking of what we know about this subject. In particular, histories of education as regards the participation of American Indians is a subject that has been given scant attention over the years and when…

  6. Teaching American Indian Architecture.

    Science.gov (United States)

    Winchell, Dick

    1991-01-01

    Reviews "Native American Architecture," by Nabokov and Easton, an encyclopedic work that examines technology, climate, social structure, economics, religion, and history in relation to house design and the "meaning" of space among tribes of nine regions. Describes this book's use in a college course on Native American architecture. (SV)

  7. Teaching American Indian Architecture.

    Science.gov (United States)

    Winchell, Dick

    1991-01-01

    Reviews "Native American Architecture," by Nabokov and Easton, an encyclopedic work that examines technology, climate, social structure, economics, religion, and history in relation to house design and the "meaning" of space among tribes of nine regions. Describes this book's use in a college course on Native American architecture. (SV)

  8. Primer registro de una población asilvestrada de rana toro (Lithobates catesbeianus en la Provincia de Córdoba, Argentina: Notas sobre la biología de la especie

    Directory of Open Access Journals (Sweden)

    Akmentins, Mauricio S.

    2008-12-01

    Full Text Available En Argentina se ha constatado la presencia de poblaciones asilvestradas de Lithobates catesbeianus en las provincias de San Juan (Sanabria et al., 2005 y de Misiones (Pereyra et al., 2006. Las ranas toro pueden eliminar a los anfibios nativos directamente a través de predación o competencia por interferencia, o indirectamente por competencia por explotación, modificación del comportamiento, alteración del hábitat o introducción de enfermedades o parásitos (Boone et al., 2004. El presente trabajo se realizó en la localidad de Agua de las Piedras (30º48' 46,2"S; 64º12'57,9"O; 760 msnm, la cual se encuentra a 65 km al norte de la ciudad de Córdoba, provincia de Córdoba, Argentina.

  9. Effect of Low Temperature Stress on Enzyme Specific Activity of GP and PEPCK in Male Rana dybowskii%低温胁迫对东北林蛙雄性成体GP、PEPCK比活性的影响

    Institute of Scientific and Technical Information of China (English)

    李秀峰; 肖向红; 柴龙会; 张晶钰

    2012-01-01

    采用葡萄糖氧化酶-过氧化物酶法、蒽酮比色定糖法分别检测低温胁迫下东北林蛙血糖和肝糖原、肌糖原的含量,并通过6-磷酸葡萄糖脱氢酶偶联比色法、乳酸脱氢酶偶联比色法分别检测低温胁迫下东北林蛙肝脏、肌肉糖原磷酸化酶(Glycogen phosphorylase,GP)和肝脏、肾脏磷酸烯醇式丙酮酸羧激酶(PEPCK)的比活性,以探讨低温对东北林蛙GP、PEPCK比活性的影响。结果表明:随着环境温度降低,东北林蛙血糖水平逐步升高,糖原含量逐步降低,与对照组相比,各低温组血糖升高极显著(P〈0.01),而肝糖原和肌糖原含量降低极显著(P〈0.01);与对照组相比,0℃组、-1℃组肝脏、肌肉组织GP比活性升高极显著(P〈0.01),且肝脏、肾脏PEPCK比活性升高极显著(P〈0.01)。说明低温胁迫促使东北林蛙糖原含量降低,糖原分解和糖异生限速酶比活性升高,进而血糖含量升高,提示血糖作为抗冻保护剂在东北林蛙冬眠中发挥重要作用。%The present study was aimed to investigate effect of low temperature stress on the enzyme specific activity of GP and PEPCK of Rana dybowskii.The impact of low temperature on the glucose,liver glycogen,muscle glycogen content of Rana dybowskii was determined and the impact of low temperature on the activities of GP,PEPCK of Rana dybowskiiwas also tested.Results showed that glucose contents in 4 ℃,0 ℃ and-1 ℃ groups were significantly increased(P0.01) compared with those in 23 ℃ group.Glycogen,muscle glycogen contents in 4 ℃,0 ℃ and-1 ℃ groups were significantly decreased(P0.01) compared with those in 23 ℃ group.Liver and muscle GP activities in 0 ℃ and-1 ℃ groups were observably increased(P0.01) compared with those in 23 ℃ group.Liver and kidney PEPCK activities in 0 ℃ and-1 ℃ groups were observably higher(P0.01) than those in 23 ℃ group.These results suggested that glucose

  10. African-Americans and Alzheimer's

    Science.gov (United States)

    ... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

  11. Abundancia relativa y uso de microhábitat de la rana Geobatrachus walkeri (Anura: Strabomantidae en dos hábitats en Sierra Nevada de Santa Marta, Colombia

    Directory of Open Access Journals (Sweden)

