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Sample records for leopard frog rana

  1. EVIDENCE OF PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, AND ARIZONA

    EPA Science Inventory

    Remnant populations of leopard frogs within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada either represent the reportedly extinct taxon Rana onca or northern, disjunct Rana yavapaiensis. To determi...

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

    SciTech Connect

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

    1999-11-01

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

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

    USGS Publications Warehouse

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

    2009-01-01

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

  4. POPULATION STATUS AND DISTRIBUTION OF A DECIMATED AMPHIBIAN, THE RELICT LEOPARD FROG (RANA ONCA)

    EPA Science Inventory

    The relict leopard frog (Rana onca) was once thought to be extinct, but has recently been shown to comprise a valid taxon with extant populations. We delineate the minimum historical range of the species, and report results of surveys at 12 historical and 54 other localities to d...

  5. EVIDENCE FOR PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, ARIZONA

    EPA Science Inventory


    Remnant populations of leopard frogs exist within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada. These populations either represent the reportedly extinct taxa Rana onca or northern, disjunct R...

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

    EPA Science Inventory

    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...

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

    USGS Publications Warehouse

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

    2008-01-01

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

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

    USGS Publications Warehouse

    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.

  9. Photoinduced toxicity of fluoranthene to northern leopard frogs (Rana pipiens)

    SciTech Connect

    Monson, P.D.; Call, D.J.; Cox, D.A.; Liber, K.; Ankley, G.T.

    1999-02-01

    Rana pipiens larvae were exposed for 48 h in a flow-through system to clean water or five concentrations of the phototoxic polycyclic aromatic hydrocarbon (PAH) fluoranthene. Following this uptake period, the larvae were divided into four groups: one for immediate tissue residue analysis, a second for residue analysis following 48 h of depuration in clean water, and two for a 48-h exposure in clean water to ultraviolet (UV) light at two different levels. At the highest treatment, mean intensity was 8.12 {+-} 0.19 {times} 10{sup 2} {micro}W/cm{sup 2}, whereas at a lower treatment the UVA intensity was 4.45 {+-} 0.05 {times} 10{sup 2} {micro}W/cm{sup 2}. Larval frogs bioaccumulated fluoranthene in direct proportion to the water exposure concentrations, with initial whole-body PAH concentrations of 1.48, 3.53, 4.85, 11.3, and 18.7 {micro}g/g at the five treatment levels. No mortality of the animals occurred during the 48-h uptake phase. When the frogs were placed in clean water, the fluoranthene was rapidly depurated, with up to 80% lost in 48 h. Exposure to UV light following fluoranthene exposure significantly enhanced toxicity of the PAH. Median time to death decreased as the product of UVA light intensity and fluoranthene body residue increased. For larval R. Pipiens, sufficient tissue residues of fluoranthene were bioaccumulated within 48 h, at water exposure concentrations in the range of 2 to 10 {micro}g/L, to be lethal when combined with a UVA exposure simulating a fraction of summertime, midday sunlight in northern latitudes.

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

    PubMed

    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.

  11. Haematoloechus sp. infection in wild-caught northern leopard frogs (Rana pipiens).

    PubMed

    Hsu, Charlie; Carter, D Bart; Williams, Donna; Besch-Williford, Cynthia

    2004-11-01

    Three male, wild-caught northern leopard frogs (Rana pipiens) died over a 1-week period with no previous history of clinical illness or disease. Noteworthy necropsy findings in one of the three frogs included depleted fat bodies in the coelomic cavity, indicating a poor nutritional condition, and a heavy parasite burden in the lungs. The location of infection and morphologic characteristics of the parasite were consistent with infection by the common lung fluke, Haematoloechus sp. In contrast to the heavy fluke load, only minor microscopic changes were observed in the lungs. Lesions included mild hypertrophy of the bronchiolar epithelium, with few submucosal inflammatory cells consisting predominantly of lymphocytes. Subsequent review of the literature revealed little about the pathologic effects of these parasites except that small numbers are thought to cause the host little harm. Our findings suggest that even with a large number of parasites, there is minimal pathologic impact in the lungs. We conclude that heavy lung-fluke infection should not be diagnosed as the sole or major etiology of death or illness in leopard frogs.

  12. Evaluation of metomidate hydrochloride as an anesthetic in leopard frogs (Rana pipiens).

    PubMed

    Doss, Grayson A; Nevarez, Javier G; Fowlkes, Natalie; da Cunha, Anderson F

    2014-03-01

    Metomidate hydrochloride is an imidazole-based, nonbarbiturate hypnotic drug primarily used as an immersion sedation and anesthetic agent in freshwater and marine finfish. To the authors' knowledge, there is no documentation in the literature of its use in amphibians. In this study, 7 male and 4 female leopard frogs (Rana pipiens) were induced with metomidate hydrochloride via immersion bath at a concentration of 30 mg/L for 60 min. The pH of the induction solution ranged from 7.63 to 7.75. Each frog was then removed from the induction solution, rinsed, and recovered in 26.6 degrees C amphibian Ringer's solution. After 210 min in the Ringer's solution, the frogs were transferred to moist paper towels for recovery. Heart rate, gular and abdominal respiration rates, righting reflex, superficial and deep pain withdrawal reflexes, corneal and palpebral reflexes, and escape response were monitored and recorded at defined intervals during both induction and recovery. The average time to loss of righting reflex and escape response was 17.36 min and 17.82 min, respectively. Metomidate produced clinical sedation in all frogs (n = 11). Surgical anesthesia was achieved in only 27% (3/11), with an anesthetic duration that ranged from 9 to 20 min. Recovery times were extremely prolonged and varied, with a range from 313 min to longer than 600 min. The findings of this study indicate that metomidate hydrochloride is unsuitable as a sole anesthetic agent in leopard frogs, and further research is needed to evaluate its suitability in other amphibians.

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

    USGS Publications Warehouse

    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

  14. Patterns of infection by lungworms, Rhabdias ranae and Haematoloechus spp., in northern leopard frogs: a relationship between sex and parasitism.

    PubMed

    Dare, Oluwayemisi K; Forbes, Mark R

    2009-04-01

    We examined a population of northern leopard frogs to determine whether sex biases in investment in immunity, previously reported for this host species under controlled exposures to lung nematodes, is predictive of patterns of parasitism in nature. We examined Rhabdias ranae and Haematoloechus spp. infections in 74 breeding adult, 28 non-breeding adult, and 53 juvenile frogs. Contrary to our predictions, R. ranae prevalence and mean abundance were higher in breeding female frogs (prevalence: 39.4%, abundance: 3.05 +/- 0.85) than on breeding males (prevalence: 26.0%, abundance: 1.17 +/- 0.52), although no sex bias was observed among non-breeding adults or juvenile frogs. Female frogs also carried larger R. ranae worms, on average, than did males (females: 6407.38 microm +/- 153.80; males: 5198 microm +/- 131.09), regardless of age or breeding condition. We observed no sex-linked patterns of parasitism by Haematoloechus spp. worms in either adult or juvenile frogs. Alternative hypotheses, such as differences among sexes in the selection of thermal clines for hibernation, may explain the observed female bias in parasitism by nematode lungworms in nature and, thus, need to be considered.

  15. Potential endocrine disruption of sexual development in free ranging male northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) from areas of intensive row crop agriculture.

    PubMed

    McDaniel, Tana V; Martin, Pamela A; Struger, John; Sherry, Jim; Marvin, Chris H; McMaster, Mark E; Clarence, Stacey; Tetreault, Gerald

    2008-07-30

    Intensive row crop agriculture (IRCA) for corn and soybean production is predominant in eastern and central North America. IRCA relies heavily on pesticide and nutrient inputs to maximize production under conventional systems. In 2003-2005, we assessed the occurrence of a suite of potential endocrine effects in amphibians inhabiting farm ponds and agricultural drains in IRCA areas of southwestern Ontario. Effects were compared to amphibians from two agricultural reference sites as well as four non-agricultural reference sites. Pesticide and nutrient concentrations were also determined in water samples from those sites. Atrazine and metolachlor were detected in most samples, exceeding 1 microg L(-1) at some sites. Blood samples were taken from northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) for analysis of circulating sex steroids and vitellogenin-like protein (Vtg-lp), a biomarker of exposure to environmental estrogens. Gonads were histologically examined for evidence of abnormalities. Some evidence of exposure to endocrine disrupting compounds was apparent from the data. The occurrence of testicular ovarian follicles (TOFS) in male R. pipiens was significantly higher (42%; p<0.05) at agricultural sites, particularly those in Chatham county compared to frogs from reference sites (7%). There was no difference in circulating sex steroid levels between frogs from agricultural and reference sites and sex steroid levels did not correlate with pesticide concentrations in the environment. No differences were detected in the gonadosomatic indices or stage of spermatogenesis between frogs from agricultural and non-agricultural regions (p>0.05). Plasma Vtg-lp was detected in only one male R. pipiens from an agricultural site. Neither gonad size, gonad maturity nor sex steroid levels differed between normal males and those with testicular oocytes. Although the proportion of testicular oocytes did not correlate directly with atrazine concentrations, it

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

    USGS Publications Warehouse

    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. Temporal occurrence and community structure of helminth parasites in southern leopard frogs, Rana sphenocephala, from north central Oklahoma.

    PubMed

    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

  18. Exposure of leopard frogs to a pesticide mixture affects life history characteristics of the lungworm Rhabdias ranae.

    PubMed

    Gendron, A D; Marcogliese, D J; Barbeau, S; Christin, M-S; Brousseau, P; Ruby, S; Cyr, D; Fournier, M

    2003-05-01

    We tested the hypothesis that exposure of leopard frogs ( Rana pipiens) to agricultural pesticides can affect the infection dynamics of a common parasite of ranid frogs, the lungworm Rhabdias ranae. After a 21-day exposure to sublethal concentrations of a pesticide mixture composed of atrazine, metribuzin, aldicarb, endosulfan, lindane and dieldrin, or to control solutions (water, dimethyl sulfoxide), parasite-free juvenile frogs were challenged with 30 infective larvae of R. ranae. Approximately 75% of the larvae penetrated the skin and survived in both exposed and control animals, suggesting that pesticides did not influence host recognition or penetration components of the transmission process. Rather, we found that the migration of R. ranae was significantly accelerated in hosts exposed to the highest concentrations of pesticides, leading to the establishment of twice as many adult worms in the lungs of frogs 21 days post-infection. Pesticide treatment did not influence the growth of lungworms but our results indicate that they matured and reproduced earlier in pesticide-exposed frogs compared to control animals. Such alterations in life history characteristics that enhance parasite transmission may lead to an increase in virulence. Supporting evidence shows that certain components of the frog immune response were significantly suppressed after exposure to the pesticide mixture. This suggests that the immune system of anurans exerts a control over lungworm migration and maturation and that agricultural contaminants can interfere with these control mechanisms. Our results also contribute to the ongoing debate regarding the role that anthropogenic factors could play in the perplexing disease-related die-offs of amphibians observed in several parts of the world.

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

    USGS Publications Warehouse

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  20. STATUS OF THE RELICT LEOPARD FROG (RANA ONCA): OUR LIMITED UNDERSTANDING OF THE DISTRIBUTION, SIZE, AND DYNAMICS OF EXTANT AND RECENTLY EXTINCT POPULATIONS

    EPA Science Inventory

    The relict leopard frog (Rana onca) was once thought to be extinct, but has recently been shown to comprise a valid taxon with extant populations. Here, we discuss research from several studies, conducted between 1991 and 200 1, that represent the basis for our understanding of t...

  1. Extinction of montane populations of the northern leopard frog (Rana pippins) in Colorado

    USGS Publications Warehouse

    Corn, Paul Stephen; Fogleman, James C.

    1984-01-01

    Between 1973 and 1982 nine populations of the northern leopard frog in the Red Feather Lakes region of Larimer County, Colorado, failed in reproduce. These failures all resulted in extinction of the populations. One area formerly supporting a population was recolonized in 1980, but no frogs were observed at any of the nine sites in 1981 or 1982. Six of the populations went extinct because the breeding ponds dried up. The remaining populations were small enough to be susceptible to random events, but the nature of these events is unknown.

  2. Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs (Rana pipiens): laboratory and field evidence.

    PubMed Central

    Hayes, Tyrone; Haston, Kelly; Tsui, Mable; Hoang, Anhthu; Haeffele, Cathryn; Vonk, Aaron

    2003-01-01

    Atrazine is the most commonly used herbicide in the United States and probably the world. Atrazine contamination is widespread and can be present in excess of 1.0 ppb even in precipitation and in areas where it is not used. In the current study, we showed that atrazine exposure (> or = to 0.1 ppb) resulted in retarded gonadal development (gonadal dysgenesis) and testicular oogenesis (hermaphroditism) in leopard frogs (Rana pipiens). Slower developing males even experienced oocyte growth (vitellogenesis). Furthermore, we observed gonadal dysgenesis and hermaphroditism in animals collected from atrazine-contaminated sites across the United States. These coordinated laboratory and field studies revealed the potential biological impact of atrazine contamination in the environment. Combined with reported similar effects in Xenopus laevis, the current data raise concern about the effects of atrazine on amphibians in general and the potential role of atrazine and other endocrine-disrupting pesticides in amphibian declines. PMID:12676617

  3. 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.

    PubMed

    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

  4. Vitellogenic cycles in laboratory-maintained females of the leopard frog, Rana pipiens.

    PubMed

    Smalley, K N; Nace, G W

    1983-05-01

    As a part of studies on the reproduction of laboratory maintained frogs, wild-caught Rana pipiens were ovulated and maintained at 22-27 degrees C for up to 18 months. Vitellogenic oocytes were periodically staged and counted, and a "maturity index" was calculated to assess the progress of the vitellogenic cycle. The initial cycle was similar to that of wild frogs except that the first oocytes to reach stage 5 (mature eggs) usually began to degenerate before later starting oocytes became mature. In addition, a second cycle began before the first was completed. After more than 1 year at room temperature, abnormal cycles were common. Ovaries of such animals contained very few mature eggs. Many of their oocytes were in early stages of vitellogenesis or, if pigmented, had begun to degenerate. These deficiencies were partially corrected in females placed in 4 degrees C for 4-6 weeks. The average number of mature eggs increased 15-fold and ovary weights more than doubled. Oviduct weights almost doubled. Although the rates of cooling, photoperiod, and nutritional status could be important influences, the results imply that cold treatment alone increases estrogen secretion. We suggest that low estrogen secretion may account for the reproductive deficiencies seen in R. pipiens cultured at room temperature.

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

    EPA Science Inventory

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

  6. Growth and developmental effects of coal combustion residues on Southern Leopard Frog (Rana sphenocephala) tadpoles exposed throughout metamorphosis

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2008-09-15

    The effects of aquatic deposition of coal combustion residues (CCRs) on amphibian life histories have been the focus of many recent studies. In summer 2005, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate (approximately 1 cm deep within plastic bins) and documented effects of sediment type on oral disc condition, as well as time to, mass at, and total body length at key developmental stages, including metamorphosis (Gosner stages (GS) 37, 42, and 46). We found no significant difference in mortality between the two treatments and mortality was relatively low (eight of 48 in the control group and four of 48 in the CCR group). Ninety percent of exposed tadpoles displayed oral disc abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR-contaminated sediment had decreased developmental rates and weighed significantly less at all developmental stages, on average, when compared to controls. The CCR treatment group was also significantly shorter In length than controls at the completion of metamorphosis (GS 46). Collectively, these findings are the most severe sub-lethal effects noted for any amphibian exposed to CCRs to date. More research is needed to understand how these long term effects may contribute to the dynamics of local amphibian populations.

  7. Genetic variation in insecticide tolerance in a population of southern leopard frogs (Rana sphenocephala): Implications for amphibian conservation

    USGS Publications Warehouse

    Bridges, C.M.; Semlitsch, R.D.

    2001-01-01

    Currently, conservation efforts are devoted to determining the extent and the causes of the decline of many amphibian species worldwide. Human impacts frequently degrade amphibian habitat and have been implicated in many declines. Because genetic variance is critical in determining the persistence of a species in a changing environment, we examined the amount of genetic variability present in a single population for tolerance to an environmental stressor. We examined the amount of genetic variability among full- and half-sib families in a single population of southern leopard frogs (Rana sphenocephala) with respect to their tolerance to lethal concentrations of the agricultural chemical, carbaryl. Analysis of time-to-death data indicated significant differences among full-sib families and suggests a large amount of variability present in the responses to this environmental stressor. Significant differences in responses among half-sib families indicated that there is additive genetic variance. These data suggest that this population may have the ability to adapt to environmental stressors. It is possible that declines of amphibian populations in the western United States may be attributed to low genetic variability resulting from limited migration among populations and small population sizes.

  8. Long-term effects of pesticide exposure at various life stages of the southern leopard frog (Rana sphenocephala)

    USGS Publications Warehouse

    Bridges, C.M.

    2000-01-01

    Amphibian larvae are commonly exposed to low levels of pesticides during their development. Chronic studies generally examine the effects of long-term exposure, but they often disregard the importance of the individual life stage at which tadpoles are exposed. I determined the point during development at which carbaryl effects are manifested by exposing southern leopard frog tadpoles (Rana sphenocephala) to the pesticide carbaryl at five different times during development. Metamorphs exposed throughout the tadpole stage and throughout development (egg, embryo, tadpole) experienced significant mortality at all chemical levels. Although the length of the larval period was the same for all experimental groups, metamorphs exposed during the egg stage were smaller than their corresponding controls, independent of whether they were exposed at any other stage. Nearly 18% of individuals exposed to carbaryl during development exhibited some type of developmental deformity (including both visceral and limb malformities), compared to a single deformed (< 1%) control tadpole, demonstrating that a chemical hypothesis for amphibian deformities remains viable. Because exposure to nonpersistent chemicals may last for only a short period of time, it is important to examine the long-term effects that short-term exposure has on larval amphibians and the existence of any sensitive life stage. Any delay in metamorphosis or decrease in size at metamorphosis can impact demographic processes of the population, potentially leading to declines or local extinction.

  9. PHYLOGEOGRAPHY OF RANA YAVAPAIENSIS AND RANA ONCA: PRELIMINARY FINDINGS WITH CONSERVATION IMPLICATIONS

    EPA Science Inventory

    The closely related aridland frogs Rana onca (Relict Leopard Frog) and Rana yavapaiensis (Lowland Leopard Frog) have both experienced dramatic population declines. Rana onca currently occurs naturally at only 6 disjunct sites in southern Nevada. Rana yavapaiensis is present acros...

  10. Cryptic invasion of Northern Leopard Frogs (Rana pipiens) across phylogeographic boundaries and a dilemma for conservation of a declining amphibian

    USGS Publications Warehouse

    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.

  11. PHOTOINDUCED TOXICITY OF FLUORANTHENE TO LARVAE OF THE LEOPARD FROG (RANA PIPENS)

    EPA Science Inventory

    Rana pipiens larvae (96-118 hr old) were exposed to in a flow-through diluter system to five concentrations of fluoranthene for 48 hr. Following the uptake period the exposed larvae were divided into three groups: one for tissue residue analysis, a second for residue analysis fo...

  12. Octylphenol and UV-B radiation alter larval development and hypothalamic gene expression in the leopard frog (Rana pipiens).

    PubMed Central

    Crump, Douglas; Lean, David; Trudeau, Vance L

    2002-01-01

    We assessed octylphenol (OP), an estrogenic endocrine-disrupting chemical, and UV-B radiation, a known stressor in amphibian development, for their effects on hypothalamic gene expression and premetamorphic development in the leopard frog Rana pipiens. Newly hatched tadpoles were exposed for 10 days to OP alone at two different dose levels; to subambient UV-B radiation alone; and to two combinations of OP and UV-B. Control animals were exposed to ethanol vehicle (0.01%) exposure, a subset of tadpoles from each treatment group was raised to metamorphosis to assess differences in body weight and time required for hindlimb emergence. Tadpoles from one of the OP/UV-B combination groups had greater body weight and earlier hindlimb emergence (p < 0.05), but neither OP nor UV-B alone produced significant changes in body weight or hindlimb emergence, indicating a potential mechanism of interaction between OP and UV-B. We hypothesized that the developing hypothalamus might be a potential environmental sensor for neurotoxicologic studies because of its role in the endocrine control of metamorphosis. We used a differential display strategy to identify candidate genes differentially expressed in the hypothalamic region of the exposed tadpoles. Homology cloning was performed to obtain R. pipiens glutamate decarboxylases--GAD65 and GAD67, enzymes involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA). cDNA expression profiles revealed that OP and UV-B affected the levels of several candidate transcripts in tadpole (i.e., Nck, Ash, and phospholipase C gamma-binding protein 4 and brain angiogenesis inhibitor-3) and metamorph (i.e., GAD67, cytochrome C oxidase, and brain angiogenesis inhibitor-2 and -3) brains. This study represents a novel approach in toxicology that combines physiologic and molecular end points and indicates that levels of OP commonly found in the environment and subambient levels of UV-B alter the expression of important hypothalamic

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

    SciTech Connect

    Williams, J.J.; Wofford, H.W.

    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.

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

    USGS Publications Warehouse

    Corn, Paul Stephen; Livo, Lauren J.

    1989-01-01

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

  15. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3{prime},4,4{prime},5-pentachlorobiphenyl

    SciTech Connect

    Huang, Y.; Jung, R.E.; Karasov, W.H.; Melancon, M.J.

    1998-08-01

    In the past decade, biochemical and physiological characteristics such as hepatic detoxifying system. DNA adducts, thyroid malfunction, and acetylcholinesterase inhibition have been used extensively as biomarkers for contaminant exposure. Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 m corn oil at a concentration of 0.2, 0.7, 2.3, or 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 {le}0.7 mg/kg (p > 0.05) but were significantly increased at doses {ge}2.3 mg/kg compared to the control groups (p < 0.05). The increased activities of these four enzymes were 3 to 6.4 times those in the control groups. The increased activities were maintained for at least 4 weeks. Because of a lack of induction at low doses of PCB 126, which were still relatively high compared to currently known environmental concentration, the authors suspect that EROD, MROD, BROD, and PROD activities are not sensitive biomarkers for coplanar PCB exposure in leopard frogs.

  16. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3',4,4',5-pentachlorobiphenyl

    USGS Publications Warehouse

    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 < 0.05). The increased activity of these four enzymes ranged from 3to 6.4fold relative to control levels. The increased activities were maintained for at least four weeks. Due to a lack of induction at low doses of PCB 126, which were still relatively high compared to currentlyknown environmental concentrations, we suspect that EROD, MROD, BROD, and PROD activities are not sensitive biomarkers for coplanar PCB exposure in leopard frogs.

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

    PubMed

    Lehman, G C

    1978-12-01

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

  18. 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

    USGS Publications Warehouse

    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.

  19. Impacts of agriculture on the parasite communities of northern leopard frogs (Rana pipiens) in southern Quebec, Canada.

    PubMed

    King, K C; McLaughlin, J D; Gendron, A D; Pauli, B D; Giroux, I; Rondeau, B; Boily, M; Juneau, P; Marcogliese, D J

    2007-12-01

    Given that numerous amphibians are suffering population declines, it is becoming increasingly important to examine the relationship between disease and environmental disturbance. Indeed, while many studies relate anthropogenic activity to changes in the parasitism of snails and fishes, little is known of the impact on the parasites of amphibians, particularly from agriculture. For 2 years, the parasite communities of metamorphic northern leopard frogs from 7 agricultural wetlands were compared with those from 2 reference wetlands to study differences in parasite community diversity and abundance of various species under pristine conditions and 3 categories of disturbance: only agricultural landscape, only pesticides, and agricultural landscape with pesticides. Agricultural (and urban) area was negatively related to species richness, and associated with the near absence of adult parasites and species that infect birds or mammals. We suggest that agriculture and urbanization may hinder parasite transmission to frogs by limiting access of other vertebrate hosts of their parasites to wetlands. The only parasite found at all localities was an unidentified echinostome infecting the kidneys. This parasite dominated communities in localities surrounded by the most agricultural land, suggesting generalist parasites may persist in disrupted habitats. Community composition was associated with dissolved organic carbon and conductivity, but few links were found with pesticides. Pollution effects may be masked by a strong impact of land use on parasite transmission.

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

    EPA Science Inventory

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

  1. The Classroom Animal: The Leopard Frog.

    ERIC Educational Resources Information Center

    Science and Children, 1985

    1985-01-01

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

  2. Semi-automated identification of leopard frogs

    USGS Publications Warehouse

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

    2014-01-01

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

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

    SciTech Connect

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

    1995-12-31

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

  4. A new species of leopard frog (Anura: Ranidae) from the urban northeastern US

    PubMed Central

    Newman, Catherine E.; Feinberg, Jeremy A.; Rissler, Leslie J.; Burger, Joanna; Shaffer, H. Bradley

    2014-01-01

    Past confusion about leopard frog (genus Rana) species composition in the Tri-State area of the US that includes New York (NY), New Jersey (NJ), and Connecticut (CT) has hindered conservation and management efforts, especially where populations are declining or imperiled. We use nuclear and mitochondrial genetic data to clarify the identification and distribution of leopard frog species in this region. We focus on four problematic frog populations of uncertain species affiliation in northern NJ, southeastern mainland NY, and Staten Island to test the following hypotheses: (1) they are conspecific with Rana sphenocephala or R. pipiens, (2) they are hybrids between R. sphenocephala and R. pipiens, or (3) they represent one or more previously undescribed cryptic taxa. Bayesian phylogenetic and cluster analyses revealed that the four unknown populations collectively form a novel genetic lineage, which represents a previously undescribed cryptic leopard frog species, Rana sp. nov. Statistical support for R. sp. nov. was strong in both the Bayesian (pp = 1.0) and maximum-likelihood (bootstrap = 99) phylogenetic analyses as well as the Structure cluster analyses. While our data support recognition of R. sp. nov. as a novel species, we recommend further study including fine-scaled sampling and ecological, behavioral, call, and morphological analyses before it is formally described. PMID:22321689

  5. A new species of leopard frog (Anura: Ranidae) from the urban northeastern US.

    PubMed

    Newman, Catherine E; Feinberg, Jeremy A; Rissler, Leslie J; Burger, Joanna; Shaffer, H Bradley

    2012-05-01

    Past confusion about leopard frog (genus Rana) species composition in the Tri-State area of the US that includes New York (NY), New Jersey (NJ), and Connecticut (CT) has hindered conservation and management efforts, especially where populations are declining or imperiled. We use nuclear and mitochondrial genetic data to clarify the identification and distribution of leopard frog species in this region. We focus on four problematic frog populations of uncertain species affiliation in northern NJ, southeastern mainland NY, and Staten Island to test the following hypotheses: (1) they are conspecific with Rana sphenocephala or R. pipiens, (2) they are hybrids between R. sphenocephala and R. pipiens, or (3) they represent one or more previously undescribed cryptic taxa. Bayesian phylogenetic and cluster analyses revealed that the four unknown populations collectively form a novel genetic lineage, which represents a previously undescribed cryptic leopard frog species, Rana sp. nov. Statistical support for R. sp. nov. was strong in both the Bayesian (pp=1.0) and maximum-likelihood (bootstrap=99) phylogenetic analyses as well as the Structure cluster analyses. While our data support recognition of R. sp. nov. as a novel species, we recommend further study including fine-scaled sampling and ecological, behavioral, call, and morphological analyses before it is formally described.

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

    USGS Publications Warehouse

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

    2003-01-01

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

  7. A new species of Rhabdias from lungs of the wood frog, Rana sylvatica, in North America: the last sibling of Rhabdias ranae?

    PubMed

    Tkach, Vasyl V; Kuzmin, Yuriy; Pulis, Eric E

    2006-06-01

    Rhabdias bakeri n. sp. is described from specimens found in lungs of the wood frog, Rana sylvatica, from North Dakota. The new species has previously been mistakenly identified as Rhabdias ranae Walton, 1929, a common parasite of the leopard frog, Rana pipiens. The new species differs from R. ranae and Rhabdias joaquinensis Ingles, 1935 by the shape and size of pseudolabia, shape and size of buccal capsule, and wider esophageal bulb. Molecular analysis based on the partial sequences of nuclear 18S rDNA gene, complete sequences of internal transcribed spacer region, and partial sequences of 28S gene demonstrates clear differences between Rhabdias from Ra. sylvatica and Ra. pipiens, and supports the status of R. bakeri as a new species.

  8. Pesticide distributions and population declines of California alpine frogs, Rana muscosa and Rana sierrae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 the Sierra Nevada moun...

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

    EPA Science Inventory

    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...

  10. Phylogeography of declining relict and lowland leopard frogs in the desert Southwest of North America

    USGS Publications Warehouse

    Olah-Hemmings, V.; Jaeger, J.R.; Sredl, M.J.; Schlaepfer, Martin A.; Jennings, R.D.; Drost, C.A.; Bradford, D.F.; Riddle, B.R.

    2010-01-01

    We investigated the phylogeography of the closely related relict leopard frog Rana onca (=Lithobates onca) and lowland leopard frog Rana yavapaiensis (=Lithobates yavapaiensis) – two declining anurans from the warm-desert regions of south-western North America. We used sequence data from mitochondrial DNA (mtDNA) to assess 276 individuals representing 30 sites from across current distributions. Our analysis supports a previously determined phylogenetic break between these taxa, and we found no admixing of R. onca and R. yavapaiensis haplotypes within our extensive sampling of sites. Our phylogeographic assessment, however, further divided R. yavapaiensis into two distinct mtDNA lineages, one representing populations across Arizona and northern Mexico and the other a newly discovered population within the western Grand Canyon, Arizona. Estimates of sequence evolution indicate a possible Early Pleistocene divergence of R. onca and R. yavapaiensis, followed by a Middle Pleistocene separation of the western Grand Canyon population of R. yavapaiensis from the main R. yavapaiensis clade. Phylogeographic and demographic analyses indicate population or range expansion for R. yavapaiensis within its core distribution that appears to predate the latest glacial maximum. Species distribution models under current and latest glacial climatic conditions suggest that R. onca and R. yavapaiensis may not have greatly shifted ranges.

  11. 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.

    PubMed

    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.