    Vera Martínez Baños

    2011-06-01

    Full Text Available La rana Geobatrachus walkeri pertenece a un género monotípico y endémico del área de San Lorenzo, Sierra Nevada de Santa Marta, Colombia. La especie habita en el bosque secundario natural y en una plantación de pino (dominada por Pinus patula. Para comparar la abundancia relativa y el uso del microhábitat en estos dos hábitat y durante los períodos de máxima y mínima precipitación, se distribuyeron aleatoriamente 30 cuadrantes en cada bosque sobre los que se registraron el número de individuos y los microhábitats ocupados. Además se reconocieron otros aspectos de la historia natural mediante muestreo por encuentros casuales (VES, se incluye en los dos hábitats áreas no muestreadas por los cuadrantes. La mayor abundancia de ranas se obtuvo en la plantación de pino y durante la época de lluvias. El microhábitat más usado fue la hojarasca de pino. Geobatrachus walkeri es una especie exitosa en las plantaciones de pino, asociada permanentemente a su hojarasca en donde parece desarrollar todo su ciclo de vida. Las claras modificaciones derivadas de la introducción de las plantaciones de pino en el suelo y el agua, parecen no haber afectado la supervivencia y mantenimiento exitoso de esta especie categorizada como en peligro de extinción.

  12. 中国林蛙卵油对焦虑大鼠运动能力影响研究%Effects of China Rana Egg Oil on the Exercise Capacity of Anxious Rats

    Institute of Scientific and Technical Information of China (English)

    闫清伟; 田青

    2013-01-01

    目的:研究中国林蛙卵油对焦虑大鼠运动能力及体重摄食量的影响;方法:通过焦虑造模,对50只SD雄性大鼠进行随机分5组,即安静色油组、安静卵油组、模型色油组、模型卵油组、模型安定组,通过药物干预测定相应指标进行分析研究;结果:发现中国林蛙卵油可以明显提高大鼠运动能力,提高大鼠饮食量及体重;结论:中国林蛙卵油在抗疲劳及抗焦虑方面有积极作用.%Objective:To study the influence of the China Rana egg oil on exercise capacity and body weight and food intake of rats.Methods:with the model of anxiety,50 male SD rats were randomly divided into 5 groups,namely,quiet salad group,quiet egg oil group,model salad group,model egg oil group,model diazepam group,Determination and analysis corresponding indicators of drug intervention.Results:it was found that China Rana egg oil can markedly improve the exercise performance of rats and increase the amount of diet and weight.Conclusion:Chinese woodfrog egg oil has a positive role on anti fatigue and anti anxiety.

  13. 实验温度对牛蛙神经冲动产生和传导的影响%Effects of Experimental Temperature on Nerve Impulse Generation and Conduction in Bull Frog (Rana catesbeiana )

    Institute of Scientific and Technical Information of China (English)

    罗来高; 许雪峰; 吴义莲; 殷培峰

    2012-01-01

    We recorded the action potential range and conductive velocity of the nerve trunk of bull frog (Rana catesbeiana) at seven (5, 15, 25, 30, 33, 35 and 39℃) temperatures, respectively. The results showed that testing temperature significantly affected the nerve impulse generation and conduction. The variations of the action potential range and conductive velocity with experimental temperature were asynchronous. The action potential range increased as temperature from 5 to 30℃ and decreased dramatically at higher temperatures. However, the nerve impulse conductive velocity was apparently faster at 25, 30 and 33℃ than that at lower than 25℃ or higher than 33℃.%测定了牛蛙(Rana catesbeiana)离体坐骨神经干在5、15、25、30、33、35、39℃七个温度条件下的动作电位波幅和传导速度.结果表明:温度显著影响牛蛙神经干的动作电位幅度和传导速度,牛蛙神经干动作电位幅度和传导速度不随温度的改变而呈同步的变化.在5 - 30℃温度范围内,牛蛙神经干的动作电位幅度随温度升高而增大,30℃后显著下降,39℃时最低;25、30、33℃动作电位的传导速度相对较快,温度低于25℃或高于33℃,牛蛙神经干的传导速度均呈显著的下降趋势.

  14. The effects of low temperature on nerve impulse generation and conduction of bull frog (Rana catesbeiana)%牛蛙神经冲动产生和传导的低温效应

    Institute of Scientific and Technical Information of China (English)