  12. The disappearing northern leopard frog (Lithobates pipiens): conservation genetics and implications for remnant populations in western Nevada

    PubMed Central

    Rogers, Serena D; Peacock, Mary M

    2012-01-01

    Global amphibian declines suggest a major shift in the amount and quality of habitat for these sensitive taxa. Many species that were once widespread are now experiencing declines either in part of or across their historic range. The northern leopard frog (Rana [Lithobates] pipiens] has undergone significant declines particularly in the western United States and Canada. Leopard frog population losses in Nevada are largely due to habitat fragmentation and the introduction of nonnative fish, amphibian, and plant species. Only two populations remain in the Truckee and Carson River watersheds of western Nevada which represents the western boundary of this species range. We used sequence data for an 812 base pair fragment of the mitochondrial NADH dehydrogenase 1 (ND1) gene to support a native origin for western Nevada populations. All frogs had a single haplotype (W07) from the distinct western North America ND1 haplotype clade. Data from seven polymorphic microsatellite loci show that Truckee and Carson River populations are highly differentiated from each other and from leopard frogs collected from eastern Nevada sites. Lack of gene flow among and distinct color morphs among the western Nevada populations likely predates the current geographical isolation. Comparisons with other peripheral L. pipiens populations show western Nevada populations have similar levels of gene diversity despite their contemporary isolation (HE 0.411, 0.482). Restoration of leopard frog populations in these watersheds will be challenging given well-entrenched nonnative bullfrog populations and major changes to the riparian zone over the past century. Declines of once common amphibian species has become a major conservation concern. Contemporary isolation of populations on a species range periphery such as the leopard frog populations in the Truckee and Carson rivers further exacerbate extirpation risk as these populations are likely to have fewer genetic resources to adaptively respond to

  13. Field evidence for linking Altosid applications with increased amphibian deformities in southern leopard frogs [abstract

    USGS Publications Warehouse

    Sparling, D.W.

    1998-01-01

    During the summer of 1997 we repeatedly sprayed Altosid, a formulation of 4% methoprene used for mosquito control, on six constructed macrocosms. Six additional macrocosms were sprayed with Abate4E, containing the organophosphate pesticide temephos, and six were sprayed with water (controls). The wetlands were created on an impermeable foundation for research purposes and averaged 215 m2 in area and 0.5 m deep. Application rates and frequency of Abate4E and Altosid followed label directions and mimicked procedures for mosquito control in National Wildlife Refuges. In early September juvenile frogs and metamorphing tadpoles were collected with dip nets from each pond and examined for deformities. In all, 91 juveniles and metamorph southern leopard frogs (Rana utricularia) were collected from Altosid sprayed wetlands with 14 (15%) demonstrating deformities. Seventyseven juveniles and metamorphs were collected from control wetlands with three (4%) showing deformities. Only six juveniles and metamorphs were collected from Abate4E wetlands and none showed deformities. Deformities included missing or deformed hind limbs (9 of 10 involving only the right hind limb), missing eyes, and abnormal color. The differences in rate of deformities was dependent on treatment (X2=6.44, p< 0.02). The number of leopard frogs caught per unit effort (tadpoles and juveniles) differed among treatments (p=0.032) with Abate4E wetlands producing fewer individuals per capture effort than either Altosid or control wetlands.

  14. Population status and population genetics of northern leopard frogs in Arizona

    USGS Publications Warehouse

    Theimer, Tad C.; Drost, Charles A.; O'Donnell, Ryan P.; Mock, Karen E.

    2011-01-01

    Increasing isolation of populations by habitat fragmentation threatens the persistence of many species, both from stochastic loss of small isolated populations, and from inbreeding effects in populations that have become genetically isolated. In the southwestern United States, amphibian habitat is naturally patchy in occurrence because of the prevailing aridity of the region. Streams, rivers, and other wetlands are important both as habitat and as corridors that connect populations. However, populations of some species have become more fragmented and isolated by habitat degradation and loss. Northern leopard frogs (Rana pipiens) have experienced serious declines in the Southwest. We conducted an extensive survey across the known range of northern leopard frogs in Arizona to determine the current distribution and abundance of the species. From a range that once spanned much of the northern and central part of the State, northern leopard frogs have been reduced to three or four widely separated populations, near Lyman Lake in east-central Arizona, in the Stoneman Lake area south of Flagstaff, along Truxton Wash near Peach Springs, and a population of uncertain extent on Navajo Nation lands. The Lyman Lake and Truxton Wash populations are small and extremely isolated. The Stoneman Lake population, however, is an extensive metapopulation spread across several stream drainages, including numerous ponds, wetlands, and artificial tanks. This is the only population in Arizona that is increasing in extent and numbers, but there is concern about the apparent introduction of nonnative genetic stock from eastern North America into this area. We analyzed genetic diversity within and genetic divergence among populations of northern leopard frogs, across both extant and recently extirpated populations in Arizona. We also analyzed mitochondrial DNA to place these populations into a larger phylogenetic framework and to determine whether any populations contained genetic material

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

    NASA Astrophysics Data System (ADS)

    Loman, Jon; Lardner, Björn

    2009-11-01

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

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

    USGS Publications Warehouse

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

    2005-01-01

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

  17. Metal levels in southern leopard frogs from the Savannah River Site: location and body compartment effects.

    PubMed

    Burger, J; Snodgrass, J

    2001-06-01

    Tadpoles have been proposed as useful bioindicators of environmental contamination; yet, recently it has been shown that metal levels vary in different body compartments of tadpoles. Metals levels are higher in the digestive tract of bullfrog (Rana catesbeiana) tadpoles, which is usually not removed during such analysis. In this paper we examine the heavy metal levels in southern leopard frog (R. utricularia) tadpoles from several wetlands at the Savannah River Site and test the null hypotheses that (1) there are no differences in metal levels in different body compartments of the tadpoles, including the digestive tract; (2) there are no differences in heavy metal levels among different wetlands; and (3) there are no differences in the ratio of metals in the tail/body and in the digestive tract/body as a function of metal or developmental stage as indicated by body weight. Variations in heavy metal levels were explained by wetland and body compartment for all metals and by tadpole weight for selenium and manganese. In all cases, levels of metals were higher in the digestive tract than in the body or tail of tadpoles. Metal levels were highest in a wetland that had been remediated and lowest in a wetland that was never a pasture or remediated (i.e., was truly undisturbed). Although tadpoles are sometimes eaten by fish and other aquatic predators, leopard frogs usually avoid laying their eggs in ponds with such predators. However, avian predators will eat them. These data suggest that tadpoles can be used as bioindicators of differences in metal levels among wetlands and as indicators of potential exposure for higher-trophic-level organisms, but that to assess effects on the tadpoles themselves, digestive tracts should be removed before analysis.

  18. Helminths of two native frog species (Rana chiricahuensis, Rana yavapaiensis) and one introduced frog species (Rana catesbeiana) (Ranidae) from Arizona.

    PubMed

    Goldberg, S R; Bursey, C R; Cheam, H

    1998-02-01

    The gastrointestinal tracts, lungs, urinary bladders, and body cavities of Rana catesbeiana (n = 25), Rana chiricahuensis (n = 25), and Rana yavapaiensis (N = 37) from Arizona were examined for helminths. Helminths representing 9 species of trematodes: Cephalogonimus brevicirrus, Glypthelmins quieta, Gorgoderina attenuata, Haematoloechus complexus, Haematoloechus langiplexus, Megalodiscus temperatus, Alaria sp., Clinostomum sp., and an unidentified strigeid; and 4 species of nematodes: Falcaustra catesbeianae, Rhabdias ranae, Physaloptera sp., and an unidentified ascarid were found. The helminth fauna of introduced R. catesbeiana differed markedly from that of native ranids. Helminths of R. chiricahuensis and R. yavapaiensis represent new host records. Arizona is a new locality record for C. brevicirrus, G. attenuata, H. complexus, H. longiplexus, M. temperatus, and R. ranae.

  19. Topological analysis of the brain stem of the frogs Rana esculenta and Rana catesbeiana.

    PubMed

    Opdam, R; Kemali, M; Nieuwenhuys, R

    1976-02-01

    The ventricular sulcal pattern and the cytoarchitectonic organization of the brain stem of the frogs Rana esculenta and Rana catesbeiana have been studied in transversely cut, Nissl stained serial sections. Four longitudinal sulci, the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans and the sulcus medianus superior could be distinguished in both species. A fifth longitudinal groove, the sulcus intermedius dorsalis, was found only in Rana esculenta. With the aid of the usual cytoarchitectonic criteria 25 cell masses have been delineated in Rana esculenta and 27 in Rana catesbeiana. These cell masses can be distributed over the following categories (numbers added in brackets for Rana catesbeiana, if different from those in Rana esculenta): primary efferent or motor, 8; primary afferent or sensory, 4(6); "relay" centers, 7. Contrary to statements in the literature the reticular formation can be divided into six separate cell groups. The majority of the nuclei form part of the central gray, which constitutes a rather wide zone in anurans; three reticular nuclei lie partly within the stratum griseum and partly within the stratum album; six nuclei are entirely embedded in the stratum album. The morphological pattern of the cell masses and their relationship to the ventricular sulci were studied with the aid of a graphical reconstruction procedure termed topological analysis (cf. Nieuwenhuys, '74 and figs. 15, 16). This analysis yielded the following results: The sulcus limitans extends throughout the rhombencephalon, dividing this brain part into a basal plate and an alar plate. The cell masses in the basal plate fit into two longitudinal zones, a medial area ventralis and a lateral area intermedioventralis. The area ventralis contains three somatic motor nuclei (IV, VI and XII) and the rhombencephalic medial reticular zone. The latter may be primarily considered as a somatic motor coordinating center. The area intermedioventralis contains

  20. ASYMMETRICAL EFFECTS OF INTRODUCED BULLFROGS (RANA CATESBEIANA) ON NATIVE RANID FROGS IN OREGON

    EPA Science Inventory

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are throught to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora...

  1. Interdigitating cells in the thymus of the frog, Rana temporaria.

    PubMed

    Bigaj, J; Płytycz, B

    1987-01-01

    Interdigitating cells (IDC) of the thymic medulla of the frog, Rana temporaria, collected in the summer, were examined by electron microscopy. The most characteristic cytological features of IDC are voluminous electron-lucent cytoplasm and widespread interdigitations and invaginations of the cell membrane. IDC possess an excentrically located nucleus with pronounced nucleoli and a thin rim of a dense chromatine as well as a perinuclear area with characteristic tubulo-vesicular complex. In our material Birbeck granules were absent. Some IDC contain phagocytized material. A few transitional forms between monocytes and IDC were observed. On the basis of these observations it is highly probable that the amphibian IDC belong to the mononuclear phagocyte system.

  2. Primary structures of skin antimicrobial peptides indicate a close, but not conspecific, phylogenetic relationship between the leopard frogs Lithobates onca and Lithobates yavapaiensis (Ranidae).

    PubMed

    Conlon, J Michael; Coquet, Laurent; Leprince, Jérôme; Jouenne, Thierry; Vaudry, Hubert; King, Jay D

    2010-04-01

    The phylogenetic relationship between the relict leopard frog Lithobates (Rana) onca (Cope, 1875) and the lowland leopard frog Lithobates (Rana) yavapaiensis (Platz and Frost, 1984) is unclear. Chromatographic analysis of norepinephrine-stimulated skin secretions from L. onca led to the identification of six peptides with antimicrobial activity. Determination of their primary structures indicated that four of the peptides were identical to brevinin-1Ya, brevinin-1Yb, brevinin-1Yc and ranatuerin-2Ya previously isolated from skin secretions of L. yavapaiensis. However, a peptide belonging to the temporin family (temporin-ONa: FLPTFGKILSGLF.NH(2)) and an atypical member of the ranatuerin-2 family containing a C-terminal cyclic heptapeptide domain (ranatuerin-2ONa: GLMDTVKNAAKNLAGQMLDKLKCKITGSC) were isolated from the L. onca secretions but were not present in the L. yavapaiensis secretions. Ranatuerin-2ONa inhibited the growth of Escherichia coli (MIC=50muM) and Candida albicans (MIC=100muM ) and showed hemolytic activity (LC(50)=90muM) but was inactive against Staphylococcus aureus. The data indicate a close phylogenetic relationship between L. onca and L. yavapaiensis but suggest that they are not conspecific species.

  3. Fat body of the frog Rana esculenta: an ultrastructural study.

    PubMed

    Zancanaro, C; Merigo, F; Digito, M; Pelosi, G

    1996-03-01

    In the frog, the fat body is the largest body lipid deposit and is associated with the gonad. The aim of the present work was to investigate the fine structure of the fat body at different periods of the annual cycle and during prolonged starvation. Results indicate that fat body cells of Rana esculenta caught in autumn and after winter hibernation resemble mammalian adipocytes of white adipose tissue and contain markers of adipose tissue, such as S-100 protein and lipoproteinlipase. However, unlike mammalian adipocytes, fat body adipocytes consistently show small lipid droplets associated with their single, large lipid deposits, a lack of a definite external lamina, and the presence of cellular prolongations and spicula at their surfaces. Transmission and scanning electron microscopy in association with lanthanum tracer experiments suggest that in fat body adipocytes a vesicular-tubular system connects the cytoplasm and the interstitial space. In June (i.e., during the reproductive period), fat body adipocytes appear to have lost much of their lipid deposit and adjacent adipocytes show interdigitation of their plasma membranes and prominent Golgi complexes. In starved frogs, fat body cells can be almost devoid of lipid and in regression to a near-mesenchymal state. Nevertheless, these fat bodies still contain lipoproteinlipase activity (approximately 45% of that found in lipid-filled ones), indicating persistent adipose differentiation of the cells therein. Results presented here show that the R. esculenta fat body is an adipose organ undergoing reversible extreme changes in adipocyte fat content, which are associated with definite ultrastructural features. The fat body represents a suitable model for studying adipose tissue under different and extreme physiological conditions.

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

    USGS Publications Warehouse

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

    2002-01-01

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

  5. Seasonal cycles in testicular activity in the frog, Rana perezi.

    PubMed

    Delgado, M J; Gutiérrez, P; Alonso-Bedate, M

    1989-01-01

    Studies of seasonal testicular cycle based on spermatogenetic activity and direct measurement of plasma testosterone were made in male frog Rana perezi obtained from its natural biotope in the Iberian Peninsula. Testosterone plasma level was determined by radioimmunoassay and exhibited notable differences according to season: plasma testosterone was lowest (less than 0.5 ng/ml) in summer and then increased progressively to reach a peak in spring (3-4 ng/ml), coincident with mating. After spermiation, when an increase in temperature and photoperiod in the natural habitat occurs, levels decline. Fat bodies also show a pronounced seasonal cycle with total regression following breeding and maximal development in winter. However, testicular weight was independent of seasons, and no significant change was observed throughout the year. Histological evidence indicates that although cell nests of different types are present every month of the year, the most important spermatogenetic activity is initiated in summer. The possible relationship between spermatogenetic activity and testosterone production and the importance of environmental factors as synchronizers of seasonal reproduction are discussed.

  6. Pathogenesis of Frog Virus 3 ( Ranavirus, Iridoviridae) Infection in Wood Frogs ( Rana sylvatica).

    PubMed

    Forzán, M J; Jones, K M; Ariel, E; Whittington, R J; Wood, J; Markham, R J Frederick; Daoust, P-Y

    2017-01-01

    Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 10(4.43) pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.

  7. Reproductive and lipid cycles in the male frog Rana ridibunda in northern Greece.

    PubMed

    Loumbourdis, N S; Kyriakopoulou-Sklavounou, P

    1991-01-01

    1. Reproductive and lipid cycles in the male frog Rana ridibunda were studied. 2. The spermatogenesis of Rana ridibunda is of the potentially continuous type. 3. During prehibernating season (September-November) a part of lipid is mobilized from fat bodies to other body sites or is transformed to other metabolites. 4. During wintering this frog consumes mainly glycogen. 5. In February the lipid is accumulated in the fat bodies and the liver mass shows a second peak, probably as a result of glycogen accumulation. 6. The greatest decrease of metabolites was observed during the breeding season and this is the result of the intensive activities related to the reproduction and maintenance.

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

    PubMed

    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.

  9. Reproductive strategies of leopard toad and mascarene frog from Giza, Egypt.

    PubMed

    Akef, Mamdouh S A

    2014-01-01

    I examined the reproductive strategies of leopard toad and mascarene frog by studying their annual vitellogenic cycle, monthly changes of masses of ovary, liver and fat bodies as well as egg size and number in two study areas, Abo Roash and El Mansuriya, and in the years 2001, 2005, and 2008-2009, particularly during the final two years of that period. Based on the presence of the mature ova, I found that vitellogenic cycle is continuous in toad, but discontinuous in frog. Further, leopard body reserves allocated more energy to vitellogenesis than did mascarene frog. Hence, fecundity in toad was higher than that in frog, as associated with higher egg number and size. During oviposition, female mascarene retained a small portion of a clutch, whereas toad shed all egg mass at once. Over the study period, both body and reproductive conditions reacted positively in toad, but negatively in frog. Warm temperature and long photoperiod elucidated ovarian development under high relative humidity in frog. In contrast, in toad, low relative humidity may be an environmental cue for the increase in ovarian mass. Thus, higher sexual activities occurred in spring for toad (dry environment), but in moist summer for frog. Ovarian mass and egg number were temperature-dependent in frog, but independent in toad. Relative humidity correlated significantly and negatively to egg size in both populations. It also related inversely to egg number in toad, but not in frog. Hence, eggs of the frog are controlled by both temperature and humidity in summer season. Rainfall had no effect on sexual parameters in both species.

  10. Do Frogs Still Get Their Kicks On Route 66? A Transcontinental Transect For Amphibian Chytrid Fungus (Batrachochytrium Dendrobatidis) Infection On U.S. Department Of Defense Installations

    DTIC Science & Technology

    2011-01-04

    samples during the spring/early summer sampling period (due to cold and snow ), when the majority of positive samples at other bases were collected (see... Leopard Frog (Rana pipiens) populations suggest intraspecies differences in resistance to pathogens. Develop Comp Immunol33: 1247-1257. Vredenburg VT...Woodhams DC, Hyatt AD, Boyle DG, Rollins-Smith LA (2007a) The Northern Leopard Frog Rana pipiens is a widespread reservoir species harboring

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

    USGS Publications Warehouse

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

    2009-01-01

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

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

    USGS Publications Warehouse

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

    2014-01-01

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

  13. Asymmetrical effects of introduced Rana catesbeiana on native ranid frogs in Oregon, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; Bury, R. Bruce; McCreary, B.

    2004-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

  14. Asymmetrical Effects of Introduced Bullfrogs (Rana catesbeiana) on Native Ranid Frogs in Oregon

    USGS Publications Warehouse

    Pearl, C.A.; Adams, M.J.; Bury, R.B.; McCreary, B.

    2004-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

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

    USGS Publications Warehouse

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

    2013-01-01

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

  16. IMPLICATIONS OF THE DISCOVERY OF RANA YAVAPAIENSIS IN THE WESTERN GRAND CANYON TO THE CONSERVATION STRATEGY FOR RANA ONCA

    EPA Science Inventory

    The minimum historical range of the relict leopard frog, Rana onca, comprises the drainages of the Virgin and Colorado rivers from the vicinity ofHurricane, Utah, to Black Canyon below Lake Mead, in Nevada and Arizona. Extant populations are known near only the Black Canyon and O...

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

  19. Survival estimates for reintroduced populations of the Chiricahua Leopard Frog (Lithobates chiricahuensis)

    USGS Publications Warehouse

    Howell, Paige E; Hossack, Blake R.; Muths, Erin L.; Sigafus, Brent H.; Chandler, Richard B.

    2016-01-01

    Global amphibian declines have been attributed to a number of factors including disease, invasive species, habitat degradation, and climate change. Reintroduction is one management action that is commonly used with the goal of recovering imperiled species. The success of reintroductions varies widely, and evaluating their efficacy requires estimates of population viability metrics, such as underlying vital rates and trends in abundance. Although rarely quantified, assessing vital rates for recovering populations provides a more mechanistic understanding of population growth than numerical trends in population occupancy or abundance. We used three years of capture-mark-recapture data from three breeding ponds and a Cormack-Jolly-Seber model to estimate annual apparent survival for reintroduced populations of the federally threatened Chiricahua Leopard Frog (Lithobates chiricahuensis) at the Buenos Aires National Wildlife Refuge (BANWR), in the Altar Valley, Arizona, USA. To place our results in context, we also compiled published survival estimates for other ranids. Average apparent survival of Chiricahua Leopard Frogs at BANWR was 0.27 (95% CI [0.07, 0.74]) and average individual capture probability was 0.02 (95% CI [0, 0.05]). Our apparent survival estimate for Chiricahua Leopard Frogs is lower than for most other ranids and is not consistent with recent research that showed metapopulation viability in the Altar Valley is high. We suggest that low apparent survival may be indicative of high emigration rates. We recommend that future research should estimate emigration rates so that actual, rather than apparent, survival can be quantified to improve population viability assessments of threatened species following reintroduction efforts.

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

    USGS Publications Warehouse

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

    2007-01-01

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

  1. Effects of exposure to cold on metabolic characteristics in gastrocnemius muscle of frog (Rana pipiens).

    PubMed Central

    Ohira, M; Ohira, Y

    1988-01-01

    1. Responses of enzymic characteristics of gastrocnemius muscle were studied when frogs (Rana pipiens) were exposed to cold environment (4 degrees C). 2. The content of adenosine triphosphate (ATP) decreased significantly after cold exposure. This decrease was greater in starved than in fed frogs. 3. Although the glycogen content did not change, lactate levels were lower in cold-exposed than room-temperature (control) frogs. No change was observed in glycogen and lactate between fed and unfed frogs kept at 4 degrees C for 2 months. Lactate dehydrogenase activity tended to increase during chronic cold exposure, but not significantly. 4. The activities of citrate synthase, cytochrome oxidase, and beta-hydroxyacyl CoA dehydrogenase were higher in gastrocnemius of chronically cold-exposed frogs than in room-temperature controls. This increase was statistically significant only in the muscles of starved frogs; these muscles had the greatest decrease in ATP. 5. It was suggested that chronic cold exposure decreases skeletal muscle ATP content but may not affect glycolysis. The data also suggested that the decrease in ATP content stimulates mitochondrial biogenesis which increases enzyme activities. PMID:3261790

  2. Endohelminth fauna of the marsh frog Rana ridibunda from Lake Hazar, Turkey.

    PubMed

    Saglam, Naim; Arikan, Hatice

    2006-10-27

    In this study, 236 marsh frogs Rana ridibunda collected from Lake Hazar (Elazig, Turkey) at 15 d intervals between March 2001 and February 2002 were examined for endohelminths; of these, 148 (62.71%) frogs were found to be infected with helminths. In total, 9 helminth species (3 trematodes, 5 nematodes and 1 acanthocephalan) were identified. We observed Gorgoderina vitelliloba (prevalence 2.97%) in the urinary bladder, Haematoloechus variegatus (4.66%) and Rhabdias bufonis (8.90%) in the lung, Pleurogenoides medians (1.69%), Oswaldocruzia filiformis (3.81 %) and Acanthocephalus ranae (26.27 %) in the small intestine, Neoxysomatium brevicaudatum (16.95%) and Cosmocercoides sp. (3.39%) in the large intestine, and Eustrongylides excisus (14.41%) in the body cavity and on,the stomach. No helminth was found in the spleen, kidney, gall bladder, liver, heart or muscle. Of the 9 helminth species identified, Acanthocephalus ranae (26.27 %) had the highest prevalence and abundance and Oswaldocruzia filiformis (8.33+/-4.09) had the highest mean intensity.

  3. Diet of introduced bullfrogs (Rana catesbeiana): Predation on and diet overlap with native frogs on Daishan Island, China

    USGS Publications Warehouse

    Wu, Zhengjun; Li, Y.; Wang, Y.; Adams, Michael J.

    2005-01-01

    We examined diet of introduced Bullfrogs (Rana catesbeiana) and three native frog species (Rana limnocharis, Rana nigromaculata, and Bufo bufo gargarizans) co-occurring at a group of ponds on Daishan Island, east of China, to gain insight into the nature of potential interactions between Bullfrogs and native frog species. For postmetamorphic Bullfrogs, aquatic prey items dominated volumetrically. Prey size, diet volume and volumetric percentage of native frogs in diet increased with Bullfrog body size. The number and volumetric percentage of native frogs in the diet were not different for female and male Bullfrogs, and both were higher for adults than for juveniles. Diet overlap between males and juveniles was higher than that between males and females and between females and juveniles. Diet overlap with each native frog species of male Bullfrogs was lower than that of female Bullfrogs and juvenile Bullfrogs. We did not exam effects of Bullfrogs on native frogs but our results suggest that the primary threat posed by juvenile Bullfrogs to native frogs on Daishan Island is competition for food, whereas the primary threat posed by male Bullfrogs is direct predation. Female Bullfrogs may threaten native frogs by both competition and predation. These differences among Bullfrog groups may be attributed to differences in body size and microhabitat use.

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

    USGS Publications Warehouse

    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

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

    PubMed

    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.

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

    USGS Publications Warehouse

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

    2013-01-01

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

  7. Lead concentrations in bullfrog Rana catesbeiana and green frog R. clamitans tadpoles inhabiting highway drainages

    USGS Publications Warehouse

    Birdsall, C.W.; Grue, C.E.; Anderson, A.

    1986-01-01

    Lead concentrations were determined in sediment and tadpoles of bullfrogs Rana catesbeiana and green frogs R. clamitans from drainages along highways with different daily average traffic volumes (range, 4272 to I08,800 vehicles day-I) and from ponds >0.4 km from the nearest highway. Lead concentrations (mg kg--I dry weight) in sediment (7-8 to 940) were usually greater (4-5 times) than those in the tadpoles (bullfrog, 0,07 to 270; green frog, 0,90 to 240 mg kg-I). Lead concentrations in sediment (r =0.63) and in both species of tadpoles (bullfrog, r = 0.69; green frog, r = 0.57) were positively correlated with average daily traffic volume. Lead concentrations in both species of tadpoles (bullfrog, r = (). 76: green frog, r = 0.75) were also positively correlated with lead concentrations in sediment. At sites where both bullfrog and green frog tadpoles were collected. lead concentrations in the two species were closely related (r = 0.84). Lead concentrations in tadpoles living near highways may contribute to the elevated lead levels reported in wildlife that are potential tadpole predators. Dietary lead concentrations similar to those in our tadpoles have been associated with physiological and reproductive effects in some species of birds and mammals. However, additional data are needed to determine the hazards to predators of lead concentrations in tadpoles.

  8. [Role of the hypothalamus in the regulation of primary sleep in the frog Rana temporaria].

    PubMed

    Shilling, N V

    1980-01-01

    It has been demonstrated that in the frog Rana temporaria the anterior hypothalamus is involved into regulation of the depth of two forms of rest--one with plastic, the other with decreased muscle tone. Resting state with catatonic muscle activity is associated with activation of the posterior hypothalamus. Participation of the anterior hypothalamus in regulation of the resting state with the decreased tone of skeletal muscles may be taken as one of the indications that this form of rest plays the role of sleep in amphibians, being transformed during evolution of vertebrates into the sleep of poikilotherms.

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

    PubMed

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

    2011-04-15

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

  10. [Role of acetylcholine in the Ca2+-dependent regulation of functional activity of myocardium of frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2008-01-01

    To study role of ACh in the Ca2+-dependent regulation of rhythm and strength of cardiac contractions in frog Rana temporaria, the ACh chrono- and inotropic effects have been studied in parallel experiments on the background of blockers of potential-controlled Ca2+-channels, ryanodine and muscarine receptors. The obtained results indicate participation of acetylcholine in the Ca2+-dependent regulation of rhythm and strength of frog cardiac contractions.

  11. Status of RNAs, localized in Xenopus laevis oocytes, in the frogs Rana pipiens and Eleutherodactylus coqui.

    PubMed

    Nath, Kimberly; Boorech, Jamie L; Beckham, Yvonne M; Burns, Mary M; Elinson, Richard P

    2005-01-15

    Early development in the frog model, Xenopus laevis, is governed by RNAs, localized to the vegetal cortex of the oocyte. These RNAs include Xdazl RNA, which is involved in primordial germ cell formation, and VegT RNA, which specifies the mesoderm and endoderm. In order to determine whether orthologues of these RNAs are localized and have similar functions in other frogs, we cloned RpDazl and RpVegT from Rana pipiens, a frog that is phylogenetically distant from X. laevis. RNAs from both genes are localized to the vegetal cortex of the R. pipiens oocyte, indicating that the vegetal localization is likely the basal state. The animal location of EcVegT RNA in Eleutherodactylus coqui that we found previously (Beckham et al., 2003) is then a derived state, probably due to the great increase in egg size required for direct development of this species. To answer the question of function, we injected RpVegT or EcVegT RNAs into X. laevis embryos, and assayed animal caps for gene expression. Both of these RNAs induced the expression of endodermal, mesodermal, and organizer genes, showing that the function of RpVegT and EcVegT as meso-endodermal determinants is conserved in frogs. The RNA localizations and the function of VegT orthologues in germ layer specification may be synapomorphies for anuran amphibians.

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

    PubMed

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

    2008-09-01

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

  13. Post-Wildfire Sedimentation in Saguaro National Park, Rincon Mountain District, and Effects on Lowland Leopard Frog Habitat

    USGS Publications Warehouse

    Parker, John T.C.

    2006-01-01

    The Rincon Mountain District of Saguaro National Park occupies about 272 square kilometers of mountains, canyons, and alluvial fans in southeastern Arizona just east of Tucson. The park contains some of the last remaining habitat in the Tucson Basin of the lowland leopard frog that lives in the bedrock pools called tinajas in canyons at elevations between 850 and 1,800 meters. Those tinajas that contain water year-round are critical winter habitat for tadpoles, and the breeding success of the leopard frogs depends on these features. In recent years, many tinajas that previously had provided habitat for the leopard frogs have been buried beneath large volumes of coarse sandy gravel that resulted from severe, stand-replacing wildfires in the watersheds above them. The U. S. Geological Survey in cooperation with the National Park Service, conducted a study in 2004-06 to determine critical sediment-source areas, and the mechanisms of sediment delivery from hillslopes to stream channels to areas of leopard frog habitat and to estimate the increase in rates of sedimentation resulting from wildfires. Spatial data of watershed characteristics, as well as historical data, including photographs, monitoring surveys, precipitation and stream discharge records, were used in conjunction with field observations conducted between spring 2004 and fall 2005. The Helens II fire in 2003, the fifth largest wildfire to burn in the Rincon Mountains since 1989, offered an opportunity to observe mechanisms of sediment erosion, transport, and deposition in the immediate post-fire environment. Reduction of the forest canopy, understory vegetation, and organic litter on the ground surface in severe burn areas caused increased surface runoff in the Joaquin Canyon watershed that led to intensified erosion of hillslopes. An initial flush of fine material, mostly ash, was transported to lower channel reaches with the first significant precipitation event following the fire. Subsequently, the main

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

    PubMed

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

    2016-12-01

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

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

    PubMed Central

    Dieni, Christopher A; Storey, Kenneth B

    2008-01-01

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

  16. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota.

    PubMed

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V

    2013-08-01

    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

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

    PubMed

    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.

  18. Recent Emergence of a Chytrid Fungal Pathogen in California Cascades Frogs (Rana cascadae).

    PubMed

    De León, Marina E; Vredenburg, Vance T; Piovia-Scott, Jonah

    2016-12-12

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with global amphibian declines, but it is often difficult to discern the relative importance of Bd as a causal agent in declines that have already occurred. Retrospective analyses of museum specimens have allowed researchers to associate the timing of Bd arrival with the timing of past amphibian declines. Cascades frogs (Rana cascadae) have experienced dramatic declines in northern California, but it is not clear whether the onset of these declines corresponds to the arrival of Bd. We used quantitative real-time PCR assays of samples collected from museum specimens to determine historical Bd prevalence in the northern California range of Cascades frogs. We detected Bd in 13 of 364 (3.5%) Cascades frog specimens collected between 1907 and 2003, with the first positive result from 1978. A Bayesian analysis suggested that Bd arrived in the region between 1973 and 1978, which corresponds well with the first observations of declines in the 1980s.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

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

    PubMed

    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.

  2. Experimental exposure of adult San Marcos salamanders and larval leopard frogs to the cercariae of Centrocestus formosanus.

    PubMed

    Huston, D C; Cantu, V; Huffman, D G

    2014-04-01

    The gill parasite Centrocestus formosanus (Trematoda: Heterophyidae) is an exotic parasite of concern in Texas because it has been shown to infect multiple threatened and endangered fish species. The purpose of this study was to determine if C. formosanus could present a threat to larval anurans, as well as threatened neotenic salamanders endemic to the spring-fed systems of Texas. We exposed adults of the San Marcos salamander Eurycea nana (Caudata: Plethodontidae) and tadpoles of the Rio Grande leopard frog Lithobates berlandieri (Anura: Ranidae) to the cercariae of C. formosanus . The San Marcos salamander showed no signs of metacercarial infection, suggesting that E. nana may be refractory to C. formosanus cercariae. Centrocestus formosanus readily infects the gills of leopard frog tadpoles, but the metacercariae apparently died prior to reaching maturity in our tadpoles.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  4. Cryptic Diversity in Metropolis: Confirmation of a New Leopard Frog Species (Anura: Ranidae) from New York City and Surrounding Atlantic Coast Regions

    PubMed Central

    Feinberg, Jeremy A.; Newman, Catherine E.; Watkins-Colwell, Gregory J.; Schlesinger, Matthew D.; Zarate, Brian; Curry, Brian R.; Shaffer, H. Bradley; Burger, Joanna

    2014-01-01

    We describe a new cryptic species of leopard frog from the New York City metropolitan area and surrounding coastal regions. This species is morphologically similar to two largely parapatric eastern congeners, Rana sphenocephala and R. pipiens. We primarily use bioacoustic and molecular data to characterize the new species, but also examine other lines of evidence. This discovery is unexpected in one of the largest and most densely populated urban parts of the world. It also demonstrates that new vertebrate species can still be found periodically even in well-studied locales rarely associated with undocumented biodiversity. The new species typically occurs in expansive open-canopied wetlands interspersed with upland patches, but centuries of loss and impact to these habitats give some cause for conservation concern. Other concerns include regional extirpations, fragmented extant populations, and a restricted overall geographic distribution. We assign a type locality within New York City and report a narrow and largely coastal lowland distribution from central Connecticut to northern New Jersey (based on genetic data) and south to North Carolina (based on call data). PMID:25354068

  5. Cryptic diversity in metropolis: confirmation of a new leopard frog species (Anura: Ranidae) from New York City and surrounding Atlantic coast regions.

    PubMed

    Feinberg, Jeremy A; Newman, Catherine E; Watkins-Colwell, Gregory J; Schlesinger, Matthew D; Zarate, Brian; Curry, Brian R; Shaffer, H Bradley; Burger, Joanna

    2014-01-01

    We describe a new cryptic species of leopard frog from the New York City metropolitan area and surrounding coastal regions. This species is morphologically similar to two largely parapatric eastern congeners, Rana sphenocephala and R. pipiens. We primarily use bioacoustic and molecular data to characterize the new species, but also examine other lines of evidence. This discovery is unexpected in one of the largest and most densely populated urban parts of the world. It also demonstrates that new vertebrate species can still be found periodically even in well-studied locales rarely associated with undocumented biodiversity. The new species typically occurs in expansive open-canopied wetlands interspersed with upland patches, but centuries of loss and impact to these habitats give some cause for conservation concern. Other concerns include regional extirpations, fragmented extant populations, and a restricted overall geographic distribution. We assign a type locality within New York City and report a narrow and largely coastal lowland distribution from central Connecticut to northern New Jersey (based on genetic data) and south to North Carolina (based on call data).

  6. Epidermal Laser Stimulation of Action Potentials in the Frog Sciatic Nerve

    DTIC Science & Technology

    2008-10-01

    Laser Stimulation of Action Potentials in the Frog Sciatic Nerve Nichole M. Jindra Robert J. Thomas Human Effectiveness Directorate Directed...in the Frog Sciatic Nerve 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62202F 6. AUTHOR(S) .Nichole M. Jindra, Robert J. Thomas, Douglas N...Alan Rice 14. ABSTRACT Measurements of laser stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) were made using

  7. The isolated and perfused working heart of the frog, Rana esculenta: an improved preparation.

    PubMed

    Acierno, R; Gattuso, A; Cerra, M C; Pellegrino, D; Agnisola, C; Tota, B

    1994-05-01

    1. An in vitro preparation of the intact heart of the frog Rana esculenta was set up. 2. The isolated heart, perfused at constant pressure, was spontaneously beating and able to generate physiological values of output pressure, cardiac output, ventricle work and power. It showed the typical phenomenon of the "hypodynamic state" after a relatively constant time from the onset of the perfusion. 3. Perfusion with air-saturated saline and 99.5% oxygen-saturated saline did not show significant differences in the recorded parameters. 4. This experimental model represents a useful tool for physiological and pharmacological studies, especially when the direct analysis of the effects of hormones, mediators or drugs requires an intact heart preparation.

  8. UBPy/MSJ-1 system during male germ cell progression in the frog, Rana esculenta.

    PubMed

    Meccariello, Rosaria; Chianese, Rosanna; Scarpa, Donatella; Berruti, Giovanna; Cobellis, Gilda; Pierantoni, Riccardo; Fasano, Silvia

    2007-01-01

    mUBPy (mouse ubiquitin specific processing protease) is a de-ubiquitinating enzyme expressed in mouse testis and brain. In testis, it interacts with the DnaJ protein MSJ-1 (mouse sperm cell specific DnaJ first homologue), a molecular chaperone expressed in spermatids and spermatozoa. Since MSJ-1 is conserved among vertebrates, to demonstrate an evolutionarily conserved function of UBPy/MSJ-1 system, we assayed mUBPy presence in the anuran amphibian, the frog, Rana esculenta, during the annual sexual cycle. By Western blot we have detected a specific signal of 126kDa in testis and isolated spermatozoa. During the annual sexual cycle, the signal gradually increases as soon as spermatogenesis resumes after the winter stasis. Using immunocytochemistry, we have localized the protein in spermatids and spermatozoa. In conclusion, UBPy/MSJ-1 system is available in R. esculenta testis suggesting a conserved fundamental function in spermatogenesis and sperm formation.

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

    PubMed

    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.

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

    USGS Publications Warehouse

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

    2007-01-01

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

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

    USGS Publications Warehouse

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

    2001-01-01

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

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

    USGS Publications Warehouse

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

    2001-01-01

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

  13. Comparative microhabitat characteristics at oviposition sites of the California red-legged frog (Rana draytonii)

    USGS Publications Warehouse

    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.

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

    PubMed

    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.

  15. Size-sex variation in survival rates and abundance of pig frogs, Rana grylio, in northern Florida wetlands

    USGS Publications Warehouse

    Wood, K.V.; Nichols, J.D.; Percival, H.F.; Hines, J.E.

    1998-01-01

    During 1991-1993, we conducted capture-recapture studies on pig frogs, Rana grylio, in seven study locations in northcentral Florida. Resulting data were used to test hypotheses about variation in survival probability over different size-sex classes of pig frogs. We developed multistate capture-recapture models for the resulting data and used them to estimate survival rates and frog abundance. Tests provided strong evidence of survival differences among size-sex classes, with adult females showing the highest survival probabilities. Adult males and juvenile frogs had lower survival rates that were similar to each other. Adult females were more abundant than adult males in most locations at most sampling occasions. We recommended probabilistic capture-recapture models in general, and multistate models in particular, for robust estimation of demographic parameters in amphibian populations.

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

    USGS Publications Warehouse

    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.

  17. Physiological evidence for β3-adrenoceptor in frog (Rana esculenta) heart.

    PubMed

    Mazza, Rosa; Angelone, Tommaso; Pasqua, Teresa; Gattuso, Alfonsina

    2010-11-01

    β3-Adrenergic receptors (ARs) have been recently identified in mammalian hearts where, unlike β1- and β2-ARs, induce cardio-suppressive effects. The aim of this study was to describe β3-AR role in the frog (Rana esculenta) heart and to examine its signal transduction pathway. The presence of β3-AR, by using Western blotting analysis, has been also identified. BRL(37344), a selective β3-AR agonist, induced a dose-dependent negative inotropic effect at concentrations from 10(-12) to 10(-6)M. This effect was not modified by nadolol (β1/β2-AR antagonist) and by phentolamine (α-AR antagonist), but it was suppressed by the β3-AR-specific antagonist SR(59230) and by exposure to the Gi/o proteins inhibitor Pertussis Toxin. In addition, the involvement of EE-NOS-cGMP-PKG/PDE2 pathway in the negative inotropism of BRL(37344) has been assessed. BRL(37344) treatment induced eNOS and Akt phosphorylation as well as an increase of cGMP levels. β3-ARs activation induce a non-competitive antagonism against ISO stimulation which disappeared in presence of PKG and PDE2 inhibition. Taken together our findings provide, for the first time in the frog, a role for β3-ARs in the cardiac performance modulation which involves Gi/o protein and occurs via an EE-NO-cGMP-PKG/PDE2 cascade.

  18. Growth and development of larval green frogs (Rana clamitans) exposed to multiple doses of an insecticide

    USGS Publications Warehouse

    Boone, M.D.; Bridges, C.M.; Rothermel, B.B.

    2001-01-01

    Our objective was to determine how green frogs (Rana clamitans) are affected by multiple exposures to a sublethal level of the carbamate insecticide, carbaryl, in outdoor ponds. Tadpoles were added to 1,000-1 ponds at a low or high density which were exposed to carbaryl 0, 1, 2, or 3 times. Length of the larval period, mass, developmental stage, tadpole survival, and proportion metamorphosed were used to determine treatment effects. The frequency of dosing affected the proportion of green frogs that reached metamorphosis and the developmental stage of tadpoles. Generally, exposure to carbaryl increased rates of metamorphosis and development. The effect of the frequency of carbaryl exposure on development varied with the density treatment; the majority of metamorphs and the most developed tadpoles came from high-density ponds exposed to carbaryl 3 times. This interaction suggests that exposure to carbaryl later in the larval period stimulated metamorphosis, directly or indirectly, under high-density conditions. Our study indicates that exposure to a contaminant can lead to early initiation of metamorphosis and that natural biotic factors can mediate the effects of a contaminant in the environment.

  19. Effects of carbaryl on green frog (Rana clamitans) tadpoles: Timing of exposure versus multiple exposures

    USGS Publications Warehouse

    Boone, M.D.; Bridges, C.M.

    2003-01-01

    The majority of studies on pesticide impacts have evaluated the effects of single exposures. However, multiple exposures to a pesticide may be more prevalent. The objective of our study was to determine how multiple exposures versus single exposure at different times during development affected survival to metamorphosis, tadpole survival, tadpole mass, and tadpole developmental stage of green frog (Rana clamitans) tadpoles reared at low and high density in outdoor cattle tank ponds. Tadpoles were exposed to carbaryl zero, one, two, or three times at 14-d intervals. We applied single doses of carbaryl at one of three times, specifically during early, mid, or late development. Overall, we found that multiple exposures had a greater impact than single exposures during development. More individuals reached metamorphosis in ponds exposed to multiple doses of carbaryl compared with controls, indicating that the presence of carbaryl stimulated metamorphosis. The presence of carbaryl in the aquatic environment also resulted in more developed tadpoles compared with controls. Tadpoles in control ponds did not reach metamorphosis and were less developed than individuals exposed to carbaryl; this effect indicates that, under ideal conditions, green frogs could overwinter in ponds so that greater size could be attained before metamorphosis in the following spring or summer. Our study demonstrated the importance of including realistic application procedures when evaluating the effects of a pesticide and that multiple exposures to a short-lived pesticide are more likely to affect an amphibian population.

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

    PubMed

    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.

  1. [Resident and circulating mast cells in propulsative organs of the frog Rana temporaria].

    PubMed

    Krylova, M I

    2009-01-01

    Mast cells (MCs) of the "blood" and lymph hearts of the adult frog Rana temporaria were investigated at histochemical and ultrastructural levels. Two populations of MCs were revealed in these propulsative organs: population of resident MCs and population of circulating MCs. It has been shown that the resident cardiac MCs have an oval or elongated form and are located between atrial or ventricular myocytes and under endocardial endothelium. The resident cardiac MCs are situated in connective tissue of epicardium, too. Avascular myocardium of the frog ventricle consists of a spongy network of muscle trabeculae. We revealed circulating MCs in intertrabecular spaces and clefts of the spongy myocardium and in the blood of the main central cavity. Circulating MCs are round in shape and contain a large central nucleus enriched with condensed chromatin. They resemble the lymphocytes, but show cytoplasm filled with granules. These granules ultrastructure is much like that of the granules of the cardiac resident MCs. In the lymph heart, oval and somewhat elongated resident MCs are located in the interstitial space among cross-striated muscle fibers and among smooth muscle cells of tubular (afferent and efferent) valves. Sometimes lymphocyte-like circulating MCs are revealed in the cavity of lymph heart. Circulating MCs are also present in the lymphatics located adjacent to the lymph hearts. In certain parts of the lymphatic walls MCs are in close adhesion to the mesothelial cells lining the lymphatic cavity. Our histochemical investigation revealed that both the resident and circulating MCs of the propulsative organs give a strongly positive reaction with alcian blue, but weakly red with safranin and weakly metachromatic with toluidine blue. The presence of population of circulating MCs in the frog suggests that there are differences in biology of MCs between lower and higher vertebrates.

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

    USGS Publications Warehouse

    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

  3. Unlikely Remedy: Fungicide Clears Infection from Pathogenic Fungus in Larval Southern Leopard Frogs (Lithobates sphenocephalus)

    PubMed Central

    Hanlon, Shane M.; Kerby, Jacob L.; Parris, Matthew J.

    2012-01-01

    Amphibians are often exposed to a wide variety of perturbations. Two of these, pesticides and pathogens, are linked to declines in both amphibian health and population viability. Many studies have examined the separate effects of such perturbations; however, few have examined the effects of simultaneous exposure of both to amphibians. In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus) to the chytrid fungus Batrachochytrium dendrobatidis and the fungicide thiophanate-methyl (TM) at 0.6 mg/L under laboratory conditions. The experiment was continued until all larvae completed metamorphosis or died. Overall, TM facilitated increases in tadpole mass and length. Additionally, individuals exposed to both TM and Bd were heavier and larger, compared to all other treatments. TM also cleared Bd in infected larvae. We conclude that TM affects larval anurans to facilitate growth and development while clearing Bd infection. Our findings highlight the need for more research into multiple perturbations, specifically pesticides and disease, to further promote amphibian heath. PMID:22912890

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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

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

    USGS Publications Warehouse

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  9. Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature.

    PubMed

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2008-03-01

    It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy.

  10. Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA

    USGS Publications Warehouse

    Fellers, G.M.; McConnell, L.L.; Pratt, D.; Datta, S.

    2004-01-01

    In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46 ?? 20 ng/g wet wt at Tablelands and 17 ?? 8 Sixty Lakes). Both ??-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

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

    USGS Publications Warehouse

    Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

    2015-01-01

    In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

  12. [Morpho-functional changes in small intestine epithelium of frog Rana temporaria during hibernation].

    PubMed

    Seliverstova, E V; Prutskova, N P

    2012-01-01

    Structure and function of small intestinal epithelium were studied in overwintering frogs Rana temporaria at various stages of hibernation. In the process of testing of absorption of arginine vasotocin (AVT) in experiments in vitro it is established that at the period of hibernation there is preserved the capability of the epithelium for absorption of this nonapeptide without hydrolysis. However, as compared with October-December, in January-February and later, a decrease of the AVT absorption takes place, which is the most pronounced in March-April. Changes in epithelial structures appear by the middle of winter and are progressing by spring. In April-May, as compared with the beginning of hibernation, the height of enterocytes, the length of microvilli, and the number of microvilli decrease by 33 %, 40 %, and 57 %, respectively. The absence of features of destruction indicates an adaptive character of the observed changes. Dynamics of the studied parameters indicates morphological plasticity of the small intestine epithelium of R. temporaria at the period of hibernation.

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

    USGS Publications Warehouse

    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.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  17. Effect of temperature on electrical resonance in leopard frog saccular hair cells.

    PubMed

    Smotherman, M S; Narins, P M

    1998-01-01

    Leopard frog saccular hair cells exhibit an electrical resonance in response to a depolarizing stimulus that has been proposed to contribute to the tuning properties of the frog sacculus by acting as an electrical band-pass filter. With the whole cell patch-clamp technique, we have investigated the effect of temperature on electrical resonances in isolated saccular hair cells, and we have described the effects of temperature on the currents and channel kinetics underlying electrical resonance. A hair cell's onset resonant frequency in response to a constant depolarizing current pulse increases linearly with temperature at a rate of 11 Hz/1 degrees C, exhibiting a mean Q10 of 1.7 between 15 and 35 degrees C. However, offset resonant frequencies continue to double every 10 degrees C, exhibiting a mean Q10 of 2.1. If steady-state voltage during the stimulus is held constant, all oscillatory frequencies increase with a mean Q10 of 2.1. The average level of steady-state depolarization during a +150-pA depolarizing current pulse decreases with increasing temperature (-6 mV from 15 to 25 degrees C). This temperature-dependent reduction of the steady-state membrane potential causes a shift in the voltage-dependent channel kinetics to slower rates, thus reducing the apparent Q10 for onset resonant frequencies. The peak outward tail current and net steady-state outward current, which is the sum of a voltage-dependent inward calcium current (ICa) and an outward calcium-dependent potassium current (IK(Ca)), increase with temperature, exhibiting a mean Q10 of 1.7 between 15 and 25 degrees C. The activation rate (T1/2) of the outward current exhibits a mean Q10 of 2.3 between 15 and 25 degrees C, while the deactivation rate (taurel) exhibits a mean Q10 of 2.9 over the same temperature range. These results support previous models of the molecular determination of resonant frequency, which have proposed that a combination of IK(Ca) channel kinetics and the overall magnitude of the

  18. Falcaustra lowei n. sp. and other helminths from the Tarahumara frog, Rana tarahumarae (Anura: Ranidae), from Sonora, Mexico.

    PubMed

    Bursey, C R; Goldberg, S R

    2001-04-01

    Seventy-four specimens of Falcaustra lowei n. sp. were recovered from the intestines of 9 of 42 (21%) Tarahumara frogs. Rana tarahumarae, from Sonora, Mexico. F. lowei is the 14th Nearctic species to be described and belongs to that group of species possessing a pseudosucker, namely F. catesbeianae, F. chabaudi, F. chelydrae, F. mexicana, and F. wardi. The new species can be readily differentiated from these by the arrangement of caudal papillae and length of spicules. Priority description of F. affinis is established and F. concinnae is removed from synonymy with F. affinis. In addition to F. lowei, 3 species of Digenea, Glypthelmins quieta, Haematoloechus breviplexus, Langeronia macrocirra; 1 species of Eucestoda, Ophiotaenia magna; 7 species of Nematoda, F. inglisi, Foleyellides striatus, Oswaldocruzia pipiens, Rhabdias ranae, Subulascaris falcaustriformis, Physaloptera sp. (larvae): and 1 species of Acanthocephala, an unidentified oligacanthorhynchid cystacanth, were found.

  19. Response to pinealectomy and blinding in vitellogenic female frogs (Rana perezi) subjected to high temperature in autumn.

    PubMed

    Alonso-Gómez, A L; Tejera, M; Alonso-Bedate, M; Delgado, M J

    1990-01-01

    The present experiments were carried out to investigate the effects of pinealectomy and bilateral enucleation on the ovarian activity in Rana perezi frogs maintained in 12-h light--12-h dark photoperiod and 20 +/- 1 degrees C during the vitellogenetic growth in late autumn. These environmental conditions, mainly temperature, induce a gonadal and metabolic response similar to that observed in the natural habitat in summer: a marked ovarian follicular regression, a depletion of the energetic resources from fat bodies and liver, and a minimum in oestradiol circulating levels. This response is partially blocked by pinealectomy and blinding. Protein phosphorus, as an index of vitellogenic proteins, and total ovary lipid content were significantly higher in pinealectomized and blinded frogs with respect to sham-operated animals. Likewise, oestradiol concentrations showed a significant increase during the dark phase of the daily photocycle in pinealectomized and blinded animals. From our results, we can suggest that the arrest of vitellogenesis, the depletion of energetic resources, and the regulation of oestradiol levels induced by the high temperature in Rana perezi frogs can be influenced, at least in part, by the pineal complex and lateral eyes.

  20. Ontogenic delays in effects of nitrite exposure on tiger salamanders (Ambystoma tigrinum tigrinum) and wood frogs (Rana sylvatica).

    PubMed

    Griffis-Kyle, Kerry L

    2005-06-01

    Under certain conditions, nitrite can be present in freshwater systems in quantities that are toxic to the fauna. I exposed wood frog (Rana sylvatica) and eastern tiger salamander (Ambystoma tigrinum tigrinum) embryos and young tadpoles and larvae to elevated concentrations of nitrite in chronic toxicity tests: 0, 0.3, 0.6, 1.2, 2.1, 4.6, and 6.1 mg/L NO2-N, exposing individuals as both embryos and larvae. Nitrite caused significant declines in wood frog hatching success (3.4 mg/L NO2-N, wood frog), and lower concentrations caused significant mortality during the early larval stages (4.6 mg/L NO2-N, salamander; 0.5 mg/L NO2-N, wood frog). Later tests exposing individuals to nitrite only after hatching showed that both wood frog and tiger salamander vulnerability to nitrite declined shortly after hatching. Hence, examining a single life-history stage, especially later in development, may miss critical toxic effects on organisms, causing the researcher potentially to underestimate seriously the ecological consequences of nitrite exposure.

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

    USGS Publications Warehouse

    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.

  2. Odorous and Non-Fatal Skin Secretion of Adult Wrinkled Frog (Rana rugosa) Is Effective in Avoiding Predation by Snakes

    PubMed Central

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

    PubMed

    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.

  4. Female Choice for Males with Greater Fertilization Success in the Swedish Moor Frog, Rana arvalis

    PubMed Central

    Sherman, Craig D. H.; Sagvik, Jörgen; Olsson, Mats

    2010-01-01

    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. PMID:21049015

  5. Gonadal differentiation in frogs, Rana japonica and R. brevipoda, raised from UV irradiated eggs

    SciTech Connect

    Shirane, T.

    1982-10-10

    The gonadal differentiation of anurans, Rana japonica and R. brevipoda, was examined in animals raised from eggs which had been irradiated at the vegetal hemisphere with UV (9300 erg/mm2) at the 2-cell stage. In R. japonica about 70% of the larvae at stage I from the pressed and UV-irradiated eggs were germ cell free, but at a stage immediately after metamorphosis all animals had at least some germ cells, although their gonads often were extremely small and poorly differentiated. When male animals matured sexually, many of them had abnormal gonads. However, all of them were shown by artificial means to be capable of fertilization. In the nonpressed and irradiated group, no larvae were germ cell free and the animals immediately after metamorphosis showed nearly normal gonadal differentiation except for the presence of a few degenerate oocytes in the ovaries. The results in R. brevipoda were basically similar to those in R. japonica. In both species, sex ratios were determined at two stages, the first immediately after metamorphosis and the other when the animals matured, as based on gonad morphology and histology and on external sexually dimorphic characters as well. Sex ratios at these two stages in frogs from the pressed and irradiated eggs differed markedly in R. brevipoda. The ratio was normal at metamorphosis but high M/F ratios occurred when animals became mature. That sex reversal took place in this species as well as in R. japonica (in which sex-ratio deviation was not statistically significant) was supported by the sex ratios of the progenies of these supernumerary males.

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

    PubMed

    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.

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

    PubMed

    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.

  8. Gonadal differentiation in frogs, Rana japonica and R. brevipoda, raised from UV irradiated eggs.

    PubMed

    Shirane, T

    1982-10-10

    The gonadal differentiation of anurans, Rana japonica and R. brevipoda, was examined in animals raised from eggs which had been irradiated at the vegetal hemisphere with UV (9300 erg/mm2) at the 2-cell stage. In R. japonica about 70% of the larvae at stage I from the pressed and UV-irradiated eggs were germ cell free, but at a stage immediately after metamorphosis all animals had at least some germ cells, although their gonads often were extremely small and poorly differentiated. When male animals matured sexually, many of them had abnormal gonads. However, all of them were shown by artificial means to be capable of fertilization. In the nonpressed and irradiated group, no larvae were germ cell free and the animals immediately after metamorphosis showed nearly normal gonadal differentiation except for the presence of a few degenerate oocytes in the ovaries. The results in R. brevipoda were basically similar to those in R. japonica. In both species, sex ratios were determined at two stages, the first immediately after metamorphosis and the other when the animals matured, as based on gonad morphology and histology and on external sexually dimorphic characters as well. Sex ratios at these two stages in frogs from the pressed and irradiated eggs differed markedly in R. brevipoda. The ratio was normal at metamorphosis but high M/F ratios occurred when animals became mature. That sex reversal took place in this species as well as in R. japonica (in which sex-ratio deviation was not statistically significant) was supported by the sex ratios of the progenies of these supernumerary males.

  9. Identification and characterisation of a novel antimicrobial polypeptide from the skin secretion of a Chinese frog (Rana chensinensis).

    PubMed

    Jin, Li L; Song, Shu S; Li, Qiang; Chen, Yu H; Wang, Qiu Y; Hou, Sheng T

    2009-06-01

    Amphibians secrete small antimicrobial polypeptides from their skin that have been explored as alternatives to conventional antibiotics. In this study, mass spectrometry was used to identify and characterise protein secretions from the skin of a Chinese frog, Rana chensinensis. The skin of this kind of frog has been used in traditional Chinese medicine for centuries as a remedy against inflammation. A novel antimicrobial peptide was identified and the characteristics of this peptide were analysed using far-ultraviolet circular dichroism. When dissolved in aqueous solution, the peptide displayed a high level of random coil structure, in contrast to a more ordered alpha-helical structure when dissolved in 50% trifluoroethanol. Functional studies showed that this peptide has potent antimicrobial activity both against Gram-positive and Gram-negative bacteria and has extremely low haemolytic activity to human red blood cells. Taken together, these studies suggest that this novel peptide can be further developed as an antimicrobial agent.

  10. The function of fat bodies in relation to the hypothalamo-hypophyseal-gonadal axis in the frog, Rana esculenta.

    PubMed

    Chieffi, G; Rastogi, R K; Iela, L; Milone, M

    1975-08-18

    In this study the authors have tried to furnish experimental support for the importance of fat bodies in the normal functioning of the hypothalamo-hypophyseal-gonadal system of the male frog, Rana esculenta. These experiments have shown a hypothalamo-hypophyseal control of the mobilization of fat body contents, directly involved in the control of testicular activity. Furthermore it is proposed that the fat body contents are released into the testis through direct vascular contacts between the two organs. We suggest that the A1 cells (lactotrophs) and/or B2 cells (FSH-gonadotrops) of the pars distalis gonadotropins are incapable of stimulating the testis in the absence of fat bodies. In the light of these results a scheme has been put forward showing the position of fat bodies in the hypothalamo-hypophyseal-gonadal axis of the frog.

  11. Influence of sex and breeding condition on microhabitat selection and diet in the pig frog Rana grylio

    SciTech Connect

    Lamb, T.

    1984-04-01

    A 14-month study was conducted on the pig frog (Rana grylio) in SW Georgia. This species has a prolonged breeding season as males call from late March to September. Mature spermatozoa were present in the testes year-round, though seasonal testicular changes were detectable with spermatogenesis reaching a peak in June. Females contained mature ova from April through July and development of the following year's ova began in August. Stomachs of 122 postlarval specimens contained mainly anthropods. Coleoptera, Decopoda (Procambarus) and Odonata accounted for the majority of individual prey items, constituting 24.3, l9.8 and 11.9%, respectively. Intersexual dietary differences were apparent among adult frogs during the breeding season; variation in diet was strongly influenced by behavioral and habitat differences at this time.

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

    PubMed

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

    2015-05-01

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

  13. Environmental stress responsive expression of the gene li16 in Rana sylvatica, the freeze tolerant wood frog.

    PubMed

    Sullivan, Katrina J; Storey, Kenneth B

    2012-06-01

    Wood frogs (Rana sylvatica) can endure weeks of subzero temperature exposure during the winter with up to 65% of their body water frozen as extracellular ice. Associated with freezing survival is elevated expression of a number of genes/proteins including the unidentified gene, li16, first described in liver. The current study undertakes a broad analysis of li16 expression in response to freezing in 12 tissues of wood frogs as well as expression responses to anoxia and dehydration. Transcript levels of li16 increased significantly after 24h freezing (at -2.5 °C) demonstrating increases of approximately 3-fold in testes, greater than 2-fold in heart, ventral skin and lung, and over 1.5-fold in brain, liver and hind leg muscle as compared to unfrozen controls at 5 °C. Increased li16 transcript levels in brain, muscle and heart were mirrored by elevated Li16 protein in frozen frogs. Significant upregulation of li16 in response to both anoxia and dehydration (both components of freezing) was demonstrated in brain, kidney and heart. Overall, the results indicate that Li16 protein has a significant role to play in cell/organ responses to freezing in wood frogs and that its up-regulation may be linked with oxygen restriction that is a common element in the three stress conditions examined.

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

    PubMed

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

    2007-11-01

    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. The CART peptide, when injected into the venous sinus, significantly and reproducibly increased the force of frog heart contractions by up to 33.0 +/- 6.4% during the first 15 min after its application but did not influence the chronotropic activity of the frog heart. The positive inotropic effect was entirely blocked by prazosin, pertussis toxin, R(p)-adenosine 3',5'-cyclic monophosphorothioate, autosauvagine 30 or metyrapone, as well as by extirpation of the pituitary gland, functional elimination of the inter-renal glands and long-lasting starvation, and was not observed on isolated heart preparations. Propranolol and double pithing were without significant effect on this phenomenon. It was concluded that: (i) CART peptide, administered to frogs in vivo, increases the force of heart contractions; (ii) this effect of the peptide is exerted via activation of the hypothalamic-pituitary-inter-renal gland axis through a corticoliberin-sensitive mechanism; (iii) CART augments the pumping function of the heart via a corticosteroid-dependent potentiation of myocardial alpha(1)-adrenoreceptors signalling; and (iv) prolonged food deprivation abolishes the positive inotropic effect of CART, suggesting the participation of endogenous CART in the physiological adaptation of the circulatory system to limitations of energy consumption.