    吴义莲; 许雪峰; 罗来高; 殷培峰

    2012-01-01

    The action potential range and the conductive velocity of the nerve trunk of bull frog ( Rana catesbeiana) were measured at nine time (0, 24, 48, 96, 120, 144, 168, 192 and 216 h) under two (5℃ and 15℃ ) temperatures. Results showed that there was no significant difference of the action potential range at 0 and 24 h under the two temperatures. The conductive velocity at 0 h under the relative high temperature (15℃ ) was greater than that under the lower temperature (5℃) , however, there was no difference of the conductive velocity between two temperatures at 24 h. The action potential range and the conductive velocity of the nerve trunk could not be examined at 48 h under 15℃ , whereas, they could maintain at a relative high level for one week under 5℃.%在5℃和15℃温度条件下,用牛蛙(Rana catesbeiana)离体坐骨神经标本测定0、24、48、96、120、144、168、192、216 h 9个时段的动作电位波幅和传导速度.结果表明:两个温度下离体坐骨神经的动作电位幅度在0 h和24 h差异均不显著,0 h时相对高温(15℃)下动作电位传导速度大于相对低温(5℃),24 h时两个温度下动作电位的传导速度差异不显著,相对高温下48 h时坐骨神经的兴奋性为零.相对低温条件下,坐骨神经兴奋性能维持7 d时间.

  15. 直链烷基苯磺酸钠对中国林蛙抗菌肽基因表达的影响%The Effects of Linear Alkylbenzene Sulfonate on Antimicrobial Peptide Genes Expression in Rana chensinensis

    Institute of Scientific and Technical Information of China (English)

    谢晖; 孙燕; 李治; 宋婧

    2011-01-01

    近年来由于生境丧失及环境污染等原因,中国林蛙野生种群急剧减少.为深入研究水体中普遍存在的阴离子表面活性剂直链烷基苯磺酸钠(linear alkylbenzene sulfonate,LAS)对中国林蛙生存的影响,通过急毒实验确定LAS对分别处于发育阶段26、32、42、46期的中国林蛙的半致死浓度.同时利用1、4、8 mg/L LAS处理不同发育阶段中国林蛙,研究LAS对中国林蛙存活率、发育状态的影响,并利用real-time PCR技术检测中国林蛙抗菌肽基因表达水平变化.结果表明,当处理时间为96 h,LAS浓度达到12.33 mg/L以上时会对不同发育阶段中国林蛙产生较为严重的致死效应.1~8 mg/L浓度范围的LAS虽然对中国林蛙存活和发育没有明显影响,但是改变了其抗菌肽基因表达模式.特别是中国林蛙胚后发育后期(32期)和变态期(42期),4~8 mg/L LAS会在不同程度上抑制prepropalustrin-2CE3 、preprobrevinin-2CE1和preprotemporin-1 CEd1抗菌肽基因表达.总体而言,高浓度LAS对中国林蛙免疫系统造成一定影响,可能使该物种更易受到致病菌的侵袭.研究结果为化学污染物对中国林蛙免疫系统影响积累了实验数据,同时为研究中国林蛙抗菌肽基因表达的调控通路提供一定的理论依据.%Rana chensinensis has been suffered from a dramatic reduction in recent years due to the losing of habitat, environmental pollution and so on. To understand the influence of linear alkylbenzene sulfonate (LAS), which is one of the most important pollutants in water environment, on the survival of Rana chensinensis, the median lethal concentration of LAS had been calculated by explosion of the frogs at stage 26, 32, 42, 46 in different concentrations of LAS. The effects of 1, 4, 8 mg/L LAS on the survival and development of Rana chensinensis at different stages were also investigated. Also, the expressions of antimicrobial peptide genes were detected by real-time PCR. The

  16. American Studies in Romania

    Directory of Open Access Journals (Sweden)

    Ioana Luca

    2006-01-01

    Full Text Available American Studies at the University of BucharestThe idea of teaching American Studies and founding a program in American Studies was first voiced in the long meetings of faculty and students held at the University of Bucharest soon after the collapse of the communist regime. The proposal was one of many that reflected the spirit of reform and hope for radical changes at the outset of Romania’s transition to democracy. The absence of institutional structures other than English departments and t...

  17. CHARACTERISTICS OF AMERICAN ENGLISH

    Institute of Scientific and Technical Information of China (English)

    韦娟; 黄舜

    2007-01-01

    The large scale colonization of America by British settlers took place in the seventeenth century.During the process,the immigrants brought English to America.They desert great influence to the development of American English.After the civil war,American got political independence,and then there arose a tendency to develop an American brand of English.Famous persons like Thomas Jeffe,Benjamin,Franklin,and Noah Webster began to consider that the country should have a language of its own.

  18. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica)

    Science.gov (United States)

    Al-attar, Rasha; Zhang, Yichi

    2017-01-01

    Background The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration-full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively). Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively). On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control) and kidney (1.1-fold). Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in dehydrated muscle, and by

  19. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Rasha Al-attar

    2017-01-01

    Full Text Available Background The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration-full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively. Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively. On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control and kidney (1.1-fold. Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in

  20. General American: An Ambiguity

    Science.gov (United States)

    Van Riper, William R.

    1973-01-01

    Disputes use of the term General American'' because of the excessive breadth of its scope and its indefiniteness; article is part of Lexicography and Dialect Geography, Festgabe for Hans Kurath''. (DD)