  15. Landscape resistance to frog movements

    USGS Publications Warehouse

    Mazerolle, M.J.; Desrochers, A.

    2005-01-01

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

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

    USGS Publications Warehouse

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

    2003-01-01

    The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median <25 m). Intervals spent on land were again brief during mid/late winter (median = 1-4 days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( <300 m) were completed in 1-3 days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the

  17. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica)

    PubMed Central

    Gerber, Victoria E.M.; Wijenayake, Sanoji

    2016-01-01

    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. PMID:27042393

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

    PubMed

    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.

  19. Changes in formaldehyde-induced fluorescence of the hypothalamus and pars intermedia in the frog, Rana temporaria, following background adaptation.

    PubMed

    Prasada Rao, P D

    1982-01-01

    Adaptation of the frog, Rana temporaria, to a white background for 12 hr has resulted in an intense formaldehyde-induced fluorescence (FIF) in the neurons of the preoptic recess organ (PRO), paraventricular organ (PVO), nucleus infundibularis dorsalis (NID) and their basal processes permitting visualization of the PRO- and PVO-hypophysial tracts that extend into the median eminence (ME) and pars intermedia (PI); the FIF is reduced in all the structures by 3 days. In frogs adapted to a black background, for 12 hr and 3 days, there was a general reduction in the FIF of the PRO neurons and PRO-hypophysial tract. By 12 hr black background adaptation, the PVO/NID neurons and only their adjacent basal processes show FIF which was sharply reduced by 3 days, making the PVO-hypophysial tract undetectable. In the PI fibers the fluorescence was more intense in black-adapted frogs than in white-adapted ones at both the intervals studied. The simultaneous changes in the FIF of the hypothalamic nuclei, tracts and PI suggest that the PRO and PVO/NID neurons participate in PI control through release of neurotransmitter(s) at the axonal ends.

  20. Acid-shock, aluminium, and presence of Sphagnum aurantiacum: effect on embryological development in the common frog, Rana temporaria and the moor frog, Rana arvalis

    SciTech Connect

    Olsson, M.; Hogstrand, C.; Dahlberg, A.; Berglind, S.A.

    1987-07-01

    During the last two decades, several effects of acidification have been shown, e.g., enhanced leaching of metals from sediments and soil. Furthermore, an increased growth of Sphagnum aurantiacum frequently occurs in acidified waters. The aim of the present study is to investigate some effects of acidification on the embryological development on two Anurans. The toxicity of aluminium is thought to vary with pH. The highest toxicity of aluminium in the hydroxyl form have been found at pH 5. In the present study a laboratory experiment was performed to investigate the toxicity of Al to frog embryos in water with pH 5.0. In acidified waters Sphagnum and especially S. aurantiacum, is competitive and quickly become established. It has been indicated that frog spawn deposited on Sphagnum show an unusually high mortality and questions have been raised if Sphagnum reinforces the detrimental effects of acidification on Anuran reproduction.

  1. Expression of P450arom and Estrogen Receptor Alpha in the Oviduct of Chinese Brown Frog (Rana dybowskii) during Prehibernation

    PubMed Central

    Weng, Ji; Liu, Yuning; Xu, Ying; Hu, Ruiqi; Zhang, Haolin; Sheng, Xia; Watanabe, Gen; Taya, Kazuyoshi; Weng, Qiang; Xu, Meiyu

    2015-01-01

    One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed that there were significant differences in both oviductal weight and size with values markedly higher in prehibernation than in the breeding period. P450arom was observed in stromal tissue in both the breeding period and prehibernation. ERα was expressed in stromal tissue and epithelial cells in both periods, whereas ERβ could not be detected. The mean protein and mRNA levels of P450arom and ERα were significantly higher in prehibernation as compared to the breeding period. Besides, oviductal content of 17β-estradiol was also higher in prehibernation than in the breeding period. These results suggested that estrogen may play autocrine/paracrine roles mediated by ERα in regulating the oviductal hypertrophy during prehibernation. PMID:25802518

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

    PubMed

    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.

  3. Juvenile frogs compensate for small metamorph size with terrestrial growth: Overcoming the effects of larval density and insecticide exposure

    USGS Publications Warehouse

    Boone, M.D.

    2005-01-01

    I reared four species of anurans (Rana sphenocephala [Southern Leopard Frog], Rana blairi [Plains Leopard Frog], Rana clamitans [Green Frog], and Bufo woodhousii [Woodhouse's Toad]) for seven to 12 months in small, outdoor terrestrial enclosures (1 x 2 m) to examine the consequences of larval competition (via density) and contaminant exposure (via the insecticide carbaryl). I added six Rana clamitans, eight Rana sphenocephala, eight Rana blairi, and 10 Bufo woodhousii to terrestrial enclosures shortly after metamorphosis and recaptured them during the following spring. All anurans from low-density ponds were significantly larger than those from high-density ponds, but these size differences did not significantly affect survival to or size at spring emergence. However, R. sphenocephala, R. blairi, and R. clamitans that survived to spring had been larger at metamorphosis on average than those that did not survive; in contrast, B. woodhousii that survived the winter were smaller at metamorphosis on average than those that did not survive. Carbaryl exposure affected mass at metamorphosis of R. clamitans and B. woodhousii that were added to enclosures, but this difference disappeared or did not increase by spring emergence. Overall, exposure to carbaryl during the larval period did not have any apparent effects on survival or growth during the terrestrial phase. In my study, anurans were able to offset small size at metamorphosis with terrestrial growth, although there was a trend of reduced overwinter survival for ranid species that metamorphosed at a smaller size. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  4. [Analysis of helminthofauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) at their joint habitation].

    PubMed

    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.

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

    PubMed Central

    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. PMID:26370166

  6. Growth, size and age at maturity of the agile frog (Rana dalmatina) in an Iberian Peninsula population.

    PubMed

    Sarasola-Puente, Vanessa; Gosá, Alberto; Oromí, Neus; Madeira, María José; Lizana, Miguel

    2011-06-01

    The mean age of a population of agile frogs (Rana dalmatina) from the Iberian Peninsula was estimated using mark and recapture and skeletochronology. Life-history parameters, including growth rate, body length, age and size at maturity, sexual dimorphism and longevity, were studied. The regression between age and snout-vent length (SVL) was highly significant in both sexes. Males reached sexual maturity at two years of age, although sometimes they can reach it at only one year of age. The average SVL at maturity was 51.75 mm (standard error (SE)=0.71; n=45). Females reached sexual maturity at two years of age with an average SVL of 62.14 mm (SE=2.20; n=14). A subset of the female population reached sexual maturity at three years of age. Growth was rapid until sexual maturity was reached. There was an overlap of SVL between different age classes. Growth was continuous, fulfilling the conditions of Von Bertalanffy's model. The growth coefficient (K) was 0.840 in males and 0.625 in females. The maximum SVL was greater in females (73.00 mm) than in males (59.50mm). Sexual dimorphism was significantly biased towards females in all age classes. The maximum longevity observed was 6 years in females and 8 years in males. Management strategies for agile frogs should take into account factors such as these life-history characteristics.

  7. Different responses of biochemical markers in frogs (Rana ridibunda) from urban and rural wetlands to the effect of carbamate fungicide.

    PubMed

    Falfushinska, Halina I; Romanchuk, Liliya D; Stolyar, Oksana B

    2008-09-01

    Laboratory studies were conducted to determine the effects of carbamate fungicide TATTU (mixture of propamocarb and mancozeb, 0.091 mg L(-1)) on biochemical markers of exposure in Rana ridibunda from clean (reference) and polluted sites. The untreated animals from the polluted site had lower Cu,Zn- and Mn-superoxide dismutase (SOD) and acetylcholinesterase activity, the levels of lipid peroxidation products (TBARS) and protein carbonyls in the liver and vitellogenin-like proteins (Vtg-LP) in the serum, but higher levels of glutathione in the liver in comparison with untreated frogs from the reference site. Catalase activity, superoxide anion and metallothionein levels were the same in both groups. The animals from two sites demonstrate different response on the effect of TATTU during 14 days. In the frogs from polluted site the oxidative damage (the decrease of Mn-SOD activity, lipids and protein oxidative destruction), neurotoxicity (depletion of acetylcholinesterase activity), and endocrine disruption (increase of Vtg-LP level) were revealed. On the other hand, the part of the indices in the animals from the reference site was unchanged after the treatment and the level of metallothionein was elevated demonstrating the satisfactory ability for the adaptation to unfavourable conditions.

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

    PubMed Central

    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

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

    PubMed

    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.

  10. Species boundaries, phylogeography, and conservation genetics of the red-legged frog (Rana aurora/draytonii) complex

    USGS Publications Warehouse

    Shaffer, H. Bradley; Fellers, Gary M.; Voss, S. Randal; Oliver, J. C.; Pauly, Gregory B.

    2004-01-01

    The red-legged frog, Rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. It is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the US Endangered Species Act. We present the results of a survey of 50 populations of red-legged frogs from across their range plus four outgroup species for variation in a phylogenetically informative, ∼400 base pairs (bp) fragment of the mitochondrial cytochromeb gene. Our mtDNA analysis points to several major results. (1) In accord with several other lines of independent evidence, aurora and draytonii are each diagnosably distinct, evolutionary lineages; the mtDNA data indicate that they do not constitute a monophyletic group, but rather that aurora and R. cascadae from the Pacific northwest are sister taxa; (2) the range of thedraytonii mtDNA clade extends about 100 km further north in coastal California than was previously suspected, and corresponds closely with the range limits or phylogeographical breaks of several codistributed taxa; (3) a narrow zone of overlap exists in southern Mendocino County between aurora and draytonii haplotypes, rather than a broad intergradation zone; and (4) the critically endangered population of draytonii in Riverside County, CA forms a distinct clade with frogs from Baja California, Mexico. The currently available evidence favours recognition of auroraand draytonii as separate species with a narrow zone of overlap in northern California.

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

    PubMed

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

    2010-09-02

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

  12. A study of ovarian follicular kinetics, oviduct, fat body, and liver mass cycles in laboratory-maintained Rana cyanophlyctis in comparison with wild-caught frogs.

    PubMed

    Pancharatna, K; Saidapur, S K

    1992-11-01

    Ovarian follicular dynamics and fluctuations in fat body, oviducal, and liver masses were studied in captive Rana cyanophlyctis in comparison with wild-caught frogs, sampled at monthly intervals over a period of 12 months. In both the captive and wild-caught frogs first growth phase (FGP) and second growth phase (SGP) or vitellogenic oocytes were produced throughout the period examined; however, changes in ovarian and oviducal weights were less marked in the former group. In the captive frogs SGP oocyte production was reduced by 50%, and, maximum ovarian weight and SGP oocyte number were attained 2-3 months earlier than in wild-caught controls. The FGP oocyte pool in laboratory-maintained frogs, however, was comparable with that of the corresponding wild-caught frogs. Captivity caused a threefold increase in atresia and reduced the number of oocytes reaching SGP. The depletion of fat stores in fat bodies during the later phases of captivity suggests that the deposition of lipids into oocytes (for SGP) was given priority over storage in the fat bodies. The low oviducal weights of captive frogs was correlated with a reduced number of SGP oocytes, which are the source of estrogen. On the other hand, liver weight remained high, indicating adequate hepatic vitellogenin synthesis. Possible reduction in its output was not detected, possibly due to the reduced number of follicles reaching SGP. The findings indicate that stress of captivity decreases gonadotrophins and estrogen levels. Oviducal growth is reduced in captive frogs.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  14. Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

    PubMed

    Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

    2010-08-01

    The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

  15. [Characteristics of the phase-dependent vagus effects in the heart of the frog Rana temporaria and of the cod Gadus morhua].

    PubMed

    Kopylova, G N; Sokolova, N A; Samonina, G E; Krupnova, E P

    1987-01-01

    In experiments on the heart of the cod Gadus morhua and frog Rana temporaria in situ, studies have been made of changes in the heart rate induced by stimulation of the vagal nerve by single brief bursts delivered at various intervals after P wave of the ECG. Certain differences were found in changes of the heart rate between these animals. In the cod, maximum chronotropic effect was equal to 65% of the duration of initial cardiac cycle, the latency of this effect being equal to 290 ms; in the frog, corresponding figures were 12-13% and approximately 940 ms. The duration of negative chronotropic effect in the heart of the cod was equal to 700 ms, that of the frog--to 2.700 ms. Functional role of these differences is discussed in relation to the problem of the development of parasympathetic regulation of the heart rate in phylogenesis of vertebrates.

  16. Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    USGS Publications Warehouse

    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.

  17. Ameliorative effects of sodium chloride on acute copper toxicity among Cope's gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos.

    PubMed

    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.

  18. Cold acclimation-induced up-regulation of the ribosomal protein L7 gene in the freeze tolerant wood frog, Rana sylvatica.

    PubMed

    Wu, Shaobo; De Croos, J N Amritha; Storey, Kenneth B

    2008-11-15

    Natural freezing survival by the wood frog, Rana sylvatica, involves multiple organ-specific changes in gene expression. The present study used differential display PCR to find cold-responsive genes in wood frog skin. A cDNA was retrieved from skin that was in higher amounts in cold- versus warm-acclimated frogs. The cDNA was used to probe a wood frog liver cDNA library and retrieve a long sequence that, after the further application of 5'RACE, was shown to encode the full sequence of the ribosomal large subunit protein 7 (RPL7) (GenBank accession number AF175983). Wood frog RPL7 contained 246 amino acids and shared 90% identity with Xenopus laevis RPL7, 82-83% with chicken and zebrafish homologues, and 79% with mammalian RPL7. Multiple binding domains found in human RPL7 showed differing degrees of conservation in the frog protein. Transcript levels of rpl7 were elevated up to 4-fold in skin of cold-acclimated frogs as compared with warm-acclimated animals. Organ-specific responses by rpl7 transcripts also occurred when frogs were given survivable freezing exposures. Transcripts rose by 1.8-3.3 fold in brain and skeletal muscle during freezing but were unaffected in central organs such as liver and heart. Up-regulation of rpl7 also occurred in brain of anoxia-exposed frogs and RPL7 protein levels increased strongly in heart under both freezing and dehydration stresses. Cold- and freezing-responsive up-regulation of the rpl7 gene and RPL7 protein in selected organs suggests that targeted changes in selected ribosomal proteins may be an integral part of natural freeze tolerance.

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

    PubMed Central

    Muir, A P; Biek, R; Thomas, R; Mable, B K

    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. 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 QST–FST 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. PMID:24330274

  20. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria).

    PubMed

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

    2016-06-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpoles collected from ponds with differing water quality. Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site. Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination. Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation.

  1. Identification and characterization of a novel freezing inducible gene, li16, in the wood frog Rana sylvatica.

    PubMed

    McNally, J Dayre; Wu, Shao-Bo; Sturgeon, Christopher M; Storey, Kenneth B

    2002-06-01

    The wood frog Rana sylvatica survives for weeks during winter hibernation with up to 65% body water frozen as ice. Natural freeze tolerance includes both seasonal and freeze-induced molecular adaptations that control ice formation, deal with long-term ischemia, regulate cell volume changes, and protect macromolecules. This report identifies and characterizes a novel freeze-inducible gene, li16, that codes for a protein of 115 amino acids. Northern blot analysis showed that li16 transcript levels rose quickly during freezing to reach levels 3.7-fold higher than control values after 24 h; immunoblotting showed a parallel 2.4-fold rise in Li16 protein. Regulatory influences on gene expression were assessed. Nuclear runoff assays confirmed that freezing initiated an increase in the rate of li16 transcription, and analysis of signal transduction pathways via in vitro incubation of liver slices implicated a cGMP-mediated pathway in li16 expression. Gene and protein expression in liver was also strongly stimulated by anoxia exposure, whereas the gene was less responsive to dehydration stress. The strong response of li16 to both freezing and anoxia, and the rapid down-regulation of the gene when oxygen was reintroduced, suggest that the Li16 protein may play a role in ischemia resistance during freezing.

  2. Sodium arsenite induced changes in survival, growth, metamorphosis and genotoxicity in the Indian cricket frog (Rana limnocharis).

    PubMed

    Singha, Utsab; Pandey, Neelam; Boro, Freeman; Giri, Sarbani; Giri, Anirudha; Biswas, Somava

    2014-10-01

    Arsenic contamination of the environment is a matter of great concern. Understanding the effects of arsenic on aquatic life will act as biological early warning system to assess how arsenic could shape the biodiversity in the affected areas. Rapid decline in amphibian population in recent decades is a cause of major concern. Over the years, amphibians have been recognized as excellent bio-indicators of environmental related stress. In the present study, we examined the toxic and genotoxic effects of sodium arsenite in the tadpoles of the Indian cricket frog (Rana limnocharis). Sodium arsenite at different concentrations (0, 50, 100, 200 and 400 μg L(-1)) neither induced lethality nor significantly altered body weight at metamorphosis. However, it accelerated the rate of metamorphosis at higher concentrations, reduced body size (snout-vent length) and induced developmental deformities such as loss of limbs. Besides, at concentration ranges between 100 and 400 μg L(-1), sodium arsenite induced statistically significant genotoxicity at 24, 48, 72 and 96 h of the exposure in a concentration-dependent manner. However, it did not show time effects as the highest frequency was found between 48 and 72 h which remained steady subsequently. The genotoxicity was confirmed by comet assay in the whole blood cells. These findings suggest that arsenic at environmentally relevant concentrations has significant sub-lethal effects on R.limnocharis, which may have long-term fitness consequence to the species and may have similar implications in other aquatic life too.

  3. Evolutionary dynamics of a rapidly receding southern range boundary in the threatened California red-legged frog (Rana draytonii)

    USGS Publications Warehouse

    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.

  4. Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis)

    PubMed Central

    Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

    2014-01-01

    Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840

  5. Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa)

    PubMed Central

    KNAPP, Roland A.; BOIANO, Daniel M.; VREDENBURG, Vance T.

    2007-01-01

    The mountain yellow-legged frog (Rana muscosa) was once a common inhabitant of the Sierra Nevada (California, USA), but has declined precipitously during the past century due in part to the introduction of nonnative fish into naturally fishless habitats. The objectives of the current study were to describe (1) the effect of fish removal from three lakes (located in two watersheds) on the small, remnant R. muscosa populations inhabiting those lakes, and (2) the initial development of metapopulation structure in each watershed as R. muscosa from expanding populations in fish-removal lakes dispersed to adjacent habitats. At all three fish-removal lakes, R. muscosa population densities increased significantly following the removal of predatory fish. The magnitude of these increases was significantly greater than that observed over the same time period in R. muscosa populations inhabiting control lakes that remained in their natural fishless condition. Following these population increases, R. muscosa dispersed to adjacent suitable (but unoccupied) sites, moving between 200 and 900 m along streams or across dry land. Together, these results suggest that large-scale removal of introduced fish could result in at least partial reversal of the decline of R. muscosa. Continued monitoring of R. muscosa at the fish-removal sites will be necessary to determine whether the positive effects of fish eradication are sustained over the long-term, especially in light of the increasingly important role played by an emerging infectious disease (chytridiomycosis, caused by Batrachochytrium dendrobatidis) in influencing R. muscosa populations. PMID:17396156

  6. Conservation genetics of evolutionary lineages of the endangered mountain yellow-legged frog, Rana muscosa (Amphibia: Ranidae), in southern California

    USGS Publications Warehouse

    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.

  7. Multiple invasions of the Ryukyu Archipelago by Oriental frogs of the subgenus Odorrana with phylogenetic reassessment of the related subgenera of the genus Rana.

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Ota, Hidetoshi; Tanaka-Ueno, Tomoko

    2005-12-01

    The genus Rana, notably diversified in Oriental regions from China to Southeast Asia, includes a group of cascade frogs assigned to subgenera Odorrana and Eburana. Among them, R. ishikawae and the R. narina complex represent the northernmost members occurring from Taiwan to the Ryukyu Archipelago of Japan. Relationships of these frogs with the continental members, as well as the history of their invasions to islands, have been unclear. The taxonomic status of Odorrana and related genera varies among authors and no phylogenetic reassessment has been done. Using partial sequences of mitochondrial 12S and 16S rRNA genes, we estimated phylogenetic relationships among 17 species of the section Hylarana including Odorrana and Eburana, and related species from the Ryukyus, Taiwan, China, Thailand, Malaysia, and Indonesia. We estimate that (1) Odorrana is monophyletic and encompasses species of Eburana and R. hosii, which is now placed in Chalcorana, (2) the ancestor of R. ishikawae separated from other Rana in the middle to late Miocene prior to its entry to the Ryukyu Archipelago, (3) the ancestor of the R. narina complex later diversified in continental Asia, and invaded the Ryukyu Archipelago through Taiwan, (4) the R. narina complex attained its current distribution within the Ryukyus through niche segregations, and (5) vicariance of R. hosii between Malay Peninsula and Borneo occurred much later than the divergence events in the R. narina complex. Current subgeneric classification of Rana, at least of Southeast Asian members, requires full reassessment in the light of phylogenetic relationships.

  8. Alterations of biochemical parameters in malformed Indian rice frogs, Rana limnocharis from Southern Taiwan.

    PubMed

    Chiu, Yuh-Wen; Wang, Shu-Yin; Wu, Jui-Pin; Huang, Da-Ji

    2011-11-01

    The purpose of this study is to investigate the factors that cause malformed frogs in upstream Kaoping river (KP site) and Tungkang river (T site) of Southern Taiwan. In this experiment, the activities of monooxygenase (MO), glutathione-S-transferase (GST), acetylcholinesterase (AchE) as well as the concentration of vitellogenin (Vg) in the liver were measured. Results show that activities of MO, GST and AchE, and Vg levels in normal frogs (male/female) were 0.09 +/- 0.02/0.09+/-0.01 deltaA min(-1) mg(-1) protein, 0.12 +/- 0.04/0.13 +/- 0.04 deltaA min(-1) mg(-1) protein, 6.13 +/- 2.69/6.01 +/- 2.09 U mg(-1) protein and 0.87 +/- 0.42/2.18 +/- 0.50 microg mg(-1) protein, respectively. Activities of MO, GST and AchE, and Vg levels in malformed frogs (male/female) were 0.15 +/- 0.04/0.21 +/- 0.07 deltaA min(-1) mg(-1) protein, 0.27 +/- 0.08/0.30 +/- 0.12 deltaA min(-1) mg(-1) protein, 4.59 +/- 2.71/5.19 +/- 3.74 U mg(-1) protein and 1.46 +/- 0.61/3.15 +/- 0.88 microg mg(-1) protein, respectively in KP site, and were 0.16 +/- 0.69/0.1 +/- 80.07 deltaA min(-1) mg(-1) protein, 0.21 +/- 0.07/0.24 +/- 0.08 deltaA min(-1) mg(-1) protein, 5.13 +/- 4.58/3.94 +/- 1.33 U mg(-1) protein and 2.23 +/- 1.47/4.11 +/- 1.63 microg mg(-1) protein, respectively in T site. These results indicate that male and female malformed frogs in both rivers upstream are found with higher activities. No significant difference in AchE activity was found between normal and malformed frogs in this investigation. It is therefore reasonable to speculate that the organic chemicals released from agricultural activities are presumable the main factors that lead to the malformation of frogs.

  9. Hemodynamic consequences of delayed ventriculoconal conduction in the frog Rana catesbeiana.

    PubMed

    Liberthson, R R; Szidon, J P; Bharati, S; Lev, M; Fishman, A P

    1975-10-01

    We investigated the function of the conus arteriosus in the bullfrog Rana catesbeiana using a combination of anatomical and physiological techniques. Although there is a normal delay in ventriculoconal conduction and we could induce a spectrum of ventriculoconal conduction disturbances by manipulating the region of the ventriculoconal junction, we found no histological evidence of specialized conducting myocardial tissue in this region. The performance of the conus arteriosus was explored during various disturbances of ventriculoconal conduction and also during hemodynamic disturbances produced by hemorrhage and afterloading. The conus was found to contribute little to forward flow under ordinary circumstances, but its contribution increased greatly during bleeding or partial occlusion of the truncus. In contrast to the conclusion of others, no evidence could be adduced to support the idea that the conus serves as a depulsating chamber. Disparities in previous reports concerning the operation of the conus as a booster pump are attributed to special experimental circumstances.

  10. Fat body involvement in vitellogenin fate in the green frog, Rana esculenta.

    PubMed

    Varriale, B; Di Matteo, L; Minucci, S; Pierantoni, R; Chieffi, G

    1988-01-01

    1. Since, in Rana esculenta, fat bodies contain vitellogenin, the present study was performed in order to determine whether or not fat bodies are involved in the fate of vitellogenin. 2. The experiment of November shows that fat body excision provokes plasma vitellogenin increase even in animals treated with estradion-17 beta + pituitary crude homogenate (as compared with relative control). The same picture has been shown in the April experiment. 3. The result on protein-bound phosphate in ovaries from the April experiment has shown that fat body extirpation causes a decrease of protein-bound phosphate in the ovary. 4. This results indicates that fat bodies play an important role in sequestrating circulating vitellogenin by the ovary.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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. Analysis of skin and secretions of Dybowski's frogs (Rana dybowskii) exposed to Staphylococcus aureus or Escherichia coli identifies immune response proteins.

    PubMed

    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.

  14. Input and output characteristics of collision avoidance behavior in the frog Rana catesbeiana.

    PubMed

    Yamamoto, Keisuke; Nakata, Maki; Nakagawa, Hideki

    2003-01-01

    Input and output characteristics of collision avoidance behavior in the bullfrog were examined using computer graphics to model a looming stimulus. The means of time-to-collision of avoidance behavior in response to looming visual stimuli approaching at a velocity of either 2 or 4 m/s were significantly different (t141) = 7.93, p < 0.05). On the other hand, mean threshold sizes of visual stimuli triggering avoidance behavior were not significantly different in either case (t201) = 0.54, p > 0.05). Furthermore, we showed that the mean threshold sizes changed in a predictable manner depending on the distance between the displayed stimulus and the animal. These results strongly suggest that the frog displays collision avoidance behavior when the visual angle of a looming object reaches a constant value (about 20 degrees ). The mean maximum velocities of the avoidance behavior in response to the two visual stimuli were not significantly different (t198) = 1.44, p > 0.05). However, we found that the frog could control the velocity depending on the location of an approaching object in its dorsal visual field. Finally, we demonstrated that habituation significantly affected the mean probability of avoidance behavior occurrence (ANOVA, at 2 m/s, F(2,15) = 14.25; at 4 m/s, F(2,15) = 13.35, p < 0.05), but not those of time-to-collision, threshold size and maximum velocity (ANOVA, at 2 m/s, F(2,13) = 0.07, F(2,14) = 0.46 and F(2,14) = 0.70, respectively; at 4 m/s, F(2,15) = 0.50, F(2,14) = 0.68 and F(2,14) = 0.41, respectively, p > 0.05). Thus, frog collision avoidance behavior seems to have an all or none-like property.

  15. Spatio-temporal Dynamics of Pond Use and Recruitment in Florida Gopher Frogs (Rana Capito aesopus)

    SciTech Connect

    Greenberg, C.H.

    2000-05-16

    We examined spatio-temporal dynamics of the Florida Gopher frog breeding and juvenile recruitment. Ponds were situated in a hardwood or pine-savanna matrix of upland forest. Movement was monitored from 1994-1999. Adult pond use was low but relatively constant. Juvenile recruitment was higher in the upland savanna matrix. Body size was negatively correlated with the number of juveniles exiting the pond in only one year suggesting intraspecific competition is one of many factors. Most immigration occurred in May through August and was unrelated to rainfall.

  16. [Peculiarities of Ca2+ regulation of functional activity of myocardium of frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2008-01-01

    To elucidate role of intra- and extracellular Ca2+ in regulation of rhythm and strength of frog heart contractions, there were studied ECC and isometric contraction of myocardium preparations in response to verapamil, adrenaline, and blockers of alpha- and beta-adrenoreceptors. It has been shown that after an intramuscular injection of verapamil (6 mg/kg), bradycardia develops, the heart rate (HR) decreasing by 50-70 %. Further, the cardiac arrest occurred; however, administration to the animals of adrenaline (100 mg/kg) restored the cardiac rhythm for a short while. After an intramuscular injection of adrenaline at doses of 0.1-10 mg/kg, no essential changes were observed in the potential action amplitude and HR; an increase of the administered adrenalin concentration to 100 mg/kg was not accompanied by the cardiac rhythm stimulation, as this takes place in homoiothermal animals and human; on the contrary, an essential HR deceleration was revealed. Phentolamine (5 mg/kg) gradually decelerated HR rhythm by 32-45 %. The potential amplitude changed insignificantly. A subsequent intracardiac injection of adrenaline (100 mg/kg) on the background of block of alpha-adrenoreceptors produced acceleration of the rhythm (by 13-21%) and fall of the electrogram amplitude. These results can indicate that in the frog heart, phentolamine interacts predominanty with alpha-adrenoreceptors. An intracardiac administration of propranolol (1 mg/kg) to frogs promoted inhibition of beta-adrenergic receptors and produced a gradual cardiac rhythm deceleration. In experiments on assessment of verapamil effect on the character of contractions this preparation at a concentration of 150 microM was established to produce a significant dosedependent decrease of the contraction strength. A rise of verapamil concentration in the sample to 200 microM led to a decrease of the amplitude, on average, by 68-70 % and in individual preparations -- by 80-85 %; however, administration into the sample of

  17. Effect of mercuric chloride on fertilization and larval development in the River Frog, Rana heckscheri (Wright) (Anura: Ranidae)

    SciTech Connect

    Punzo, F. )

    1993-10-01

    Previous investigations have indicated that heavy metals such as copper, cadmium, lead and mercury can act as systemic toxicants in many species of wildlife. Although numerous studies have emphasized the effects of metals and pesticides on metabolism, growth, survivorship, neural processes and reproduction in a number of taxa, little information is available on the effects of sublethal concentrations of metals on the reproductive physiology of amphibians. Industrial processes and mining activities can release substantial concentrations of heavy metals such as mercury into aquatic habitats. Since most amphibians have obligate aquatic larval stages, they are exposed to pollutants discharged into the aquatic environment. Amphibians can act as accumulators of heavy metals and their larval stages are useful indicators of pollution levels in the field. What little data are available, indicate that metals can significantly reduce viability in amphibians through their actions on metabolism, development and gametogenesis. The recent concerns over worldwide declines in amphibian populations and the susceptibility of amphibian populations to environmental toxicants, led me to assess the effect of mercuric chloride, one of the most common and persistent toxicants in aquatic environments, on fertilization and larval development in the river frog, Rana heckscheri (Wright). Although there is some information on fish, very little data are available on the effects of mercury on fertilization in amphibians generally, and no published data exist for R. heckscheri. This species is a conspicuous component of the aquatic fauna of parts of the southeastern United States where mercury levels have increased significantly over the last two decades. 22 refs., 2 tabs.

  18. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis

    PubMed Central

    Price, Stephen J.; Garner, Trenton W. J.; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H.; Moore, Karen; Griffiths, Amber G. F.

    2015-01-01

    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. PMID:26111016

  19. Autonomic regulation of mucociliary transport rate in the oesophagus of the frog, Rana temporaria.

    PubMed Central

    Morley, J; Sanjar, S

    1984-01-01

    Transport of lead particles along the mucosal surface of the frog oesophagus has been measured by direct observation with the aid of video recording. Electrical stimulation of the vagus nerve increased the rate of particle transport. This acceleration was suppressed by atropine or by hexamethonium. Acetylcholine and other parasympathomimetic agents accelerated particle transport rate. Such acceleration was abolished by atropine. Nicotine increased the rate of particle transport and this effect was suppressed by hexamethonium or by atropine. Atropine did not significantly alter basal particle transport rate. Neither basal particle transport rate nor the response to vagal nerve stimulation were affected by eserine. Adrenaline, noradrenaline or isoprenaline did not affect basal particle transport rate. Adrenaline or noradrenaline were without effect on the increased particle transport rate due to electrical stimulation of the vagus. PMID:6332901

  20. Epidermal laser stimulation of action potentials in the frog sciatic nerve

    NASA Astrophysics Data System (ADS)

    Jindra, Nichole M.; Goddard, Douglas; Imholte, Michelle; Thomas, Robert J.

    2010-01-01

    Measurements of laser-stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) are made using two infrared lasers. The dorsal sides of the frog's hind limbs are exposed to short-pulsed 1540- and 1064-nm wavelengths at three separate spot sizes: 2, 3, and 4 mm. Energy density thresholds are determined for eliciting an action potential at each experimental condition. Results from these exposures show similar evoked potential thresholds for both wavelengths. The 2-mm-diam spot sizes yield action potentials at radiant exposure levels almost double that seen with larger beam sizes.

  1. Nitrite modulates contractility of teleost (Anguilla anguilla and Chionodraco hamatus, i.e. the Antarctic hemoglobinless icefish) and frog (Rana esculenta) hearts.

    PubMed

    Cerra, M C; Angelone, T; Parisella, M L; Pellegrino, D; Tota, B

    2009-07-01

    Being the largest form of intravascular and tissue storage of nitric oxide (NO) and a signalling molecule itself, the nitrite anion (NO(2)(-)) has emerged as a key player in many biological processes. Since the heart is under an important NO-mediated autocrine-paracrine control, in mammals the cardiac effects of nitrite are under intensive investigation. In contrast, nothing is known in non-mammalian vertebrates. We evaluated nitrite influence on cardiac performance in the perfused beating heart of three different cold-blooded vertebrates, i.e. two teleost fishes, the temperate red-blooded Anguilla anguilla, the Antarctic stenotherm, hemoglobinless Chionodraco hamatus (icefish), and the frog Rana esculenta. We showed that, under basal conditions, in all animals nitrite influences cardiac mechanical performance, inducing negative inotropism in eel and frog, while being a positive inotrope in C. hamatus. In all species, these responses parallel the inotropic effects of authentic NO. We also demonstrated that the nitrite-dependent inotropic effects are i) dependent from NO synthase (NOS) activity in fish; ii) sensitive to NO scavenging in frog; iii) cGMP/PKG-dependent in both eel and frog. Results suggest that nitrite is an integral physiological source of NO and acts as a signalling molecule in lower vertebrate hearts, exerting relevant inotropic actions through different species-specific mechanisms.

  2. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    PubMed

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

  3. PARTIAL LIFE-CYCLE TOXICITY AND BIOCONCENTRATION MODELLING OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the U.S., the global distribution and relative persistence of PFOS indicates a need ...

  4. Sex-chromosome differentiation and ‘sex races’ in the common frog (Rana temporaria)

    PubMed Central

    Rodrigues, Nicolas; Vuille, Yvan; Loman, Jon; Perrin, Nicolas

    2015-01-01

    Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of ‘sex races’ proposed in the 1930s, with our two populations assigned to the ‘differentiated’ and ‘semi-differentiated’ races, respectively. Our results support the suggestion that ‘sex races’ differ in the genetic versus epigenetic components of sex determination. Analysing populations from the ‘undifferentiated race’ with high-density genetic maps should help to further test this hypothesis. PMID:25833852

  5. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).

    PubMed

    Sanzo, Domenico; Hecnar, Stephen J

    2006-03-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.

  6. Residues of polybrominated diphenyl ethers in frogs (Rana limnocharis) from a contaminated site, South China: tissue distribution, biomagnification, and maternal transfer.

    PubMed

    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.

  7. Effects of chronic aluminum and copper exposure on growth and development of wood frog (Rana sylvatica) larvae.

    PubMed

    Peles, John D

    2013-09-15

    Wood frogs (Rana sylvatica) were exposed to aluminum (Al; 10, 100, 500, 1000, or 2000 μgL(-1)) or copper (Cu; 1, 10, 50, 100, 200 μgL(-1)) at a pH of 4.70 from the beginning of the larval period through the completion of metamorphosis (range=43-102 days). Observations on mortality, malformation, time to reach specific developmental stages, body mass at these stages, and metamorphic success were made throughout the larval developmental period. Only one case of malformation was observed and mortality was ≤ 10% at all concentrations except the highest Cu concentration where the rate was 33%. All larvae that survived the experiment successfully completed metamorphosis, but significant effects on growth and development occurred for both metals and these were most prominent for Cu. At the highest Al concentration (2000 μgL(-1)), body mass of larvae was significantly lower (reduced by 17% compared to the control) at 20 days post hatching (DPH) and the time to reach the hind-limb (HL), front-limb (FL), and tail resorption (TR) stages was significantly increased (9-10 days longer than the control). Body mass of larvae exposed to the three highest concentrations of Cu (50, 100, 200 μgL(-1)) was reduced by 30-34% at 20 DPH. Exposure to these concentrations also resulted in increased time to reach the HL, FL, and TR stages with larvae in the highest concentration taking 21-29 days longer to reach these stages. Larvae exposed to 10 μgL(-1) Cu also took longer to reach the FL and TR stages of development, and exposure to all Cu concentrations increased tail resorption time by more than two days compared to the control. Although the only observed effects of Al were for a concentration that is probably not ecologically relevant, results demonstrate that environmentally-realistic levels of Cu may have significant biological effects that could influence individual fitness and population-level processes.

  8. Effects of agricultural pesticides on the immune system of Rana pipiens and on its resistance to parasitic infection.

    PubMed

    Christin, Marie-Soleil; Gendron, Andrée D; Brousseau, Pauline; Ménard, Lucie; Marcogliese, David J; Cyr, Daniel; Ruby, Sylvia; Fournier, Michel

    2003-05-01

    In the past 30 years, many amphibian species have suffered population declines throughout the world. Mass mortality have been frequently reported, and in several instances, infectious diseases appear to be the cause of death. The role that contaminants could play in these die-offs through immunotoxic effects has been poorly investigated. In this study, juvenile leopard frogs (Rana pipiens) were exposed for 21 d to a mixture of six pesticides (atrazine, metribuzin, aldicarb, endosulfane, lindane, and dieldrin) and subsequently challenged with a parasitic nematode, Rhabdias ranae. Exposure to the mixture at environmentally realistic concentrations significantly reduced lymphocyte proliferation. Three weeks after the end of the exposure, lymphocyte proliferation had recovered and was stimulated in frogs challenged with parasites with the exception of those previously exposed to the highest concentration. No pesticide effects on phagocytosis and splenocyte numbers were detectable at the end of the exposure period, but these two parameters were diminished 21 d after the infection challenge in frogs previously exposed to the highest levels of pesticides. In these animals, the prevalence of lung infection by R. ranae also tended to be higher. These results suggest that agricultural pesticides can alter the immune response of frogs and affect their ability to deal with parasitic infection.

  9. Interrelationship between food availability, fat body, and ovarian cycles in the frog, Rana tigrina, with a discussion on the role of fat body in anuran reproduction.

    PubMed

    Girish, S; Saidapur, S K

    2000-04-01

    Long-term experiments were conducted to study the progression of vitellogenic cycles in Rana tigrina (an annual breeder) having different foraging backgrounds and held under conditions of weekly or daily food supply and in presence or absence of abdominal fat bodies. They were autopsied in June to assess fecundity. In nature an adult R. tigrina produces on an average 4,000 eggs/100 g body mass (b.m.) And spawns in June-July following monsoon rains. Weekly feeding from July to next breeding season, June resulted in a significant decrease in both fecundity (1700 eggs/100 g body b.m.) And mean size of eggs, compared to well-fed or wild-caught frogs. The abdominal fat bodies were barely seen in frogs fed weekly throughout, whereas in frogs fed weekly from July-December but daily from January onwards, the fat bodies became noticeable (1% of b.m.) And number and mean size of eggs increased significantly over those fed weekly throughout. Frogs captured in January possessed enlarged fat bodies (5% of b.m.), depicting a good foraging history. Maintenance of these frogs on a weekly feeding regimen led to an exhaustion of fat stores. They produced less number of eggs (2, 000/100 g b.m.) As compared to wild frogs but of normal size, whereas daily feeding slowed down a depletion of fat body mass and also significantly increased fecundity (3,000/100 g b.m.) Over the weekly fed individuals. Sham operation or fat body ablation in October or February had no significant effect on total fecundity per se (3,000-3,500 eggs/100 g b.m.) Compared to that of wild-caught frogs. However, eggs were significantly smaller due to fat body ablation despite daily feeding. The study shows that food abundance/fat bodies influence egg size and number in R. tigrina and that a direct or indirect functional relationship exists between fat body and ovarian cycles that are characteristically inverse to each other. J. Exp. Zool. 286:487-493, 2000.

  10. Diverse families of antimicrobial peptides isolated from skin secretions of three species of East Asian frogs, Babina daunchina, Babina adenopleura, and Rana omeimontis (Ranidae).

    PubMed

    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.

  11. Evaluation of the skin peptide defenses of the Oregon spotted frog Rana pretiosa against infection by the chytrid fungus Batrachochytrium dendrobatidis.

    PubMed

    Conlon, J Michael; Reinert, Laura K; Mechkarska, Milena; Prajeep, Manju; Meetani, Mohammed A; Coquet, Laurent; Jouenne, Thierry; Hayes, Marc P; Padgett-Flohr, Gretchen; Rollins-Smith, Louise A

    2013-06-01

    Population declines due to amphibian chytridiomycosis among selected species of ranid frogs from western North America have been severe, but there is evidence that the Oregon spotted frog, Rana pretiosa Baird and Girard, 1853, displays resistance to the disease. Norepinephrine-stimulated skin secretions were collected from a non-declining population of R. pretiosa that had been exposed to the causative agent Batrachochytrium dendrobatidis. Peptidomic analysis led to identification and isolation, in pure form, of a total of 18 host-defense peptides that were characterized structurally. Brevinin-1PRa, -1PRb, -1PRc, and -1PRd, esculentin-2PRa and -PRb, ranatuerin-2PRa, -2PRb, -2PRc, and -2PRe, temporin-PRb and -PRc were identified in an earlier study of skin secretions of frogs from a different population of R. pretiosa known to be declining. Ranatuerin-2PRf, -2PRg, -2PRh, temporin-PRd, -PRe, and -PRf were not identified in skin secretions from frogs from the declining population, whereas temporin-PRa and ranatuerin-2PRd, present in skin secretions from the declining population, were not detected in the current study. All purified peptides inhibited the growth of B. dendrobatidis zoospores. Peptides of the brevinin-1 and esculentin-2 families displayed the highest potency (minimum inhibitory concentration = 6.25-12.5 μM). The study provides support for the hypothesis that the multiplicity and diversity of the antimicrobial peptide repertoire in R. pretiosa and the high growth-inhibitory potency of certain peptides against B. dendrobatidis are important in conferring a measure of resistance to fatal chytridiomycosis.

  12. Effects of D-aspartate treatment on D-aspartate oxidase, superoxide dismutase, and caspase 3 activities in frog (Rana esculenta) tissues.

    PubMed

    Burrone, Lavinia; Di Giovanni, Marcello; Di Fiore, M Maddalena; Baccari, Gabriella Chieffi; Santillo, Alessandra

    2010-06-01

    Although D-aspartate (D-Asp) has been recognized to have a physiological role within different organs, high concentrations could elicit detrimental effects on those same organs. In this study, we examined the D-aspartate oxidase (D-AspO) activity and the expression of superoxide dismutase 1 (SOD1) and caspase 3 in different tissues of the frog Rana esculenta after chronic D-Asp treatment. Our in vivo experiments, consisting of intraperitoneal (ip) injections of D-Asp (2.0 micromol/g b.w.) in frogs for ten consecutive days, revealed that all examined tissues can take up and accumulate D-Asp. Further, in D-Asp treated frogs, i) the D-AspO activity significantly increased in all tissues (kidney, heart, testis, liver, and brain), ii) the SOD1 expression (antioxidant enzyme) significantly increased in the kidney, and iii) the caspase 3 level (indicative of apoptosis) increased in both brain and heart. Particularly, after the D-Asp treatment we found in both brain and heart (which showed the lowest SOD1 levels) a significant increase of the caspase 3 expression and, vice versa, in the kidney (which showed the highest SOD1 expression) a significant decrease of the caspase 3 expression. Therefore, we speculate that, in frog tissue, D-AspO plays an essential role in modulating the D-Asp concentration. In addition, exaggerated D-Asp concentrations activated SOD1 as cytoprotective mechanism in the kidney, whereas, in the brain and in the heart, where the antioxidant action of SOD1 is limited, caspase 3 was activated.

  13. Evidence for Directional Selection at a Novel Major Histocompatibility Class I Marker in Wild Common Frogs (Rana temporaria) Exposed to a Viral Pathogen (Ranavirus)

    PubMed Central

    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

  14. 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.

    PubMed

    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.

  15. An integrative study of the temperature dependence of whole animal and muscle performance during jumping and swimming in the frog Rana temporaria.

    PubMed

    Navas, C A; James, R S; Wakeling, J M; Kemp, K M; Johnston, I A

    1999-12-01

    The aims of this study were: (1) to analyze individual variation in frog locomotor performance, (2) to compare the thermal sensitivity of jumping and swimming, and (3) to contrast whole animal versus muscle fiber performance at different temperatures. The jumping and swimming performance of Rana temporaria was analyzed at 5, 10, 15 and 20 degrees C. Muscle fiber bundles were isolated from lateral gastrocnemius and subjected to the length and activation patterns thought to occur in vivo. As temperature increased, locomotor performance in R. temporaria improved with a Q10 of 1.2 for both jump take-off velocity and mean swimming velocity. The slope of the relationship between performance and temperature (TE) was similar for both locomotor parameters and was described by the equation z-scores of locomotor performance = 0.127 x TE - 1.585. Although some frogs performed better than others relative performance was affected by locomotor type and temperature. Locomotor performance improved with temperature as the power required during take-off and the mean muscle power output increased with Q10 values of 1.7 and 1.6 respectively. The mean muscle power output during take-off was only 34% of the calculated requirements for the whole animal, suggesting the involvement of elastic strain energy storage mechanisms.

  16. Observations of Interspecific amplexus between western North American ranid frogs and the introduced American bullfrog (Rana catesbeiana) and an hypothesis concerning breeding interference

    USGS Publications Warehouse

    Pearl, Christopher A.; Hayes, M.P.; Haycock, Russ; Engler, Joseph D.; Bowerman, Jay

    2005-01-01

    Introduced American bullfrogs (Rana catesbeiana) come in contact with native amphibians on four continents and are well established in lowlands of western North America. To date, research on the effects of introduced bullfrogs on native frogs has focused on competition and predation, and is based largely on larval interactions. We present observations of interspecific amplexus between bullfrogs and two native ranid frogs (R. aurora and R. pretiosa) from six sites across the Pacific Northwest that imply that this interaction is more widespread than currently recognized. Our observations indicate that R. catesbeiana juveniles and subadults in this region are of appropriate size to elicit marked amplectic responses from males of both native species. Our literature review suggests that greater opportunity may exist for pairings between R. catesbeiana and native R. aurora or R. pretiosa than among syntopic native ranids in western North America. We hypothesize that interspecific amplexus with introduced R. catesbeiana could result in reproductive interference with negative demographic consequences in native ranid populations that have been reduced or altered by other stressors.

  17. Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China.

    PubMed

    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 < 0.05). Additionally, the blood-brain barrier was found to work efficiently to suppress these compounds entering brain tissues in this species (liver/brain concentration ratio > 1, p < 0.05), and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog.

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

    NASA Astrophysics Data System (ADS)

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

    2001-03-01

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

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

    SciTech Connect

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

    1990-09-01

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

  20. Sequencing and analysis of the internal transcribed spacers (ITSs) and coding regions in the EcoR I fragment of the ribosomal DNA of the Japanese pond frog Rana nigromaculata.

    PubMed

    Sumida, Masayuki; Kato, Yoji; Kurabayashi, Atsushi

    2004-04-01

    The rDNA of eukaryotic organisms is transcribed as the 40S-45S rRNA precursor, and this precursor contains the following segments: 5' - ETS - 18S rRNA - ITS 1 - 5.8S rRNA - ITS 2 - 28S rRNA - 3'. In amphibians, the nucleotide sequences of the rRNA precursor have been completely determined in only two species of Xenopus. In the other amphibian species investigated so far, only the short nucleotide sequences of some rDNA fragments have been reported. We obtained a genomic clone containing the rDNA precursor from the Japanese pond frog Rana nigromaculata and analyzed its nucleotide sequence. The cloned genomic fragment was 4,806 bp long and included the 3'-terminus of 18S rRNA, ITS 1, 5.8S rRNA, ITS 2, and a long portion of 28S rRNA. A comparison of nucleotide sequences among Rana, the two species of Xenopus, and human revealed the following: (1) The 3'-terminus of 18S rRNA and the complete 5.8S rRNA were highly conserved among these four taxa. (2) The regions corresponding to the stem and loop of the secondary structure in 28S rRNA were conserved between Xenopus and Rana, but the rate of substitutions in the loop was higher than that in the stem. Many of the human loop regions had large insertions not seen in amphibians. (3) Two ITS regions had highly diverged sequences that made it difficult to compare the sequences not only between human and frogs, but also between Xenopus and Rana. (4) The short tracts in the ITS regions were strictly conserved between the two Xenopus species, and there was a corresponding sequence for Rana. Our data on the nucleotide sequence of the rRNA precursor from the Japanese pond frog Rana nigromaculata were used to examine the potential usefulness of the rRNA genes and ITS regions for evolutionary studies on frogs, because the rRNA precursor contains both highly conserved regions and rapidly evolving regions.

  1. Regeneration of lumbar dorsal root axons into the spinal cord of adult frogs (Rana pipiens), an HRP study.

    PubMed

    Liuzzi, F J; Lasek, R J

    1985-02-22

    Lumbar dorsal roots of adult frogs were crushed or cut and reanastomosed. Following survival times of up to 75 days, the regenerating dorsal roots were recut and anterogradely injury-filled with horseradish peroxidase. This revealed that in the adult frog, regenerating axons re-enter the spinal cord. Comparison of the distribution of these axons with that of normal dorsal root axons showed that there is a partial restoration of the segmental distribution in the gray matter. However, the long ascending sensory tract of the dorsal funiculus was not restored. The dorsal funiculus was markedly gliotic and had relatively few labelled, regenerated axons. The labelled axons that were seen in the dorsal funiculus either extended longitudinally for a distance just beneath the pia, apparently in association with the glia limitans, or traversed the region to enter the dorsal gray matter. Most of the large and small diameter axons that entered the gray matter did so by passing through the region of the dorsolateral fasciculus. Within the gray matter, small diameter, regenerated axons arborized in the region of the dorsal terminal field, a region that has been shown in the normal frog to receive cutaneous afferents only. Many large diameter axons, presumably muscle afferents, arborized in the ventral terminal field, a region shown in the normal frog to receive muscle afferents exclusively. However, many of these large diameter axons had arborizations that extended to both terminal fields, thus suggesting that some abberant connections are made during dorsal root regeneration in the adult frog.

  2. Big mountains but small barriers: Population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China

    PubMed Central

    Zhan, Aibin; Li, Cheng; Fu, Jinzhong

    2009-01-01

    Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Results Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may

  3. LEOPARD syndrome

    MedlinePlus

    LEOPARD syndrome is a very rare inherited disorder in which there are problems with the skin, face, ... LEOPARD syndrome is inherited as an autosomal dominant trait. This means the person only needs the abnormal ...

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

    PubMed Central

    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

  5. Immunoreactivities of IL-1β and IL-1R in oviduct of Chinese brown frog (Rana dybowskii) during pre-hibernation and the breeding period.

    PubMed

    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.

  6. Population and life-stage-specific effects of two herbicide formulations on the aquatic development of European common frogs (Rana temporaria).

    PubMed

    Wagner, Norman; Veith, Michael; Lötters, Stefan; Viertel, Bruno

    2017-01-01

    Environmental contamination is suggested to contribute to amphibian population declines. However, the effects of a contaminant on a particular amphibian species can differ among populations. The authors investigated the toxic effects of 2 herbicide formulations on different populations and on representative developmental stages of the European common frog (Rana temporaria). Larvae from forest populations were more sensitive to a commonly used glyphosate-based herbicide compared with individuals from agrarian land. Median lethal concentrations correlated with measured glyphosate levels in the breeding ponds, which may be a sign of evolved tolerances. The reverse result was observed for a less commonly used cycloxydim-based herbicide. Effects of the glyphosate-based herbicide were stronger for earlier larval stages compared with later larval stages. Hence, applications in early spring (when early larvae are present in breeding ponds) pose greater risk concerning acute toxic effects on R. temporaria. With regard to late larval stages, short exposure (96 h) of prometamorphic larvae prolonged time to metamorphosis, but only at the highest test concentration that did not significantly induce mortality. This could be due to impairment of the thyroid axis. Notably, nearly all test concentrations of the 2 herbicides provoked growth retardation. Further research on how evolved or induced tolerances are acquired, actual contamination levels of amphibian habitats, and potential endocrine effects of glyphosate-based herbicides is necessary. Environ Toxicol Chem 2017;36:190-200. © 2016 SETAC.

  7. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica)

    PubMed Central

    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

  8. Diseases of frogs and toads

    USGS Publications Warehouse

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

    2005-01-01

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

  9. Inbreeding and road effect zone in a Ranidae: the case of Agile frog, Rana dalmatina Bonaparte, 1840.

    PubMed

    Lesbarrères, David; Pagano, Alain; Lodé, Thierry

    2003-08-01

    Inbreeding has often been invoked in the extinction of local populations. In eleven western France populations of Agile frog studied, observed heterozygosity was significantly lower than expected in all cases, giving new evidence of such a depression in small populations. It especially occurred in ponds located near an highway rather than in undisturbed populations (FIS = 0.544 and 0.315, respectively). Thus, our results argue for a "road effect zone". Discussing about road distance and conservation policies, we propose that roads are directly involved in inbreeding and in local extinction. Thus, road construction ought to consider conservation management.

  10. Cloning and expression of genes enocoding antimicrobial peptides and bradykinin from the skin and brain of Oki Tago's brown frog, Rana tagoi okiensis.

    PubMed

    Tazato, Shoro; Conlon, J Michael; Iwamuro, Shawichi

    2010-08-01

    Previous studies led to the isolation from skin extracts of Oki Tago's brown frog, Rana tagoi okiensis of five antimicrobial peptides belonging to the brevinin-1 (brevinin-1TOa), temporin (temporin-TOa and -TOb), and ranatuerin-2 (ranatuerin-2TOa and -2TOb) families, and bradykinin (BK) identical to mammalian BK. Using the reverse-transcription polymerase chain reaction (RT-PCR), we have now cloned from skin total RNA preparations cDNAs encoding biosynthetic precursors of brevinin-1TOa and brevinin-1TOb (containing the substitution Gly(1)-->Val), temporin-TOa and -TOb, and ranatuerin-2TOa and -2TOb. In addition, three cDNA clones encoding preprobradykinins were obtained that contained either one, two, or three tandem repeats of the sequence of BK followed by the sequence of [Thr(6)]-BK. In tissue expression analyses, preprobrevinin-1, preprotemporin, and preproranatuerin-2 gene transcripts were detected at higher levels in brain compared with peripheral tissues (heart, small intestine, kidney, liver lung, skeletal muscle, stomach, and testis). RT-PCR of brain RNA resulted in the amplification of cDNAs encoding ranatuerin-2TOc and ranatuerin-2TOd that contained the amino acid substitutions Lys(6)-->Arg and Ala(14)-->Thr, respectively compared with ranatuerin-2TOb. cDNAs encoding preprobrevinin-1TOa and preprotemporin-TOa were amplified from brain RNA as well as a second preprotemporin cDNA that contained a 10-nucleotide insertion that introduced a frame shift resulting in a premature stop codon. A cDNA encoding a novel peptide, DK25 (DVNDLKNLCAKTHNLLPMCAMFGKK) was amplified from brain RNA but neither DK25 nor its putative post-translationally modified form, DF22-amide (DVNDLKNLCAKTHNLLPMCAMF.NH(2)) displayed antimicrobial or hemolytic activities.

  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)

    USGS Publications Warehouse

    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. The genetic contribution to sex determination and number of sex chromosomes vary among populations of common frogs (Rana temporaria).

    PubMed

    Rodrigues, N; Vuille, Y; Brelsford, A; Merilä, J; Perrin, N

    2016-07-01

    The patterns of sex determination and sex differentiation have been shown to differ among geographic populations of common frogs. Notably, the association between phenotypic sex and linkage group 2 (LG2) has been found to be perfect in a northern Swedish population, but weak and variable among families in a southern one. By analyzing these populations with markers from other linkage groups, we bring two new insights: (1) the variance in phenotypic sex not accounted for by LG2 in the southern population could not be assigned to genetic factors on other linkage groups, suggesting an epigenetic component to sex determination; (2) a second linkage group (LG7) was found to co-segregate with sex and LG2 in the northern population. Given the very short timeframe since post-glacial colonization (in the order of 1000 generations) and its seemingly localized distribution, this neo-sex chromosome system might be the youngest one described so far. It does not result from a fusion, but more likely from a reciprocal translocation between the original Y chromosome (LG2) and an autosome (LG7), causing their co-segregation during male meiosis. By generating a strict linkage between several important genes from the sex-determination cascade (Dmrt1, Amh and Amhr2), this neo-sex chromosome possibly contributes to the 'differentiated sex race' syndrome (strictly genetic sex determination and early gonadal development) that characterizes this northern population.

  13. Superimposed maps of the monocular visual fields in the caudolateral optic tectum in the frog, Rana pipiens.

    PubMed

    Winkowski, Daniel E; Gruberg, Edward R

    2005-01-01

    The superficial layers of the frog optic tectum receive a projection from the contralateral eye that forms a point-to-point map of the visual field. The monocular part of the visual field of the contralateral eye is represented in the caudolateral region of the tectum while the binocular part of the visual field is represented in the rostromedial tectum. Within the representation of the binocular field (rostromedial tectum), the maps of visual space from each eye are aligned. The tectal representation of the binocular visual field of the ipsilateral eye is mediated through a crossed projection from the midbrain nucleus isthmi. This isthmotectal projection also terminates in the caudolateral region of the optic tectum, yet there has been no indication that it forms a functional connection. By extracellular recording in intermediate layer 7 of the caudolateral tectum, we have discovered electrical activity driven by visual stimulation in the monocular visual field of the ipsilateral eye. The units driven from the ipsilateral eye burst upon initial presentation of the stimulus. At individual layer 7 recording sites in the caudolateral tectum, the multiunit receptive field evoked from the ipsilateral eye is located at the mirror image spatial location to the multiunit receptive field driven by the contralateral eye. Thus, as revealed electrophysiologically, there are superimposed topographic maps of the monocular visual fields in the caudolateral tectum. The ipsilateral eye monocular visual field representation can be abolished by electrolytic ablation of contralateral nucleus isthmi.

  14. [Influence of oxidative processes in mitochondria on contractility of the frog Rana temporaria heart muscle. Effects of cadmium].

    PubMed

    Shemarova, I V; Korotkov, S M; Nesterov, V P

    2011-01-01

    The inotropic Cd2+ action on frog heart is studied with taking into account its toxic effects upon mitochondria. Cd2+ at concentrations of 1, 10, and 20 microM is established to decrease dosedependently (21.3, 50.3, and 72.0%, respectively) the muscle contraction amplitude; this is explained by its competitive action on the potential-controlled Ca2(+)-channels of the L-type (Ca 1.2). In parallel experiments on isolated rat heart mitochondria (RHM) it was shown that Cd2+ at concentrations of 15 and 25 microM produces swelling of non-energized and energized mitochondria in isotonic (with KNO2 and NH4NO3) and hypoosmotic (with 25 mM CH3COOK) media. Study of oxidative processes in RHM by polarographic method has shown 20 microM Cd2+ to disturb activity of respiratory mitochondrial chain. The rate of endogenous respiration of isolated mitochondria in the medium with Cd2+ in the presence of malate and succinate was approximately 5 times lower than in control. In experimental preparations, addition into the medium of DNP-uncoupler of oxidation and phosphorylation did not cause an increase of the oxygen consumption rate. Thus, the obtained data indicate that a decrease in the cardiac muscle contractility caused by Cd2+ is due not only to its direct blocking action on Ca2(+)-channels, but also is mediated by toxic effect on rat heart mitochondria, which was manifested as an increase in ion permeability of the inner mitochondrial membrane (IMM), acceleration of the energy-dependent K+ transport into the matrix of mitochondria, and inhibition of their respiratory chain.

  15. Effects of cell volume changes on membrane ionic permeabilities and sodium transport in frog skin (Rana ridibunda).

    PubMed Central

    Costa, P M; Fernandes, P L; Ferreira, H G; Ferreira, K T; Giraldez, F

    1987-01-01

    1. Membrane potential and conductances and short-circuit current were continuously measured with microelectrodes and conventional electrophysiological techniques in a stripped preparation of frog skin epithelium. The effects of the removal of chloride or sodium ions and the concentration or dilution of the serosal (inner) bathing solution were studied. 2. Chloride- or sodium-free solutions produced a cell depolarization of about 30 mV in parallel with a fall in the short-circuit current. Mucosal and serosal membrane conductances both decreased and the sodium permeability of the mucosal barrier was calculated to fall to about one-half its value in standard Ringer solution. The observed decrease in the short-circuit current is probably related to the combined effect of the decrease in sodium permeability and the decrease in the driving force across the mucosal membrane. 3. The removal of chloride or sodium ions reduced the depolarization caused by serosal perfusion with high-potassium solutions (50 mM-KCl). The ratio of the change in cell membrane potential under short-circuit conditions to the change in the potassium equilibrium potential (delta Ec(s.c.)/delta EK), was 0.59 in standard Ringer solution and 0.26 and 0.24 after the removal of chloride or sodium respectively. The depolarizing effect of barium-containing solutions (2 mM-BaCl2) was also markedly reduced in chloride- or sodium-free solutions, suggesting a decrease of the potassium selectivity of the serosal membrane in these conditions. 4. Increasing the osmolality of the serosal bathing solution produced similar effects, i.e. cell depolarization, fall in the short-circuit current and membrane conductances and reduction of the depolarizing effect of high-potassium and barium solutions. On the contrary, dilution of the serosal bath produced the opposite effects, consistent with an increase in the serosal permeability to potassium. 5. The effects of chloride- or sodium-free solutions were reversed by the

  16. Prevalence of skeletal and eye malformations in frogs from north-central United States: estimations based on collections from randomly selected sites

    USGS Publications Warehouse

    Schoff, P.K.; Johnson, C.M.; Schotthoefer, A.M.; Murphy, J.E.; Lieske, C.; Cole, R.A.; Johnson, L.B.; Beasley, V.R.

    2003-01-01

    Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.

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

    USGS Publications Warehouse

    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

  18. ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS. 1) DOSE-DEPENDENT INDUCTION OF HINDLIMB MALFORMATIONS IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of environmental stressors have been hypothesized as responsible for seeming increases in limb malformations in several species of North American amphibians. The purpose of this study was to generate dose-response data suitable for assessing the potential role of solar u...

  19. Conservation in the Teaching Laboratory--Substitution of Xenopus for Rana.

    ERIC Educational Resources Information Center

    Bernhart, David M; And Others

    1991-01-01

    Reports on experimental comparisons between the leopard frog, currently captured for laboratory use, and the African clawed frog, raised specifically for research. Except for the increased longevity of isolated nerve axons in the clawed frog, no other significant differences were established. Recommends laboratory use of clawed frogs as…

  20. Potential for Loss of Breeding Habitat for Imperiled Mountain Yellow-legged Frog ( Rana muscosa) in High Sierra Nevada Mountain Water Bodies due to Reduced Snowpack: Interaction of Climate Change and an Introduced Predator

    NASA Astrophysics Data System (ADS)

    Lacan, I.; Matthews, K. R.

    2005-12-01

    Year to year variation in snowpack (20-200% average) and summer rain create large fluctuations in the volume of water in ponds and small lakes of the higher elevation (> 3000 m) Sierra Nevada. These water bodies are critical habitat for the imperiled mountain yellow-legged frog, Rana muscosa, which has decreased in abundance by 90% during the past century, due in part to the loss of suitable habitat and introduction of a fish predator (trout, Oncorhynchus spp.). Climate change is predicted to reduce the amount of snowpack, potentially impacting amphibian habitats throughout the Sierra Nevada by further reducing the lake and pond water levels and resulting in drying of small lakes during the summer. Mountain yellow-legged frogs are closely tied to water during all life stages, and are unique in having a three- to four-year tadpole phase. Thus, tadpole survival and future recruitment of adult frogs requires adequate water in lakes and ponds throughout the year, but larger lakes are populated with fish that prey on frogs and tadpoles. Thus, most successful frog breeding occurs in warm, shallow, fishless ponds that undergo wide fluctuations in volume. These water bodies would be most susceptible to the potential climate change effects of reduced snowpack, possibly resulting in lower tadpole survival. This study explores the link between the changes in water availability -- including complete pond drying -- and the abundance and recruitment of mountain yellow-legged frog in Dusy Basin, Kings Canyon National Park, California, USA. We propose using the low-snowpack years (1999, 2002, 2004) as comparative case studies to predict future effects of climate change on aquatic habitat availability and amphibian abundance and survival. To quantify the year to year variation and changes in water volume available to amphibians, we initiated GPS lake mapping in 2002 to quantify water volumes, water surface area, and shoreline length. We tracked these changes by repeated mapping of

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

    ERIC Educational Resources Information Center

    Brown, Herrick

    2004-01-01

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

  2. Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A

    USGS Publications Warehouse

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.; Kaiser, Hinrich; Casper, Gary S.; Bernstein, Neil P.

    2000-01-01

    Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of

  3. Balancing Selection at a Frog Antimicrobial Peptide Locus: Fluctuating Immune Effector Alleles?

    PubMed Central

    Blouin, Michael S.

    2008-01-01

    Balancing selection is common on many defense genes, but it has rarely been reported for immune effector proteins such as antimicrobial peptides (AMPs). We describe genetic diversity at a brevinin-1 AMP locus in three species of leopard frogs (Rana pipiens, Rana blairi, and Rana palustris). Several highly divergent allelic lineages are segregating at this locus. That this unusual pattern results from balancing selection is demonstrated by multiple lines of evidence, including a ratio of nonsynonymous/synonymous polymorphism significantly higher than 1, the ZnS test, incongruence between the number of segregating sites and haplotype diversity, and significant Tajima's D values. Our data are more consistent with a model of fluctuating selection in which alleles change frequencies over time than with a model of stable balancing selection such as overdominance. Evidence for fluctuating selection includes skewed allele frequencies, low levels of synonymous variation, nonneutral values of Tajima's D within allelic lineages, an inverse relationship between the frequency of an allelic lineage and its degree of polymorphism, and divergent allele frequencies among populations. AMP loci could be important sites of adaptive genetic diversity, with consequences for host–pathogen coevolution and the ability of species to resist disease epidemics. PMID:18799711

  4. The current voltage relationship of the delayed outward current in the heart of the frog (Rana esculenta) and the tortoise (Testudo germani).

    PubMed

    de Hemptinne, A

    1978-11-30

    Steady state and non steady state I-V relationships of the resting membrane and delayed rectifying membrane were analysed by applying trapezoid voltage clamp pulses on atrial fibres isolated from the frog and the tortoise. The fibres were disposed in a perfusion chamber for double sucrose gap. In both types of preparation, a component of delayed rectification current was identified which was activated following a comparable time course. The amplitude of the delayed rectification current, when expressed either as normalized to the calculated membrane capacity or to the initial background current, is significantly larger in the frog than in the tortoise. Full activation of the delayed rectifying system can be demonstrated in the tortoise, while in the frog this process is presumably complicated by simultaneous accumulation of K ions in the extracellular region. The difference in magnitude of the delayed outward current has no influence on the duration of action potential which is recorded over the sucrose gap.

  5. Number of mast cells in the harderian gland of the green frog, Rana esculenta: the annual cycle and its relation to environmental and hormonal factors.

    PubMed Central

    Chieffi Baccari, G; Minucci, S; Marmorino, C; Vitiello Izzo, I

    1991-01-01

    The Harderian gland of the green frog contains mast cells. Their number shows annual variations, being more numerous in the winter months. The increase of mast cell number (MCN) is matched by a marked degranulation. No sex differences are found throughout the year. Manipulations of the photoperiod and temperature, either in winter or in summer, suggest that only the latter is responsible for the annual variations. Exposure to higher temperatures causes a decrease in the MCN in the winter frogs, while exposure of the summer frogs to low temperatures provokes the opposite effect. The pituitary gland also influences MCN. Hypophysectomy causes a decrease of MCN, with a return to normal following replacement therapy with homologous pars distalis homogenate. Among pituitary hormones, only ACTH mimics the effect of pars distalis homogenate. However, a possible link seems to exist between environmental (temperature) and hormonal (pituitary) factors, since hypophysectomy prevents the increase of MCN in the summer frogs exposed to low temperatures. Images Fig. 2 PMID:1817144

  6. The contribution of ventricular apicobasal and transmural repolarization patterns to the development of the T wave body surface potentials in frogs (Rana temporaria) and pike (Esox lucius).

    PubMed

    Vaykshnorayte, Marina A; Azarov, Jan E; Tsvetkova, Alena S; Vityazev, Vladimir A; Ovechkin, Alexey O; Shmakov, Dmitry N

    2011-05-01

    The study aimed at the simultaneous determination of the transmural and apicobasal differences in the repolarization timing and the comparison of the contributions of these two repolarization gradients to the development of the body surface T wave potentials in animals with the single heart ventricle (fishes and amphibians). Unipolar potentials were measured on the body surface, epicardium and in the intramural (subepicardial, Epi; midmyocardial; and subendocardial, Endo) ventricular layers of 9 pike and 8 frogs. Activation times, repolarization times and activation-recovery intervals were determined. A transmural gradient in repolarization durations in frogs (Endo>Epi, P<0.024) corresponds to the gradient in repolarization times. No significant transmural difference in repolarization duration is observed in pike that produces a repolarization sequence from Endo to Epi (Endofrogs.

  7. Relationship between estradiol-17 beta seasonal profile and annual vitellogenin content of liver, fat body, plasma, and ovary in the frog (Rana esculenta).

    PubMed

    Varriale, B; Pierantoni, R; Di Matteo, L; Minucci, S; Milone, M; Chieffi, G

    1988-03-01

    The seasonal plasma estradiol-17 beta (E2-17 beta) profile and annual vitellogenin content of liver, fat body, plasma, and ovary were investigated in Rana esculenta. Concomitant with the increase in E2-17 beta, vitellogenin peaked in liver, plasma, and ovary during autumn and winter, while it remained at a relatively high concentration in fat body during spring. In vitro experiments showed that E2-17 beta (10(-9) M) is ineffective in inducing vitellogenin production in fat body, but is effective in inducing vitellogenin production in liver. As fat bodies do not produce the vitellogenin they contain, we suggest that fat bodies are involved in the transfer of vitellogenin to the ovary.

  8. Immunofluorescence studies on gonadotropin releasing hormone (GRH) in the fore-brain and the neurohypophysis of the green frog, Rana esculenta L.

    PubMed

    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.

  9. Premitotic DNA synthesis in the brain of the adult frog (Rana esculenta L. ): An autoradiographic sup 3 H-thymidine study

    SciTech Connect

    Bernocchi, G.; Scherini, E.; Giacometti, S.; Mares, V. )

    1990-12-01

    Replicative synthesis of DNA in the brain of the adult frog was studied by light microscope autoradiography. Animals collected during the active period (May-June) and in hibernation (January) were used. In active frogs, 3H-thymidine labelling occurred mainly in the ependymal cells which line the ventricles. The mean labelling index (LI%) was higher in the ependyma of the lateral and fourth ventricles than in the ependyma of the lateral diencephalon and tectal parts of the mesencephalon. In the recessus infundibularis and preopticus the number of labelled cells (LCs) was several times greater than in the lateral parts of the third ventricle. LCs were seen subependymally only occasionally. The incidence of LCs in the parenchyma of the brain was much lower in most regions than in the ventricular ependyma; LCs were mainly small and, from their nuclear morphology, they were glial cells. The LI% reached the highest value in the septum hippocampi and in the nucleus entopeduncularis. In these locations, LCs were larger and closer in size to the nerve cells of these regions. From comparison with data obtained earlier in the brain of mammals, it is evident that the distribution of proliferating cells in the olfactory and limbic system is phylogenetically conservative. The occurrence of pyknotic cells in the same areas which contain LCs, suggests that cell division reflects in part the process of cell renewal observed in mammals. However, proliferating cells could also be linked to the continuous growth observed in non-mammalian vertebrates. In hibernating frogs, LCs and pyknoses were not seen or were found occasionally, which further indicates the functional significance of both processes.

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

    EPA Science Inventory

    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...

  11. [Effect of the level of lighting on 14C-GABA efflux from the isolated retina of the frog Rana ridibunda].

    PubMed

    Arutiunian, Zh E; Gevorgian, G A; Petrosian, A M

    1981-01-01

    Studies have been made of the effect of changes in illumination levels on 14C + GABA efflux in the isolated retina of the frog R. ridibunda. When the retina loaded with 14C-GABA is stimulated by darkness, the efflux of radioactivity immediately increases. After reaching a peak, the efflux of 14C-GABA slightly decreases attaining steady level which is higher than the level of spontaneous efflux observed during weak (approximately 0.05 lux) illumination. This high level is preserved as long as the retina remains in darkness. During illumination of the retina (transition from darkness to 60 lux), two types of response are observed. In some cases, insignificant increase of GABA efflux from the retina is followed by its rapid decrease up to the level which is observed during weak illumination. In other cases, immediately after illumination the decrease in GABA efflux takes place (in 6 experiments out of 10). In accordance with the data of Voaden [6], it is suggested that 14C + GABA is liberated from horizontal and amacrine cells. The data obtained in the present investigation are discussed in terms of Trifonov [14] and Byzov [15] hypothesis. These data confirm the idea that GABA acts as a retinal neurotransmitter in the frog.

  12. Morphological correlates of aquatic and terrestrial locomotion in a semi-aquatic frog, Rana esculenta: no evidence for a design conflict

    PubMed Central

    Nauwelaerts, Sandra; Ramsay, Jason; Aerts, Peter

    2007-01-01

    Semi-aquatic frogs are faced with an unusual locomotory challenge. They have to swim and jump using the same apparatus, i.e. the hind limbs. Optimization of two tasks that require mutually incompatible morphologies or physiologies cannot occur simultaneously. In such cases, natural selection will result in some compromise, i.e. an intermediate phenotype that can perform both tasks reasonably well, but its performance will never match that of a specialized phenotype. We found no direct evidence for a trade-off between jumping and swimming performance nor for a coupled optimization. This could be due to the importance of overall quality, as suggested by the fact that some frogs possess greater overall muscularity than others, irrespective of their body size. Another explanation could be that some morphological characteristics have a positive effect on both locomotor modes and others show a trade-off effect. The net effect of these characteristics could result in an overall absence of correlation between the two locomotor performances. Size has a great influence on the morphological data and on jumping performance, but not if performance is expressed as velocity. The body shape of an anuran is conservative and scales mostly isometrically. PMID:17331179

  13. River islands, refugia and genetic structuring in the endemic brown frog Rana kukunoris (Anura, Ranidae) of the Qinghai-Tibetan Plateau.

    PubMed

    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.

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

    USGS Publications Warehouse

    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. Seasonal changes in the cytomorphology of hypophyseal ACTH cells in relation to the reproduction cycle of the female of the frog Rana tigerina (Daud.).

    PubMed

    Pramoda, S; Saidapur, S K

    1991-01-01

    The hypophyseal ACTH (basophil type 3 or B3), cells of R. tigerina display seasonal changes in cytomorphology (nuclear, cytoplasm and cell area), staining intensity and cytoplasmic granulation. The cytoplasmic granules are fine and stain blackish purple with McConaill's lead haematoxylin, with Herlant's AB and the PAS and OG techniques they stain brownish red. The tinctorial response of their cytoplasm is PAS- and OG-positive and AB-negative. The B3 cells are low columnar or cuboidal in form and are smaller than the gonadotrophs (B2 cells). Towards the rostral border of the pars distalis they are larger and are associated with blood vessels, whereas in the caudal region they are smaller. Seasonal changes in the granulation and degranulation of the ACTH cells are also more prominent in the rostral region of the pars distalis than in the caudal region. During April, May and June a marked increase occurs in ACTH cell size and the number of cytoplasmic secretory granules, concurrently with events like vitellogenesis, lipid depletion from the fat bodies and breeding activity. During the post-breeding regression phase (and especially from August to November), the B3 cells decrease markedly in size and become devoid of secretory granules; their recovery begins slowly from December onwards. The findings suggest that the secretory activity of the ACTH cells in the frog undergoes seasonal changes which possibly influence vitellogenesis, lipolysis of the fat bodies and breeding activity.

  16. Experimental alteration of the relationship between the external calcium concentration and the contractile force generated by auricular trabeculae isolated from the heart of the frog, Rana pipiens.

    PubMed

    Chapman, R A

    1971-10-01

    1. The contractile strength generated by isolated frog auricular trabeculae has been determined by perfusion with high-K Ringer over a range of [Ca](o).2. Experiments are described in which the cubic relationship between the contracture tension and [Ca](o) has been changed to a square or a linear relationship.3. These results have been interpreted by proposing that three Ca compounds, whose concentrations are proportional to [Ca](o), act co-operatively at some stage of the process leading to the generation of tension.4. The change in contractile strength, determined by regular electrically evoked twitches, has been investigated at different temperatures and the results have been explained by assuming that the concentrations of the three hypothetical activating compounds vary at different rates when [Ca](o) is altered.5. The staircase response is supposed to develop as the consequence of an increase in the concentrations of the two activating Ca compounds with the slowest time constants.6. The possible physical representations of the hypothetical activating compounds are discussed.

  17. [T-channels and Na+,Ca2+-exchangers as components of the Ca2+-system of the myocardial activity regulation of the frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2009-01-01

    Earlier we have shown that regulation of rhythm and strength of the frog heart contractions, mediated by transmitters of the autonomic nervous system, is of the Ca2+-character. In the present work, we studied chrono- and inotropic effect of verapamil--an inhibitor of Ca2+-channels of the L-type, of nickel chloride--an inhibitor of Ca2+-channels of the T-type, and of Na+,Ca2+-exchangers as well as of adrenaline and acetylcholine (ACh) after nickel chloride. It has been found that the intracardially administered NiCl2 at a dose of 0.01 microg/kg produced a sharp fall of amplitude of action potential (AP) and an almost twofold deceleration of heart rate (HR). The intracardiac administration of NiCl2 (0.01 microg/kg) on the background of action of verapamil (6 mg/kg, i/m) led as soon as after 3 min to even more prominent HR deceleration and to further fall of the AP amplitude by more than 50% as compared with norm. The intracardiac administration of adrenaline (0.5 mg/kg) partly restored the cardiac activity. However, preservation of the myocardium electrical activity in such animals was brief and its duration did not exceed several minutes. Administration of Ni2+ on the background of acetylcholine (3.6 mg/kg) led to almost complete cessation of cardiac activity. As soon as after 3 min after injection of this agent the HR decreased to 2 contractions/min. On EG, the 10-fold fall of the AP amplitude was recorded. The elucidate role of extra- and intracellular Ca2+ in regulation of heart contractions, isometric contraction of myocardium preparations was studied in response to action of NiCl2 (10-200 microM), verapamil (70 microM), adrenaline (5 microM), and acetylcholine (0.2 microM) after NiCl2. It is found that Ni2+ caused a dose-dependent increase of the muscle contraction amplitude. Minimal change of the contraction amplitude (on average, by 14.9% as compared with control) was recorded at a Ni2+ concentration of 100 microM. An increase of Ni2+ in the sample to 200

  18. Patch Clamp on the Luminal Membrane of Exocrine Gland Acini from Frog Skin (Rana esculenta) Reveals the Presence of Cystic Fibrosis Transmembrane Conductance Regulator–like Cl− Channels Activated by Cyclic AMP

    PubMed Central

    Sørensen, Jakob Balslev; Larsen, Erik Hviid

    1998-01-01

    Chloride channels in the luminal membrane of exocrine gland acini from frog skin (Rana esculenta) constituted a single homogeneous population. In cell-attached patches, channels activated upon exposure to isoproterenol, forskolin, or dibutyryl-cAMP and isobutyl-1-methyl-xanthine rectified in the outward direction with a conductance of 10.0 ± 0.4 pS for outgoing currents. Channels in stimulated cells reversed at 0 mV applied potential, whereas channels in unstimulated cells reversed at depolarized potentials (28.1 ± 6.7 mV), indicating that Cl− was above electrochemical equilibrium in unstimulated, but not in stimulated, cells. In excised inside-out patches with 25 mM Cl− on the inside, activity of small (8-pS) linear Cl−-selective channels was dependent upon bath ATP (1.5 mM) and increased upon exposure to cAMP-dependent protein kinase. The channels displayed a single substate, located just below 2/3 of the full channel amplitude. Halide selectivity was identified as PBr > PI > PCl from the Goldman equation; however, the conductance sequence when either halide was permeating the channel was GCl > GBr >> GI. In inside-out patches, the channels were blocked reversibly by 5-nitro-2-(3-phenylpropylamino)benzoic acid, glibenclamide, and diphenylamine-2-carboxylic acid, whereas 4,4-diisothiocyanatostilbene-2,2-disulfonic acid blocked channel activity completely and irreversibly. Single-channel kinetics revealed one open state (mean lifetime = 158 ± 72 ms) and two closed states (lifetimes: 12 ± 4 and 224 ± 31 ms, respectively). Power density spectra had a double-Lorentzian form with corner frequencies 0.85 ± 0.11 and 27.9 ± 2.9 Hz, respectively. These channels are considered homologous to the cystic fibrosis transmembrane conductance regulator Cl− channel, which has been localized to the submucosal skin glands in Xenopus by immunohistochemistry (Engelhardt, J.F., S.S. Smith, E. Allen, J.R. Yankaskas, D.C. Dawson, and J.M. Wilson. 1994. Am. J. Physiol. 267

  19. Physiological responses of freeze-tolerant and -intolerant frogs: clues to evolution of anuran freeze tolerance.

    PubMed

    Costanzo, J P; Lee, R E; Lortz, P H

    1993-10-01

    Freeze tolerance in the wood frog, Rana sylvatica, is promoted by multiple, integrated physiological responses to ice forming within body tissues. By analyzing the freezing responses of the sympatric, but freeze intolerant, leopard frog (R. pipiens), we sought clues to the evolution of anuran freeze tolerance. Physiological responses critical to R. sylvatica's freeze tolerance, such as the synthesis and distribution of the cryoprotectant glucose, protective dehydration of organs, and deferred cardiac failure, were present, but comparatively less pronounced, in R. pipiens. Both species were innately tolerant of hyperglycemia. Glucose supplements did not enhance the freezing viability of R. pipiens, although in vitro tests of cryoprotectant efficacy revealed that glucose and glycerol provided comparable protection to erythrocytes of both species. We conclude that the evolution of freeze tolerance in R. sylvatica is not only promoted by its desiccation tolerance and the fortuitous biophysical consequences of freezing (e.g., exothermic induction of cardioacceleration and moderation of cooling rate) but also involves a progressive enhancement of fundamental physiological stress responses.

  20. 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. (R825867)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. Unmasking Rana okinavana Boettger, 1895 from the Ryukyus, Japan (Amphibia: Anura: Ranidae).

    PubMed

    Matsui, Masafumi

    2007-02-01

    Examination of the lectotype and a paralectotype of Rana okinavana Boettger, 1895 revealed that the species is not a brown frog of the subgenus Rana, occurring in the middle group of the Ryukyu Archipelago, but is identical with a frog of the subgenus Nidirana from the southern group of the Archipelago and Taiwan, now called R. psaltes Kuramoto, 1985. The type locality of R. okinavana given in the original description, Okinawa of the middle Ryukyus, is highly doubtful and should be somewhere in the Yaeyama Islands of the southern Ryukyus. The name R. psaltes is relegated to a subjective junior synonym of R. okinavana Boettger, 1895, while the brown frog of the subgenus Rana from the northern Ryukyus requires a replacement name.

  2. The weak link: do muscle properties determine locomotor performance in frogs?

    PubMed Central

    Roberts, Thomas J.; Abbott, Emily M.; Azizi, Emanuel

    2011-01-01

    Muscles power movement, yet the conceptual link between muscle performance and locomotor performance is poorly developed. Frog jumping provides an ideal system to probe the relationship between muscle capacity and locomotor performance, because a jump is a single discrete event and mechanical power output is a critical determinant of jump distance. We tested the hypothesis that interspecific variation in jump performance could be explained by variability in available muscle power. We used force plate ergometry to measure power produced during jumping in Cuban tree frogs (Osteopilus septentrionalis), leopard frogs (Rana pipiens) and cane toads (Bufo marinus). We also measured peak isotonic power output in isolated plantaris muscles for each species. As expected, jump performance varied widely. Osteopilus septentrionalis developed peak power outputs of 1047.0 ± 119.7 W kg−1 hindlimb muscle mass, about five times that of B. marinus (198.5 ± 54.5 W kg−1). Values for R. pipiens were intermediate (543.9 ± 96.2 W kg−1). These differences in jump power were not matched by differences in available muscle power, which were 312.7 ± 28.9, 321.8 ± 48.5 and 262.8 ± 23.2 W kg−1 muscle mass for O. septentrionalis, R. pipiens and B. marinus, respectively. The lack of correlation between available muscle power and jump power suggests that non-muscular mechanisms (e.g. elastic energy storage) can obscure the link between muscle mechanical performance and locomotor performance. PMID:21502120

  3. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow... the Federally threatened California red-legged frog (Rana draytonii), under the Endangered Species Act... California red-legged frog on the property subject to the Agreement (Enrolled Property), which is owned...

  4. LEOPARD on a personal computer

    SciTech Connect

    Lancaster, D.B.

    1988-01-01

    The LEOPARD code is very widely used to produce four- or two-group cross sections for water reactors. Although it is heavily used it had not been downloaded to the PC. This paper has been written to announce the completion of downloading LEOPARD. LEOPARD can now be run on anything from the early PC to the most advanced 80386 machines. The only requirements are 512 Kbytes of memory (LEOPARD actually only needs 235, but with buffers, 256 Kbytes may not be enough) and two disk rives (preferably, one is a hard drive). The run times for various machines and configurations are summarized. The accuracy of the PC-LEOPARD results are documented.

  5. A fatal leopard attack.

    PubMed

    Hejna, Petr

    2010-05-01

    A rare case of a big cat fatal attack is presented. A male leopard that had escaped from its unlocked cage attacked a 26-year-old male zoo worker. The man sustained penetrating injuries to the neck with consequent external bleeding. The man died while being transported to the hospital as a result of the injuries sustained. The wounds discovered on the victim's body corresponded with the known methods of leopard attacks and with findings on the carcasses of animals killed by leopards in the wild. The conclusion of the medicolegal investigation was that the underlying cause of death was a bite wound to the neck which lacerated the left internal jugular vein, the two main branches of the left external carotid artery, and the cervical spine. The cause of death was massive external bleeding. Special attention is paid to the general pattern of injuries sustained from big cat attacks.

  6. Mitotic activity in dorsal epidermis of Rana pipiens.

    NASA Technical Reports Server (NTRS)

    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.

  7. Toxicity of the conventional energetics TNT and RDX relative to new insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    PubMed

    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.

  8. Only skin deep: shared genetic response to the deadly chytrid fungus in susceptible frog species.

    PubMed

    Rosenblum, Erica Bree; Poorten, Thomas J; Settles, Matthew; Murdoch, Gordon K

    2012-07-01

    Amphibian populations around the world are threatened by an emerging infectious pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Bd). How can a fungal skin infection kill such a broad range of amphibian hosts? And do different host species have a similar response to Bd infection? Here, we use a genomics approach to understand the genetic response of multiple susceptible frog species to Bd infection. We characterize the transcriptomes of two closely related endangered frog species (Rana muscosa and Rana sierrae) and analyse whole genome expression profiles from frogs in controlled Bd infection experiments. We integrate the Rana results with a comparable data set from a more distantly related susceptible species (Silurana tropicalis). We demonstrate that Bd-infected frogs show massive disruption of skin function and show no evidence of a robust immune response. The genetic response to infection is shared across the focal susceptible species, suggesting a common effect of Bd on susceptible frogs.

  9. Bioaccumulation kinetics of the conventional energetics TNT and RDX relative to insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    PubMed

    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.

  10. Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2009-01-15

    Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

  11. Myofiber turnover is used to retrofit frog jaw muscles during metamorphosis.

    PubMed

    Alley, K E

    1989-01-01

    Metamorphic reorganization of the head in anuran amphibians entails abrupt restructuring of the jaw complex as larval feeding structures are transformed into their adult configurations. In this morphometric study, light microscopy wa used to analyze the larval maturation and metamorphic transfiguration of the adductor jaw muscles in the leopard frog (Rana pipiens). Larval jaw muscles, first established during embryogenesis, continue to grow by fiber addition until prometamorphosis, stage XII. Thereafter, fiber number remains stable but additional muscle growth continues by hypertrophy of the individual fibers until metamorphic climax. During metamorphic stages XIX-XXIII, a complete involution of all larval myofibers occurs. Simultaneously, within the same muscle beds, a second wave of myogenesis produces myoblasts which are the precursors of adult jaw myofibers. New muscle fibers continue to be added to these muscles well after the completion of metamorphosis; however, the total duration of the postmetamorphic myogenic period has not been defined. These observations provide clear evidence that the entir population of primary myofibers used in larval oral activity disappears from the adductor muscle beds and is replaced by a second wave of myogenesis commencing during climax. These findings indicate that the adductor jaw muscles are prepared for adult feeding by a complicated cellular process that retrofits existing muscle beds with a completely new complement of myofibers.

  12. Climatic oscillations triggered post-Messinian speciation of Western Palearctic brown frogs (Amphibia, Ranidae).

    PubMed

    Veith, M; Kosuch, J; Vences, M

    2003-02-01

    Oscillating glacial cycles over the past 2.4 million years are proposed to have had a major impact on the diversity of contemporary species communities. We used mitochondrial and nuclear DNA sequence data to infer phylogenetic relationships within Western Palearctic brown frogs and to test the influence of Pliocene and Pleistocene climatic changes on their evolution. We sequenced 1976bp of the mitochondrial genes 16S rRNA and cytochrome b and of the nuclear rhodopsin gene for all current species and subspecies. Based on an established allozyme clock for Western Palearctic water frogs and substitution rate constancy among water frogs and brown frogs, we calibrated a molecular clock for 1425bp of the 16S and rhodopsin genes. We applied this clock to date speciation events among brown frogs. Western Palearctic brown frogs underwent a basal post-Messinian radiation about 4 million years ago (mya) into five major clades: three monotypic lineages (Rana dalmatina, Rana latastei, Rana graeca), an Anatolian lineage, and a lineage comprising Rana italica, Rana arvalis, and all Iberian taxa. Polytypic lineages radiated further in concordance with the onset of climatic oscillations ca. 3.2, 2.0, and 1.0-0.6 mya, respectively. The dated fossil record corroborates our paleobiogeographic scenario. We conclude that drastic climatic changes followed by successive temperature oscillations "trapped" most brown frog species in their southern European glacial refugia with enough time to speciate. Substantial dispersal was only possible during extensive interglacial periods of a constant subtropical climate.

  13. Tyzzer's disease in snow leopards.

    PubMed

    Schmidt, R E; Eisenbrandt, D L; Hubbard, G B

    1984-01-01

    Tyzzer's disease was diagnosed histologically in 2 litters of newborn snow leopard kittens. The gross and histological lesions were similar to those reported in domestic cats and other animals. No signs of illness was noted in either of the snow leopard dams.

  14. An early post-traumatic reaction of lymph-heart striated muscle fibers in adult frog Rana temporaria during the first postoperative week: An electron microscopic and autoradiographic study.

    PubMed

    Krylova, Marina I; Bogolyubov, Dmitry S

    2015-12-01

    According to the current opinion, lymph-heart striated muscle represents a specialized type of skeletal muscles in frogs. Here, we studied muscle fibers in mechanically damaged lymph hearts during the first postoperative week using electron-microscopic autoradiography. We present evidence that both, the satellite cells and pre-existing muscle fibers bordering the site of injury, contribute directly to the lymph-heart muscle regeneration. Several muscle fibers located in the vicinity of the damaged area displayed features of nuclear and sarcoplasmic activation. We also observed ultrastructural changes indicating activation of a few satellite cells, namely decondensation of chromatin, enlargement of nuclei and nucleoli, appearance of free ribosomes and rough endoplasmic reticulum tubules in the cytoplasm. Electron-microscopic autoradiography showed that 4 h after single (3)H-thymidine administration on the seventh day after injury not only the activated satellite cells, but also some nuclei of myofibers bordering the injured zone are labeled. We showed that both, the myonuclei of fibers displaying the signs of degenerative/reparative processes in the sarcoplasm and the myonuclei of the fibers enriched with highly organized myofibrils, can re-enter into the S-phase. Our results indicate that the nuclei of lymph-heart myofibers can reactivate DNA synthesis during regenerative myogenesis, unlike the situation in regenerating frog skeletal muscle where myogenic cells do not synthesize DNA at the onset of myofibrillogenesis.

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

    EPA Science Inventory

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

  16. Pesticides and Population Declines of California Alpine Frogs

    EPA Science Inventory

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

  17. Periodontal status in snow leopards.

    PubMed

    Cook, R A; Stoller, N H

    1986-11-01

    Periodontal examinations were performed on ten 1- to 22-year-old snow leopards (6 males and 4 females), using dentistry methods for determining the plaque and gingival indices. All tooth surfaces were probed, and alveolar bone attachment loss was determined. After subgingival plaque removal, plaque specimens were examined for differential bacterial morphotypes. The small number of leopards evaluated precluded definitive statistical analysis. However, the progression from gingival health to gingivitis to periodontitis was similar to that seen in man. Therefore, the use of plaque index, gingival index, alveolar bone attachment loss, and differential bacterial morphotypes can be used to determine the dental health of snow leopards.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

  20. Inhibitory vs. protective effects of N-acetyl-l-cysteine (NAC) on the electromechanical properties of the spontaneously beating atria of the frog (Rana ridibunda): an ex vivo study.

    PubMed

    Papaefthimiou, Chrisovalantis; Antonopoulou, Efthimia; Theophilidis, George

    2009-03-01

    The results of this study have shown that N-acetyl-l-cysteine (NAC), a compound used for protection of tissues or cell cultures against the deleterious effects of various environmental pollutants, has certain unusual effects on the contraction of the spontaneously beating atria of the frog isolated in saline (ex vivo): (1) NAC, 6.0 and 10.0mM, eliminated, in a concentration-dependent manner, the contractile properties of the atria (force and frequency) within minutes, without affecting its electrical properties; (2) the IC(50) of NAC for the force was 5.09+/-1.01 mM (n=6) [4.98-5.19 mM, 95% confidence interval (CI)], significantly lower than the IC(50) for the frequency, 6.15+/-1.01 mM, (6.02-6.29 mM, 95% CI), indicating that working atria cells are more sensitive to NAC than autorhythmic cells. The no-observed-effect concentration (NOEC) was 1-2mM; (3) the pattern of NAC-induced inhibition of electromechanical activity was similar to that of verapamil, an indication that NAC possibly affects L-type voltage-gated calcium channels; (4) NAC at 2mM protected against cadmium-induced inhibition of atria contraction. The IC(50) for cadmium was 17.9+/-1.1 microM (n=6) (16.9-19.0 microM, 95% CI), while in the presence of 2mM NAC, it became 123.3+/-1.0 microM (n=6) (114.8-132.4 microM, 95% CI). The same concentration of NAC failed to exert any protective effects against rotenone (5 microM)-induced inhibition of atria contraction. The protective effects of NAC are probably due to chelation of cadmium, rather than scavenging of oxidants.

  1. Effects of adenosine perfusion on the metabolism and contractile activity of Rana ridibunda heart.

    PubMed

    Lazou, A; Beis, I

    1987-01-01

    The effects of adenosine were examined on the isolated perfused heart of the frog Rana ridibunda. Adenosine produced negative chronotropic and inotropic effects on frog ventricle in a concentration-dependent manner. The effects of adenosine on cardiac metabolism were also investigated by measuring the tissue content of adenine nucleotides, lactate, pyruvate, adenosine and inorganic phosphate, during adenosine perfusion. Adenosine had no effect on the tissue content of metabolites. No net synthesis of adenine nucleotides was observed during perfusion with increasing concentrations of adenosine. Lactate output from the heart decreased significantly with adenosine perfusion. Correlation of adenosine effects on cardiac muscle with the effects of hypoxia are discussed.

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

    PubMed

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

    2016-04-15

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

  3. Limb malformations and abnormal sex hormone concentrations in frogs.

    PubMed Central

    Sower, S A; Reed, K L; Babbitt, K J

    2000-01-01

    Declines in amphibian populations, and amphibians with gross malformations, have prompted concern regarding the biological status of many anuran species. A survey of bullfrogs, Rana catesbeiana, and green frogs, Rana clamitans, conducted in central and southern New Hampshire showed malformed frogs at 81% of the sites sampled (13 of 16 sites). Brain gonadotropin-releasing hormone (GnRH) and the synthesis of androgens and estradiol, hormones essential to reproductive processes, were measured from limb-malformed and normal (no limb malformation) frogs. Normal frogs had significantly higher concentrations (nearly 3-fold) of in vitro produced androgens and of brain GnRH than malformed frogs. Because most malformations are thought to occur during development, we propose that environmental factors or endocrine-disrupting chemicals that may cause developmental abnormalities also act during early development to ultimately cause abnormally reduced GnRH and androgen production in adult frogs. The consequences of reduced GnRH and androgens on anuran reproductive behavior and population dynamics are unknown but certainly may be profound and warrant further research. PMID:11102301

  4. Evolutionary avenues for, and constraints on, the transmission of frog lung flukes (Haematoloechus spp.) in dragonfly second intermediate hosts.

    PubMed

    Bolek, Matthew G; Janovy, John

    2007-06-01

    Metacercariae survival patterns and their distribution in second intermediate odonate hosts were examined for 4 species of frog lung flukes. Surveys of aquatic larvae and recently emerged teneral dragonflies and damselflies indicated that prevalence and mean abundance of Haematoloechus spp. metacercariae were significantly lower in teneral dragonflies than larval dragonflies, while there was no significant difference in prevalence or mean abundance of Haematoloechus spp. metacercariae among larval and teneral damselflies. Experimental infections of dragonflies indicated that metacercariae of Haematoloechus coloradensis and Haematoloechus complexus were located in the head, thorax, and branchial basket of dragonflies, whereas metacercariae of Haematoloechus longiplexus and Haematoloechus parviplexus were restricted to the branchial basket of these hosts. Metacercariae of H. coloradensis, H. complexus, and H. longiplexus infected the head, thorax, and abdomen of damselflies, but these insects were resistant to infection with H. parviplexus. Subsequent metamorphosis experiments on experimentally infected dragonflies indicated that most metacercariae of H. longiplexus were lost from the branchial basket during metamorphosis, but most metacercariae of H. coloradensis, H. complexus, and H. parviplexus survived dragonfly metamorphosis. These observations suggest that the observed ecological host specificity of H. longiplexus in semiterrestrial leopard frogs may be due to few metacercariae of H. longiplexus reaching these frogs in a terrestrial environment. Because of the uncertain validity of Haematoloechus varioplexus as a distinct species from its synonym H. parviplexus, their morphological characters were reevaluated. The morphological data on H. varioplexus and H. parviplexus indicate that they differ in their acetabulum length and width, ovary shape, testes length, and egg length and width. Experimental infections of plains leopard frogs, northern leopard frogs, and

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

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

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

    PubMed

    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.

  7. RANA CATESBEIANA (AMERICAN BULLFROG) DIET

    EPA Science Inventory

    RANA CATESBELANA (American Bullfrog). DIET. Data were obtained opportunistically
    from 28 adult (M = 14; F = 14) bullftogs collected in April 2001 from the Meadow Valley Wash
    located between the cities of Carp and Elgin, Lincoln County, Nevada, USA (N37'17':WI14'30'). Alth...

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

    USGS Publications Warehouse

    Mazerolle, M.J.

    2005-01-01

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

  9. FROGS report

    NASA Astrophysics Data System (ADS)

    FROGS Reports present information on current research relevant to felsic magmatism, including commentaries on problems of current interest. Please contact Calvin Miller, Geology, 6028B, Vanderbilt University, Nashville, TN 37235; tel. 615-322-2986 about your own research, conferences, and ideas for stimulating commentaries.

  10. Fantastic Frogs!

    ERIC Educational Resources Information Center

    Scott, Kym

    2002-01-01

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

  11. Eleutherodactylus frog introductions to Hawaii

    USGS Publications Warehouse

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

    1999-01-01

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

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

    PubMed

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

    2010-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

  14. Wood frog adaptations to overwintering in Alaska: new limits to freezing tolerance.

    PubMed

    Larson, Don J; Middle, Luke; Vu, Henry; Zhang, Wenhui; Serianni, Anthony S; Duman, John; Barnes, Brian M

    2014-06-15

    We investigated the ecological physiology and behavior of free-living wood frogs [Lithobates (Rana) sylvaticus] overwintering in Interior Alaska by tracking animals into natural hibernacula, recording microclimate, and determining frog survival in spring. We measured cryoprotectant (glucose) concentrations and identified the presence of antifreeze glycolipids in tissues from subsamples of naturally freezing frogs. We also recorded the behavior of wood frogs preparing to freeze in artificial hibernacula, and tissue glucose concentrations in captive wood frogs frozen in the laboratory to -2.5°C. Wood frogs in natural hibernacula remained frozen for 193 ± 11 consecutive days and experienced average (October-May) temperatures of -6.3°C and average minimum temperatures of -14.6 ± 2.8°C (range -8.9 to -18.1°C) with 100% survival (N=18). Mean glucose concentrations were 13-fold higher in muscle, 10-fold higher in heart and 3.3-fold higher in liver in naturally freezing compared with laboratory frozen frogs. Antifreeze glycolipid was present in extracts from muscle and internal organs, but not skin, of frozen frogs. Wood frogs in Interior Alaska survive freezing to extreme limits and durations compared with those described in animals collected in southern Canada or the Midwestern United States. We hypothesize that this enhancement of freeze tolerance in Alaskan wood frogs is due to higher cryoprotectant levels that are produced by repeated freezing and thawing cycles experienced under natural conditions during early autumn.

  15. Evolution of serum albumin intron-1 is shaped by a 5′ truncated non-long terminal repeat retrotransposon in western Palearctic water frogs (Neobatrachia)

    PubMed Central

    Plötner, Jörg; Köhler, Frank; Uzzell, Thomas; Beerli, Peter; Schreiber, Robert; Guex, Gaston-Denis; Hotz, Hansjürg

    2009-01-01

    A 5′ truncated non-LTR CR1-like retrotransposon, named RanaCR1, was identified in the serum albumin intron-1 (SAI-1) of at least seven species of western Palearctic water frogs (WPWF). Based on sequence similarity of the carboxy-terminal region (CTR) of ORF2 and the highly conserved 3′ untranslated region (3′ UTR), RanaCR1-like elements occur also in the genome of Xenopus tropicalis and Rana temporaria. Unlike other CR1 elements, RanaCR1 contains a CA microsatellite in its 3′ UTR. The low nucleotide diversity of the 3′ UTR compared to the CTR and to SAI-1 suggests that this region still plays a role in WPWF, either as a structure-stabilizing element, or within a species-specific transcriptional network. Length variation of water frog SAI-1 sequences is caused by deletions that extend in some cases beyond the 5′ or 3′ ends of RanaCR1, probably a result of selection for structural and functional stability of the primary transcript. The impact of RanaCR1 on SAI-1 evolution is also indicated by the significant negative correlation between the length of both SAI-1 and RanaCR1 and the percentage GC content of RanaCR1. Both SAI-1 and RanaCR1 sequences support the sister group relationship of R. perezi and R. saharica, which are placed in the phylogenetic tree at a basal position, the sister clade to other water frog taxa. It also supports the monophyly of the R. lessonae group; of Anatolian water frogs (R. cf. bedriagae), which are not conspecific with R. bedriagae; and of the European ridibunda group. Within the ridibunda clade, Greek frogs are clearly separated, supporting the hypothesis that Balkan water frogs represent a distinct species. Frogs from Atyrau (Kazakhstan), the type locality of R. ridibunda, were heterozygous for a ridibunda and a cf. bedriagae specific allele. PMID:19665056

  16. Spatial Patterns of Airborne Pesticides in the Alpine Habitat of a Declining California Amphibian, The Mountain Yellow-Legged Frog

    EPA Science Inventory

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

  17. Spatial Patterns of Airborne Pesticides in the Alpine Habitat of a Declining Calfornia Amphibian, The Mountain Yellow-Legged Frog

    EPA Science Inventory

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

  18. Airborne Pesticides as an Unlikely Cause for Population Declines of Alpine Frogs in the Sierra Nevada, California

    EPA Science Inventory

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

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

    PubMed

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

    2012-05-21

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

  20. Do you know this syndrome? Leopard syndrome*

    PubMed Central

    Cançado, Flávio Heleno da Silva Queiroz; da Silva, Luis Candido Pinto; Taitson, Paulo Franco; de Andrade, Ana Carolina Dias Viana; Pithon, Matheus Melo; Oliveira, Dauro Douglas

    2017-01-01

    Hypertrophic cardiomyopathy is known as Leopard syndrome, which is a mnemonic rule for multiple lentigines (L), electrocardiographic conduction abnormalities (E), ocular hypertelorism (O), pulmonary stenosis (P), abnormalities of genitalia (A), retardation of growth (R), and deafness (D). We report the case of a 12-year-old patient with some of the abovementioned characteristics: hypertelorism, macroglossia, lentigines, hypospadias, cryptorchidism, subaortic stenosis, growth retardation, and hearing impairment. Due to this set of symptoms, we diagnosed Leopard syndrome. PMID:28225973

  1. Hyperspectral analysis of columbia spotted frog habitat

    USGS Publications Warehouse

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

    2010-01-01

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

  2. [Ploidy and genetic structure of hybrid populations of water frogs Pelophylax esculentus (L., 1758) complex (Amphibia, Ranidae) of Ukraine].

    PubMed

    Mezhzherin, S V; Morozov-Leonov, S Iu; Rostovskaia, O V; Shabanov, D A; Sobolenko, L Iu

    2010-01-01

    The present study of green frog hybrid populations of Ukraine, including analysis of allozyme variability and planimetric analysis oferythrocytes size has confirmed that the unique region in this area is the Severski Donets basin The allopolyploid individuals there are met very frequently (5.7% of all investigated frogs). In other areas of Ukraine only two polyploid hybrids have been recorded. Beside that, one frog was defined as triploid Rana ridibundus. According to our investigations, all triploid hybrids from the Severski Donets basin are identified as P. esculentu (=lessonae)--2 ridibundus males.

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

    USGS Publications Warehouse

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

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and

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

    PubMed

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

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1,500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing

  5. Oxidative phosphorylation efficiency, proton conductance and reactive oxygen species production of liver mitochondria correlates with body mass in frogs.

    PubMed

    Roussel, Damien; Salin, Karine; Dumet, Adeline; Romestaing, Caroline; Rey, Benjamin; Voituron, Yann

    2015-10-01

    Body size is a central biological parameter affecting most biological processes (especially energetics) and the mitochondrion is a key organelle controlling metabolism and is also the cell's main source of chemical energy. However, the link between body size and mitochondrial function is still unclear, especially in ectotherms. In this study, we investigated several parameters of mitochondrial bioenergetics in the liver of three closely related species of frog (the common frog Rana temporaria, the marsh frog Pelophylax ridibundus and the bull frog Lithobates catesbeiana). These particular species were chosen because of their differences in adult body mass. We found that mitochondrial coupling efficiency was markedly increased with animal size, which led to a higher ATP production (+70%) in the larger frogs (L. catesbeiana) compared with the smaller frogs (R. temporaria). This was essentially driven by a strong negative dependence of mitochondrial proton conductance on body mass. Liver mitochondria from the larger frogs (L. catesbeiana) displayed 50% of the proton conductance of mitochondria from the smaller frogs (R. temporaria). Contrary to our prediction, the low mitochondrial proton conductance measured in L. catesbeiana was not associated with higher reactive oxygen species production. Instead, liver mitochondria from the larger individuals produced significantly lower levels of radical oxygen species than those from the smaller frogs. Collectively, the data show that key bioenergetics parameters of mitochondria (proton leak, ATP production efficiency and radical oxygen species production) are correlated with body mass in frogs. This research expands our understanding of the relationship between mitochondrial function and the evolution of allometric scaling in ectotherms.

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

    PubMed

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

    2015-01-15

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

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

    SciTech Connect

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

    1989-01-01

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

  8. Drainage ditches facilitate frog movements in a hostile landscape

    USGS Publications Warehouse

    Mazerolle, M.J.

    2005-01-01

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

  9. [Optical mapping of chronotopography of excitation of the frog heart ventricle epicardial surface in sinus rhythm].

    PubMed

    abramochkin, D V; Rozenshtraukh, L V

    2008-04-01

    Two points of early activation were shown on the surface of the frog Rana temporaria ventricle using optical mapping technique. These points are located on the left and right ventricular surface at equal distance from apex and base of the ventricle. The excitation approaches to epicardial ventricular surface at these points, and then it spreads all over the surface. Such pattern of epicardial activation is also shown in mammals where it is related to conduction system functioning. Thus, the precursor of conduction system seems to exist in the frog ventricle, too.

  10. Frog eat frog: exploring variables influencing anurophagy

    PubMed Central

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

    2015-01-01

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

  11. Role of Tibetan Buddhist monasteries in snow leopard conservation.

    PubMed

    Li, Juan; Wang, Dajun; Yin, Hang; Zhaxi, Duojie; Jiagong, Zhala; Schaller, George B; Mishra, Charudutt; McCarthy, Thomas M; Wang, Hao; Wu, Lan; Xiao, Lingyun; Basang, Lamao; Zhang, Yuguang; Zhou, Yunyun; Lu, Zhi

    2014-02-01

    The snow leopard (Panthera uncia) inhabits the rugged mountains in 12 countries of Central Asia, including the Tibetan Plateau. Due to poaching, decreased abundance of prey, and habitat degradation, it was listed as endangered by the International Union for Conservation of Nature in 1972. Current conservation strategies, including nature reserves and incentive programs, have limited capacities to protect snow leopards. We investigated the role of Tibetan Buddhist monasteries in snow leopard conservation in the Sanjiangyuan region in China's Qinghai Province on the Tibetan Plateau. From 2009 to 2011, we systematically surveyed snow leopards in the Sanjiangyuan region. We used the MaxEnt model to determine the relation of their presence to environmental variables (e.g., elevation, ruggedness) and to predict snow leopard distribution. Model results showed 89,602 km(2) of snow leopard habitat in the Sanjiangyuan region, of which 7674 km(2) lay within Sanjiangyuan Nature Reserve's core zones. We analyzed the spatial relation between snow leopard habitat and Buddhist monasteries and found that 46% of monasteries were located in snow leopard habitat and 90% were within 5 km of snow leopard habitat. The 336 monasteries in the Sanjiangyuan region could protect more snow leopard habitat (8342 km(2) ) through social norms and active patrols than the nature reserve's core zones. We conducted 144 household interviews to identify local herders' attitudes and behavior toward snow leopards and other wildlife. Most local herders claimed that they did not kill wildlife, and 42% said they did not kill wildlife because it was a sin in Buddhism. Our results indicate monasteries play an important role in snow leopard conservation. Monastery-based snow leopard conservation could be extended to other Tibetan Buddhist regions that in total would encompass about 80% of the global range of snow leopards.

  12. TEMPORAL AND SPATIAL PATTERNS OF AIRBORNE PESTICIDES IN THE ALPINE ENVIRONMENT OF A DECLINING CALIFORNIA AMPHIBIAN, THE MOUNTAIN YELLOW-LEGGED FROG

    EPA Science Inventory

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

  13. The role of gamont entry into erythrocytes in the specificity of Hepatozoon species (Apicomplexa: Adeleida) for their frog hosts.

    PubMed

    Dickson, Cory M; Ogbuah, Christopher T; Smith, Todd G

    2013-12-01

    Hepatozoon species are apicomplexan parasites that infect blood cells and viscera of terrestrial vertebrates. One species, Hepatozoon clamatae, primarily infects green frogs, Rana clamitans , whereas another, Hepatozoon catesbianae, primarily infects bullfrogs, Rana catesbeiana , although both species of parasite are capable of infecting either species of frog. The aim of this study was to determine whether the basis for this partial host specificity is manifested at the gamont, or intraerythrocytic, stage of the parasite's life cycle. Blood was drawn from infected frogs and treated in vitro with a saline solution to induce intracellular gamonts to emerge from host erythrocytes. This treated blood was added to in vitro samples of uninfected blood of green frogs and bullfrogs. After 1 hr, samples were analyzed to determine the level of re-entry of the parasites into uninfected erythrocytes. Results obtained using multiple combinations of donor and recipient frogs indicate that extracellular gamonts of both parasite species do not exhibit preference for erythrocytes of 1 frog species over those of another. These results suggest that the basis for the observed host specificity is not determined at the gamont stage and is more likely dependent on another stage in the parasite life cycle.

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

    PubMed Central

    Nakagawa, Hideki; Nishida, Yuuya

    2012-01-01

    Summary 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, P<0.05). A similar mechanism of velocity control has been known in head movements of the owl and in human saccades. By analogy, this suggests that the frog planned its escape velocity in advance of executing the turn, to make the duration of the escape behavior relatively constant. For escape turns less than 60°, the positive correlation was very strong (r2 = 0.7097, P<0.05). Thus, the frog controlled the angular velocity of small escape turns very accurately and completed the behavior within a constant time. On the other hand, for escape turns greater than 60°, the same correlation was not significant (r2 = 0.065, P>0.05). 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. PMID:23213389

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

    PubMed

    Nakagawa, Hideki; Nishida, Yuuya

    2012-11-15

    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 (r(2) = 0.5741, P<0.05). A similar mechanism of velocity control has been known in head movements of the owl and in human saccades. By analogy, this suggests that the frog planned its escape velocity in advance of executing the turn, to make the duration of the escape behavior relatively constant. For escape turns less than 60°, the positive correlation was very strong (r(2) = 0.7097, P<0.05). Thus, the frog controlled the angular velocity of small escape turns very accurately and completed the behavior within a constant time. On the other hand, for escape turns greater than 60°, the same correlation was not significant (r(2) = 0.065, P>0.05). 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 (r(2) = 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 (r(2) = 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.

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

    PubMed

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

    2013-11-01

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

  17. Gonadal abnormalities in frogs (Lithobates spp.) collected from managed wetlands in an agricultural region of Nebraska, USA

    USGS Publications Warehouse

    Papoulias, Diana M.; Schwarz, Matt S.; Mena, Lourdes

    2013-01-01

    Nebraska's Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration of exposures were unknown and due to an incomplete understanding of L. blairi sexual development. Emphasis is on describing the complex developmental biology of closely-related leopard frogs, how this understanding can explain RWB L. blairi anomalies, and the need for sampling at the appropriate life stage.

  18. Gonadal abnormalities in frogs (Lithobates spp.) collected from managed wetlands in an agricultural region of Nebraska, USA.

    PubMed

    Papoulias, Diana M; Schwarz, Matt S; Mena, Lourdes

    2013-01-01

    Nebraska's Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration of exposures were unknown and due to an incomplete understanding of L. blairi sexual development. Emphasis is on describing the complex developmental biology of closely-related leopard frogs, how this understanding can explain RWB L. blairi anomalies, and the need for sampling at the appropriate life stage.

  19. Overwintered Bullfrog tadpoles negatively affect Salamanders and Anurans in native amphibian communities

    USGS Publications Warehouse

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

    2004-01-01

    We examined the interactive effects of overwintered Bullfrog (Rana catesbeiana) tadpoles and pond hydroperiod on a community of larval amphibians in outdoor mesocosms including American Toads (Bufo americanus), Southern Leopard Frogs (Rana sphenocephala), and Spotted Salamanders (Ambystoma maculatum) - species within the native range of Bullfrogs. Spotted Salamanders and Southern Leopard Frogs were negatively influenced by the presence of overwintered Bullfrogs. Spotted Salamanders had shorter larval periods and slightly smaller masses at metamorphosis, and Southern Leopard Frogs had smaller masses at metamorphosis when reared with Bullfrogs than without. Presence of overwintered Bullfrogs, however, did not significantly affect American Toads. Longer pond hydroperiods resulted in greater survival, greater size at metamorphosis, longer larval periods, and later time until emergence of the first metamorphs for Southern Leopard Frog tadpoles and Spotted Salamander larvae. Our study demonstrated that overwintered Bullfrog tadpoles can respond to changing pond hydroperiods and can negatively impact metamorphosis of native amphibians.

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

    PubMed

    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.

  1. Rana computatrix to human language: towards a computational neuroethology of language evolution.

    PubMed

    Arbib, Michael A

    2003-10-15

    Walter's Machina speculatrix inspired the name Rana computatrix for a family of models of visuomotor coordination in the frog, which contributed to the development of computational neuroethology. We offer here an 'evolutionary' perspective on models in the same tradition for rat, monkey and human. For rat, we show how the frog-like taxon affordance model provides a basis for the spatial navigation mechanisms that involve the hippocampus and other brain regions. For monkey, we recall two models of neural mechanisms for visuomotor coordination. The first, for saccades, shows how interactions between the parietal and frontal cortex augment superior colliculus seen as the homologue of frog tectum. The second, for grasping, continues the theme of parieto-frontal interactions, linking parietal affordances to motor schemas in premotor cortex. It further emphasizes the mirror system for grasping, in which neurons are active both when the monkey executes a specific grasp and when it observes a similar grasp executed by others. The model of human-brain mechanisms is based on the mirror-system hypothesis of the evolution of the language-ready brain, which sees the human Broca's area as an evolved extension of the mirror system for grasping.

  2. Molecular cloning of natriuretic peptide receptor A from bullfrog (Rana catesbeiana) brain and its functional expression.

    PubMed

    Sekiguchi, T; Miyamoto, K; Mizutani, T; Yamada, K; Yazawa, T; Yoshino, M; Minegishi, T; Takei, Y; Kangawa, K; Minamino, N; Saito, Y; Kojima, M

    2001-08-08

    A comparative study of natriuretic peptide receptor (NPR) was performed by cloning the NPR-A receptor subtype from the bullfrog (Rana catesbeiana) brain and analyzing its functional expression. Like other mammalian NPR-A receptors, the bullfrog NPR-A receptor consists of an extracellular ligand binding domain, a hydrophobic transmembrane domain, a kinase-like domain and a guanylate cyclase domain. Sequence comparison among the bullfrog and mammalian receptors revealed a relatively low ( approximately 45%) similarity in the extracellular domain compared to a very high similarity ( approximately 92%) in the cytoplasmic regulatory and catalytic domains. Expression of NPR-A mRNA was detected in various bullfrog tissues including the brain, heart, lung, kidney and liver; highest levels were observed in lung. Functional expression of the receptor in COS-7 cells revealed that frog atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) elicited cyclic guanosine 3'5'-monophosphate production by stimulating the receptor in a dose-dependent manner from 10(-10) M concentrations. Rat ANP was also effective in stimulating the frog receptor whereas rat BNP and porcine BNP were less responsive to the receptor. On the other hand, frog C-type natriuretic peptide (CNP) as well as porcine CNP stimulated the receptor only at high concentrations (10(-7) M). This clearly indicates that the bullfrog receptor is a counterpart of mammalian NPR-A, and is specific for ANP or BNP but not for CNP.

  3. Status of the Leopard Laser Project in Nevada Terawatt Facility

    NASA Astrophysics Data System (ADS)

    Wiewior, Piotr P.; Astanovitskiy, A.; Aubry, G.; Batie, S.; Caron, J.; Chalyy, O.; Cowan, T.; Haefner, C.; Le Galloudec, B.; Le Galloudec, N.; Macaulay, D.; Nalajala, V.; Pettee, G.; Samek, S.; Stepanenko, Y.; Vesco, J.

    2009-06-01

    Nevada Terawatt Facility (NTF) currently operates a high-intensity laser system—Leopard. NTF already operates a powerful z-pinch device, called Zebra, for plasma and High Energy Density physics research. The unique research opportunities arise from the combination of NTF's terawatt Zebra z-pinch with 50-terawatt-class Leopard laser. This combination also provides opportunities to address fundamental physics of inertial fusion and high energy density physics with intense laser beam. We report on the status, design and architecture of the Leopard laser project. A first experiments carried out with Leopard will be also briefly mentioned.

  4. Distortion product otoacoustic emissions provide clues to hearing mechanisms in the frog

    NASA Astrophysics Data System (ADS)

    Vassilakis, Pantelis; Narins, Peter M.

    2003-10-01

    Cubic distortion product otoacoustic emissions (DPOAEs) were recorded from 10 Rana pipiens and 10 Rana catesbeiana, 5 males and 5 females each. The I/O curves obtained from the amphibian papilla (AP) of both species are very similar to the respective mammalian curves, indicating that, like in the mammalian cochlea, there may be an amplification process active in the frog AP. The DPOAE level dependence on primary levels is also similar to the mammalian case, suggesting a mechanical structure in the frog inner ear may be functioning analogously to the mammalian basilar membrane. DPOAE audiograms were obtained for primary frequencies spanning the animals hearing range and levels determined by the previous experiments. R. catesbeiana produce stronger emissions than R. pipiens and, consistent with previously reported sexual dimorphism in the mammalian and anuran auditory systems, females from both species produce stronger emissions than males. Additionally, the 2f1-f2 DPOAE is generated primarily at the DPOAE frequency place, while the 2f2-f1 DPOAE is generated primarily at a frequency place between the primaries. This difference in mammalian and frog DPOAEs may be linked to an anatomical difference that results in the acoustic energy following opposite paths through the mammalian and frog inner ears. [Work supported by NIH Grant No. DC-00222 to Peter M. Narins.] a)Currently at De Paul Univ., School of Music, Chicago, IL 60614.

  5. 76 FR 61895 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ...We, the U.S. Fish and Wildlife Service, announce a 12-month finding on a petition to list the northern leopard frog (Lithobates (=Rana) pipiens) under the Endangered Species Act of 1973, as amended (Act). After review of the best scientific and commercial information, we find that listing the northern leopard frog is not warranted at this time. However, we ask the public to submit to us any......

  6. Schrodinger Leopards in Bose-Einstein Condensates

    NASA Astrophysics Data System (ADS)

    Carr, Lincoln D.; Dounas-Frazer, Dimitri R.

    2008-03-01

    We present the complex quantum dynamics of vortices in Bose-Einstein condensates in a double well via exact diagonalization of a discretized Hamiltonian. When the barrier is high, vortices evolve into macroscopic superposition (NOON) states of a vortex in either well -- a Schrodinger cat with spots. Such Schrodinger leopard states are more robust than previously proposed NOON states, which only use two single particle modes of the double well potential.

  7. [Comparative sensitivity of liver monoamine oxidases of frog and whitefish to some tricyclic compounds].

    PubMed

    Basova, I N; Iagodina, O V

    2011-01-01

    There is performed a comparative analysis of action of four acridine derivatives and of one xanthene derivative (pyronine G) on activity of liver monoamine oxidase (MAO) of two species of poikilothermal freshwater animals: a representative of amphibians--the common frog Rana temnporaria and a representative of the order Salmonidae--the European whitefish Coregonus lavaretus. The studied synthetic hexamerous tricyclic compounds show the irreversible character of inhibition of intermediate potency towards the enzyme from both biological sources. There are obtained qualitative and quantitative differences in the reactional ability and selectivity of action of the studied inhibitors for liver MAO of frog and whitefish. The obtained data of the inhibitory analysis with use of specific substrates are an indirect proof for the existence in liver of the studies frog species of two molecular forms, whereas in the whitefish liver--single molecular MAO form.

  8. Molecular characterization of the leopard gecko POMC gene and expressional change in the testis by acclimation to low temperature and with a short photoperiod.

    PubMed

    Endo, Daisuke; Park, Min Kyun

    2004-08-01

    The gene for proopiomelanocortin (POMC), a common precursor of malanotropins, corticotropin, and beta-endorphin, was isolated and analyzed in the squamata species, the leopard gecko, Eublepharis macularius. Leopard gecko POMC (lgPOMC) cDNA is composed of 1299bp, excluding the poly(A) tail, and encodes 270 amino acids. The deduced amino acid sequence showed the same structural organization as that of other species and displayed identity with those of other vertebrates: 68% with mud turtles, 57/57% with African clawed frog A/B, 53% with chickens, and 45% with mice. In a phylogenic tree, the lgPOMC clustered with the sequences of the mud turtle POMC and python POMC. The lgPOMC gene comprises three exons and two introns and this structure is consistent with humans, rats, mice, African clawed frog and zebrafish. RT-PCR analysis revealed that the lgPOMC mRNA was expressed only in the whole brain, pituitary, and gonads. To analyze in more detail, a competitive assay system to quantify the expression levels of POMC mRNA was established. We measured the POMC mRNA expression levels in the leopard gecko testes following transfer from a condition of 29 degrees C, 16L/8D to 18 degrees C, 10L/14D over 6 weeks. This 6-week acclimation increased the POMC mRNA expression levels significantly. This suggests that the leopard gecko POMC-derived peptides play a role in the mediation of the effect of environmental factors on reproduction.

  9. A spotlight on snow leopard conservation in China.

    PubMed

    Alexander, Justine S; Zhang, Chengcheng; Shi, Kun; Riordan, Philip

    2016-07-01

    China holds the greatest proportion of the snow leopard's (Panthera uncia) global range and is central to their conservation. The country is also undergoing unprecedented economic growth, which increases both the threats to the snow leopard and the opportunities for its conservation. In this paper we aim to review published literature (from 1950 to 2014) in English and Mandarin on snow leopard ecology and conservation in China in order to identify thematic and geographic research gaps and propose research priorities. We first retrieved all published items that considered snow leopards in China (n = 106). We extracted from these papers 274 reports of snow leopard presence in China. We then reviewed a subset of papers (n = 33) of this literature, which specifically focused on snow leopard ecology and conservation within China. We introduced a thematic framework that allows a structured and comprehensive assessment of findings. This framework recognizes 4 critical and interrelated topics underpinning snow leopard ecology and conservation: habitat (distribution and protected area coverage); prey (distribution and abundance, predator-prey relationships); human interactions (hunting and trade, livestock interactions and conflicts); and the underlying policy context. Significant gains in knowledge as well as research gaps and priorities are discussed with reference to our framework. The modest quantity and limited scope of published research on the snow leopard in China calls for a continued and intensified effort to inform and support national conservation policies.

  10. Chloride conductance and mitochondria-rich cell density in isolated skin of Rana catesbeiana acclimated to various environments.

    PubMed

    Claro de Toledo, Manuel; Malheiros Lopes Sanioto, Sonia

    2002-08-01

    The Cl- conductance in isolated skin of frogs (Rana catesbeiana) acclimated to 30 mM solutions of NaCl, Na2SO4, MgCl2 and distilled water (DW) was studied. Transepithelial potential difference (PDtrans), short-circuit current (ISC) and total conductance (Gt) were measured under conditions such that there was Cl- flux in the presence and absence of Na+ transport. The Cl- content of the mucosal solution was acutely replaced with SO42- or gluconate to evaluate the effect of removal of Cl- conductance on electrophysiological parameters. Mitochondria-rich cell density (DMRC) was also measured. Skins from frogs acclimated to NaCl and Na2SO4 showed the lowest and the highest D(MRC), respectively, but no difference could be found between the skins from frogs acclimated to DW and MgCl2 indicating that DMRC is not unconditionally dependent on environmental Cl- in this species. Frogs acclimated to NaCl showed marked differences when compared to the other groups: the highest Gt, probably represented by a higher paracellular conductance; the lowest transepithelial electrical potential difference which remained invariant after replacement of mucosal Cl- with SO42- or replacement of mucosal Cl- with gluconate and an inwardly oriented positive current in the absence of bilateral Na+.

  11. Yet More Frogs

    ERIC Educational Resources Information Center

    Shutler, Paul M. E.

    2011-01-01

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

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

    USGS Publications Warehouse

    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.

  13. Patterns of Cranial Development in Larval Rana macrocnemis: Chondrocranial Size and Shape Relationship With Pelophylax bedriagae (Anura: Ranidae).

    PubMed

    Yildirim, Elıf; Kaya, Uğur

    2016-06-01

    Notwithstanding the abundance of amphibians, there are few descriptions about ranid cranial development. Herein, larval chondrocranial development of Uludağ frog, Rana macrocnemis (Boulenger, 1885), is described on cleared and double-stained specimens. Descriptions are related with the ontogeny of the chondrocranium and osteogenesis of the cranial skeleton. The larval chondrocranial development of R. macrocnemis is compared to those of Rana and Pelophylax larvae (Pelophylax bedriagae, Rana pipiens, R. palustris, R. sphenocephala, R. catesbeiana, R. clamitans and R. sylvatica). In R. macrocnemis, the first bones to ossify are the parasphenoid and exoccipital (Stage 33), followed by the frontoparietal and prootic (stages 35 and 40, respectively). The major reconstruction of the chondrocranium begins at Stage 41. The ossification sequence of R. macrocnemis is distinguished from other ranids. Adult cranial osteology of R. macrocnemis is compared to that of P. bedriagae. Osteologically, R. macrocnemis is different from P. bedriagae by the shape and size of the vomer and number of teeth. Additionally, geometric morphometric methods are used to analyze chondrocranial size and shape changes of ranid larva of R. macrocnemis and P. bedriagae. Anat Rec, 299:711-721, 2016. © 2016 Wiley Periodicals, Inc.

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

    PubMed

    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.

  15. Yet more frogs

    NASA Astrophysics Data System (ADS)

    Shutler, Paul M. E.

    2011-06-01

    Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical case (unequal numbers of frogs) as an extension of the symmetrical case. The issue of whether frogs of a given colour should be allowed to move in either direction is discussed. While it is possible to restrict to the case of movement in a single direction, results for bi-directional movement can be obtained by making the correspondence between the algorithm and its diagrammatic representation more concrete. The Frog Problem then becomes a form of constrained shortest path problem around the diagram, and from this point of view optimality of the algorithm becomes much clearer.

  16. Helminth infracommunities of Rana vaillanti brocchi (Anura: Ranidae) in Los Tuxtlas, Veracruz, Mexico.

    PubMed

    Paredes-Calderón, Laura; León-Règagnon, Virginia; García-Prieto, Luis

    2004-08-01

    A total of 76 adult individuals of Rana vaillanti were collected in Laguna Escondida, Los Tuxtlas, Veracruz, Mexico, and their helminth infracommunity structure was determined. Among the 21 helminth taxa collected (10 digeneans, 8 nematodes, and 3 acanthocephalans), the digenean Langeronia macrocirra reached the highest prevalence (64.4%), mean abundance (6.6), and mean intensity (10.4), as well as the highest total number of individuals (499). Only 2 frogs were uninfected, the remainder harbored between 1 and 7 helminth species and 1-102 individuals; mean species richness and abundance were 3.49 +/- 0.22 and 16.1 +/- 16.3, respectively. Langeronia macrocirra dominated in 50.6% of the infracommunities, with relatively low Berger-Parker index values (0.56); for this reason, the evenness was high (0.70 +/- 0.31), and consequently, diversity values are the highest recorded to date in species of Rana. However, patterns of helminth infracommunity richness and diversity were similar to those previously observed in amphibians. This structure is attributed to the feeding habits (between 66.7 and 81% of helminth species parasitizing R. vaillanti enter using the food web dynamics) and low vagility (the remainder species infect by host penetration).

  17. Cranial muscle development in frogs with different developmental modes: direct development versus biphasic development.

    PubMed

    Ziermann, Janine M; Diogo, Rui

    2014-04-01

    Normal development in anurans includes a free swimming larva that goes through metamorphosis to develop into the adult frog. We have investigated cranial muscle development and adult cranial muscle morphology in three different anuran species. Xenopus laevis is obligate aquatic throughout lifetime, Rana(Lithobates) pipiens has an aquatic larvae and a terrestrial adult form, and Eleutherodactylus coqui has direct developing juveniles that hatch from eggs deposited on leaves (terrestrial). The adult morphology shows hardly any differences between the investigated species. Cranial muscle development of E. coqui shows many similarities and only few differences to the development of Rana (Lithobates) and Xenopus. The differences are missing muscles of the branchial arches (which disappear during metamorphosis of biphasic anurans) and a few heterochronic changes. The development of the mandibular arch (adductor mandibulae) and hyoid arch (depressor mandibulae) muscles is similar to that observed in Xenopus and Rana (Lithobates), although the first appearance of these muscles displays a midmetamorphic pattern in E. coqui. We show that the mix of characters observed in E. coqui indicates that the larval stage is not completely lost even without a free swimming larval stage. Cryptic metamorphosis is the process in which morphological changes in the larva/embryo take place that are not as obvious as in normal metamorphosing anurans with a clear biphasic lifestyle. During cryptic metamorphosis, a normal adult frog develops, indicating that the majority of developmental mechanisms towards the functional adult cranial muscles are preserved.

  18. Toxicity of tetrachlorvinphos to Rana temporaria L.

    PubMed

    Gromysz-Kałkowska, K; Szubartowska, E

    1993-06-01

    1. Changes in the erythrocyte system of frogs poisoned with tetrachlorwinfos depend on the sex of the animals and the dose of pesticide applied. They are a result of the pathomorphological changes due to translocation of fluids from the tissues to the circulation and swelling of the blood cells. 2. Changes in the leucocyte system of frogs are caused by several mechanisms: lytic action of the pesticide on the blood cell membrane, the stressogenic effect of the agent and enhanced activity of the reticuloendothelial system. 3. The appearance of typical changes due to stress, after even the lowest dose of tetrachlorwinfos, and low LD50 values indicate that this pesticide is highly toxic for frogs. 4. The relatively high susceptibility of frogs to intoxication with tetrachlorwinfos is probably the result of a high affinity of cholinesterase to this pesticide, because of the presence of the P = O bond in its molecule.

  19. Potassium currents in auditory hair cells of the frog basilar papilla.

    PubMed

    Smotherman, M S; Narins, P M

    1999-06-01

    The whole-cell patch-clamp technique was used to identify and characterize ionic currents in isolated hair cells of the leopard frog basilar papilla (BP). This end organ is responsible for encoding the upper limits of a frog's spectral sensitivity (1.25-2.0 kHz in the leopard frog). Isolated BP hair cells are the smallest hair cells in the frog auditory system, with spherical cell bodies typically less than 20 microm in diameter and exhibiting whole-cell capacitances of 4-7 pF. Hair cell zero-current resting potentials (Vz) varied around a mean of -65 mV. All hair cells possessed a non-inactivating, voltage-dependent calcium current (I(Ca)) that activates above a threshold of -55 mV. Similarly all hair cells possessed a rapidly activating, outward, calcium-dependent potassium current (I(K)(Ca)). Most hair cells also possessed a slowly activating, outward, voltage-dependent potassium current (I(K)), which is approximately 80% inactive at the hair cell Vz, and a fast-activating, inward-rectifying potassium current (I(K1)) which actively contributes to setting Vz. In a small subset of cells I(K) was replaced by a fast-inactivating, voltage-dependent potassium current (I(A)), which strongly resembled the A-current observed in hair cells of the frog sacculus and amphibian papilla. Most cells have very similar ionic currents, suggesting that the BP consists largely of one homogeneous population of hair cells. The kinetic properties of the ionic currents present (in particular the very slow I(K)) argue against electrical tuning, a specialized spectral filtering mechanism reported in the hair cells of birds, reptiles, and amphibians, as a contributor to frequency selectivity of this organ. Instead BP hair cells reflect a generalized strategy for the encoding of high-frequency auditory information in a primitive, mechanically tuned, terrestrial vertebrate auditory organ.

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

    PubMed Central

    Savage, Anna E.; Terrell, Kimberly A.; Gratwicke, Brian; Mattheus, Nichole M.; Augustine, Lauren; Fleischer, Robert C.

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1–15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29–55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations. PMID:27293759

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

    PubMed

    Savage, Anna E; Terrell, Kimberly A; Gratwicke, Brian; Mattheus, Nichole M; Augustine, Lauren; Fleischer, Robert C

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1-15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29-55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations.

  2. Experimental infections of Rana esculenta with Aeromonas hydrophila: a molecular mechanism for the control of the normal flora.

    PubMed

    Simmaco, M; Mangoni, M L; Boman, A; Barra, D; Boman, H G

    1998-10-01

    Frogs can be useful models for studying the mechanisms that may regulate their natural microbial flora. Their skin glands produce a secretion containing 20-30 different peptides, some antimicrobial some neurotrophic. As they often live in soil or silt that is rich in microbes, they can be expected to be able to prevent or eliminate infections in very short periods of time. The bacterium Aeromonas hydrophila is widely distributed in nature and is considered as part of the natural flora of frogs and many animals, including humans. From an alternative frog strain of A. hydrophila, Bo-3, we isolated a spontaneous and stable mutant (Bo-3N), resistant to nalidixic acid, here used to follow the host-microbe interactions in experimental infection of mouth and skin of Rana esculenta. The skin peptides had been previously isolated, sequenced and cloned. We showed that skin treatment with a glucocorticoid (GC) cream blocked de novo synthesis of these peptides and, simultaneously, prepropeptide mRNAs disappeared while IkappaBalpha was up-regulated. Experimental mouth infections with 20 million cells of A. hydrophila Bo-3N showed that a normal wild frog can eliminate the bacteria from the mouth within 15 min, while a frog pretreated with GC cream for 1 h could not reduce Bo-3N below 3500 colony-forming units (CFU)/5 microl 'saliva'. An in vitro comparison showed that frog blood or serum allowed bacteria to grow, while the skin secretion killed the bacteria within 10 min. Using different enzyme-linked immunosorbent assays (ELISAs) with rabbit anti-Bo-3 serum as a positive control, we were able to rule out immunoglobulin G (IgG) binding to A. hydrophila. An assay for immunoglobulin M (IgM) (or some other serum component) in frog serum showed binding to A. hydrophila only corresponding to a few per cent of the positive control. For skin infections we bathed the frogs for 10 min in an overnight culture of Bo-3N diluted to about 10(7) CFU/ml. Electrical stimulation after the bath

  3. Nitric oxide modulates the frog heart ventricle morphodynamics.

    PubMed

    Acierno, Raffaele; Gattuso, Alfonsina; Guerrieri, Antonio; Mannarino, Cinzia; Amelio, Daniela; Tota, Bruno

    2008-09-01

    The aim of this work was to investigate in the avascular heart of the frog Rana esculenta the influence of nitric oxide (NO) on ventricular systolic and diastolic functions by using a novel image analysis technique. The external volume variations of the whole ventricle were monitored during the heart cycle by video acquisition(visible light) and analysed by an appropriately developed software with a specific formula for irregular convex solids. The system, which measures the rate of volume changes and the ejection fraction, directly determined the volumetric behaviour of the working frog heart after stimulation or inhibition of NOS-NOcGMP pathway. End-diastolic volume (EDVext), end-systolic volume (ESVext), contraction and relaxation velocities (dV/dtsys and dV/dtdia, respectively), stroke volume (SV) and ejection fraction (EF), were measured before and after perfusion with NOS substrate (L-arginine), NO donor (SIN-1), cGMP analogue (8-Br-cGMP),NOS inhibitors (NG-monomethyl-L-arginine, L-NMMA; L-N(5)-(1-iminoethyl)-ornithine, L-NIO; 7-Nitroindazole,7-NI) and guanylyl cyclase inhibitor (ODQ). The results showed that NO reduces ventricular systolicfunction improving diastolic filling, while NOS inhibition increases contractility impairing ventricular filling capacity. The presence of activated eNOS (p-eNOS) was morphologically documented, further supporting that the mechanical activity of the ventricular pump in frog is influenced by a tonic release of NOS-generated NO.

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

    PubMed

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

    2013-01-01

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

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

    USGS Publications Warehouse

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

    2013-01-01

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

  6. Applicability of Age-Based Hunting Regulations for African Leopards

    PubMed Central

    Balme, Guy Andrew; Hunter, Luke; Braczkowski, Alex Richard

    2012-01-01

    In species in which juvenile survival depends strongly on male tenure, excessive trophy hunting can artificially elevate male turnover and increase infanticide, potentially to unsustainable levels. Simulation models show that the likelihood of safe harvests can be improved by restricting offtakes to males old enough to have reared their first cohort of offspring to independence; in the case of African leopards, males were ≥7 years old. Here, we explore the applicability of an age-based approach for regulating trophy hunting of leopards. We conducted a structured survey comprising photographs of known-age leopards to assess the ability of wildlife practitioners to sex and age leopards. We also evaluated the utility of four phenotypic traits for use by trophy hunters to age male leopards in the field. Our logistic regression models showed that male leopard age affected the likelihood of survey respondents identifying the correct sex; notably, males <2 years were typically misidentified as females, while mature males (≥4 years) were sexed correctly. Mature male leopards were also more likely to be aged correctly, as were portrait photographs. Aging proficiency was also influenced by the profession of respondents, with hunters recording the lowest scores. A discriminant model including dewlap size, the condition of the ears, and the extent of facial scarring accurately discriminated among male leopard age classes. Model classification rates were considerably higher than the respective scores attained by survey respondents, implying that the aging ability of hunters could theoretically improve with appropriate training. Dewlap size was a particularly reliable indicator of males ≥7 years and a review of online trophy galleries suggested its wider utility as an aging criterion. Our study demonstrated that an age-based hunting approach is practically applicable for leopards. However, implementation would require major reform within the regulatory framework and the

  7. Glycogen synthase kinase-3: cryoprotection and glycogen metabolism in the freeze-tolerant wood frog.

    PubMed

    Dieni, Christopher A; Bouffard, Melanie C; Storey, Kenneth B

    2012-02-01

    The terrestrial anuran Rana sylvatica tolerates extended periods of whole-body freezing during the winter. Freezing survival is facilitated by extensive glycogen hydrolysis and distribution of high concentrations of the cryoprotectant glucose into blood and all tissues. As glycogenesis is both an energy-expensive process and counter-productive to maintaining sustained high cryoprotectant levels, we proposed that glycogen synthase kinase-3 (GSK-3) would be activated when wood frogs froze and would phosphorylate its downstream substrates to inactivate glycogen synthesis. Western blot analysis determined that the amount of phosphorylated (inactive) GSK-3 decreased in all five tissues tested in 24 h frozen frogs compared with unfrozen controls. Total GSK-3 protein levels did not change, with the exception of heart GSK-3, indicating that post-translational modification was the primary regulatory mechanism for this kinase. Kinetic properties of skeletal muscle GSK-3 from control and frozen frogs displayed differential responses to a temperature change (22 versus 4°C) and high glucose. For example, when assayed at 4°C, the K(m) for the GSK-3 substrate peptide was ∼44% lower for frozen frogs than the corresponding value in control frogs, indicating greater GSK-3 affinity for its substrates in the frozen state. This indicates that at temperatures similar to the environment encountered by frogs, GSK-3 in frozen frogs will phosphorylate its downstream targets more readily than in unfrozen controls. GSK-3 from skeletal muscle of control frogs was also allosterically regulated. AMP and phosphoenolpyruvate activated GSK-3 whereas inhibitors included glucose, glucose 6-phosphate, pyruvate, ATP, glutamate, glutamine, glycerol, NH(4)Cl, NaCl and KCl. The combination of phosphorylation and allosteric control argues for a regulatory role of GSK-3 in inactivating glycogenesis to preserve high glucose cryoprotectant levels throughout each freezing bout.

  8. [Cardiac electric field at the period of depolarization and repolarization of the frog heart ventricle].

    PubMed

    Vaĭkshnoraĭte, M A; Belogolova, A S; Vitiazev, V A; Azarov, Ia E; Shmakov, D N

    2008-01-01

    Multichannel mapping of electrical field on heart ventricle epicardium and the body surface in frogs Rana esculenta and Rana temporaria was performed at periods of the ventricular myocardium depolarization and repolarization. The zone of the epicardium early depolarization is located on epicardium of the ventricle base posterior wall, while the late depolarization zone--on its apex and on the base anterior wall. The total vector of sequence of the ventricle epicardium depolarization is directed from the base to the apex. The zone of the early repolarization is located in the apical area, while that of the late one--in the area of the base. On the frog body surface the cardioelectric field with the cranial zone of negative and the caudal zone of positive potentials is formed before the appearance of the QRS complex on ECG. At the period of the heart ventricle repolarization the zone of the cardioelectric field negative potentials is located in the cranial, while that of the positive ones--in the body surface caudal parts. The cardioelectric field on the frog body surface at the periods of depolarization and repolarization of the ventricle myocardium reflects adequately the projection of sequence of involvement with excitation and of distribution of potentials on epicardium.

  9. Failure of tetracycline as a biomarker in batch-marking juvenile frogs

    USGS Publications Warehouse

    Hatfield, J.S.; Henry, P.F.P.; Olsen, G.H.; Paul, M.M.; Hammerschlag, R.S.

    2001-01-01

    Recent widespread amphibian declines call for better techniques to assess population dynamics. Tetracycline as a biomarker in capture-recapture studies is one technique used successfully in fish, reptiles, and mammals. A two-phase experimental study was conducted to evaluate tetracycline as a biomarker in green frogs (Rana clamitans) and pickerel frogs (Rana palustris). In the first experimental phase tadpoles were exposed to water containing either 250 mg/l or 500 mg/l tetracycline for a period of 24 hr. During the second phase, juvenile frogs were exposed to tetracycline in water at 500 mg/l or given injections of tetracycline at the dose rate of 100 mg/kg body weight. At selected times several weeks later, under tricaine methanesulfonate anesthesia, a toe was surgically excised from each animal, sectioned and viewed under an ultraviolet microscope. No significant differences were found between the various treatments and control animals (untreated). Therefore, the use of tetracycline as a biomarker in anurans using these techniques is not recommended.

  10. Trichinella britovi in a leopard (Panthera pardus saxicolor) in Iran.

    PubMed

    Mowlavi, Gholamreza; Marucci, Gianluca; Mobedi, Iraj; Zahabiioon, Farzaneh; Mirjalali, Hamed; Pozio, Edoardo

    2009-10-14

    Nematodes of the genus Trichinella are zoonotic parasites with a cosmopolitan distribution. In Iran, these parasites have mainly been detected in carnivorous mammals, yet information on the Trichinella taxa circulating in this country date back to a time when biochemical and molecular tests were not available. We describe the first detection of Trichinella larvae in a leopard (Panthera pardus saxicolor) in Asia and its identification at the species level. The larvae recovered from the leopard muscles were identified as Trichinella britovi using multiplex PCR. The detection of Trichinella infection in a leopard confirms literature data on the high prevalence of infection in carnivorous mammals in Iran.

  11. Personality assessment in snow leopards (Uncia uncia).

    PubMed

    Gartner, Marieke Cassia; Powell, David

    2012-01-01

    Knowledge of individual personality is a useful tool in animal husbandry and can be used effectively to improve welfare. This study assessed personality in snow leopards (Uncia uncia) by examining their reactions to six novel objects and comparing them to personality assessments based on a survey completed by zookeepers. The objectives were to determine whether these methods could detect differences in personality, including age and sex differences, and to assess whether the two methods yielded comparable results. Both keeper assessments and novel object tests identified age, sex, and individual differences in snow leopards. Five dimensions of personality were found based on keepers' ratings: Active/Vigilant, Curious/Playful, Calm/Self-Assured, Timid/Anxious, and Friendly to Humans. The dimension Active/Vigilant was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. Curious/Playful was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. However, other dimensions (Calm/Self-Assured, Friendly to Humans, and Timid/Anxious) did not correlate with novel-object test variables and possible explanations for this are discussed. Thus, some of the traits and behaviors were correlated between assessment methods, showing the novel-object test to be useful in assessing an animal's personality should a keeper be unable to, or to support a keeper's assessment.

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

    PubMed

    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.

  13. Cell proliferation and death in the brain of active and hibernating frogs

    PubMed Central

    Cerri, Silvia; Bottiroli, Giovanni; Bottone, Maria Grazia; Barni, Sergio; Bernocchi, Graziella

    2009-01-01

    ‘Binomial’ cell proliferation and cell death have been studied in only a few non-mammalian vertebrates, such as fish. We thought it of interest to map cell proliferation/apoptosis in the brain of the frog (Rana esculenta L.) as this animal species undergoes, during the annual cycle, physiological events that could be associated with central nervous system damage. Therefore, we compared the active period and the deep underground hibernation of the frog. Using western blot analysis for proliferating cell nuclear antigen (PCNA), we revealed a positive 36 kDa band in all samples and found higher optical density values in the hibernating frogs than in active frogs. In both active and hibernating frogs, we found regional differences in PCNA-immunoreactive cells and terminal transferase dUTP nick-end labelling apoptotic cells in the ventricular zones and parenchyma areas of the main encephalon subdivisions. During the active period of the frogs, the highest concentration of PCNA-immunoreactive cells was found in the ventricle dorsal zone of the cerebral hemispheres but only some of the cells were apoptotic. By contrast, the tectal and cerebellar ventricular zones had a small or medium amount of PCNA-immunoreactive cells, respectively, and a higher number of apoptotic cells. During hibernation, an increased PCNA-immunoreactive cell number was observed in both the brain ventricles and parenchyma compared with active frogs. This increase was primarily evident in the lateral ventricles, a region known to be a proliferation ‘hot spot’. Although differences existed among the brain areas, a general increase of apoptotic cell death was found in hibernating frogs, with the highest number of apoptotic cells being detected in the parenchyma of the cerebral hemispheres and optic tectum. In particular, the increased number of apoptotic cells in the hibernating frogs compared with active frogs in the parenchyma of these brain areas occurred when cell proliferation was higher in

  14. Urea loading enhances freezing survival and postfreeze recovery in a terrestrially hibernating frog.

    PubMed

    Costanzo, Jon P; Lee, Richard E

    2008-09-01

    We tested the hypothesis that urea, an osmolyte accumulated early in hibernation, functions as a cryoprotectant in the freeze-tolerant wood frog, Rana sylvatica. Relative to saline-treated, normouremic (10 micromol ml(-1)) frogs, individuals rendered hyperuremic (70 micromol ml(-1)) by administration of an aqueous urea solution exhibited significantly higher survival (100% versus 64%) following freezing at -4 degrees C, a potentially lethal temperature. Hyperuremic frogs also had lower plasma levels of intracellular proteins (lactate dehydrogenase, creatine kinase, hemoglobin), which presumably escaped from damaged cells, and more quickly recovered neurobehavioral functions following thawing. Experimental freezing-thawing did not alter tissue urea concentrations, but did elevate glucose levels in the blood and organs of all frogs. When measured 24 h after thawing commenced, glucose concentrations were markedly higher in urea-loaded frogs as compared to saline-treated ones, possibly because elevated urea retarded glucose clearance. Like other low-molecular-mass cryoprotectants, urea colligatively reduces both the amount of ice forming within the body and the osmotic dehydration of cells. In addition, by virtue of certain non-colligative properties, it may bestow additional protection from freeze-thaw damage not afforded by glucose.

  15. DNA repair and resistance to UV-B radiation in western spotted frogs

    USGS Publications Warehouse

    Blaustein, A.R.; Hays, J.B.; Hoffman, P.D.; Chivers, D.P.; Kiesecker, J.M.; Leonard, W.P.; Marco, A.; Olson, D.H.; Reaser, J.K.; Anthony, R.G.

    1999-01-01

    We assessed DNA repair and resistance to solar radiation in eggs of members of the western spotted frog complex (Rana pretiosa and R. luteiventris), species whose populations are suffering severe range reductions and declines. Specifically, we measured the activity of photoreactivating enzyme (photolyase) in oocytes of spotted frogs. In some species, photoreactivation is the most important mechanism for repair of UV-damaged DNA. Using field experiments, we also compared the hatching success of spotted frog embryos at natural oviposition sites at three elevations, where some embryos were subjected to ambient levels of UV-B radiation and others were shielded from UV-B radiation. Compared with other amphibians, photolyase activities in spotted frogs were relatively high. At all sites, hatching success was unaffected by UV-B. Our data support the interpretation that amphibian embryos with relatively high levels of photolyase are more resistant to UV-B radiation than those with lower levels of photolyase. At the embryonic stage, UV-B radiation does not presently seem to be contributing to the population declines of spotted frogs.

  16. Consequences of intraspecific niche variation: phenotypic similarity increases competition among recently metamorphosed frogs.

    PubMed

    Benard, Michael F; Middlemis Maher, Jessica

    2011-07-01

    Phenotype is often correlated with resource use, which suggests that as phenotypic variation in a population increases, intraspecific competition will decrease. However, few studies have experimentally tested the prediction that increased intraspecific phenotypic variation leads to reduced competitive effects (e.g., on growth rate, survival or reproductive rate). We investigated this prediction with two experiments on wood frogs (Rana sylvatica). In the first experiment, we found that a frog's size was positively correlated with the size of its preferred prey, indicating that the feeding niche of the frogs changed with size. In the second experiment, we used an experimental design in which we held the initial mass of "focal" frogs constant, but varied the initial mass of their competitors. We found a significant quadratic effect of the average mass of competitors: focal frog growth was lowest when raised with similar-sized competitors, and highest when raised with competitors that were larger or smaller. Our results demonstrate that growth rates increase (i.e., competitive intensity decreases) when individuals are less similar to other members of the population and exhibit less overlap in resource use. Thus, changes in the amount of phenotypic variation in a population may ultimately affect population-level processes, such as population growth rate and extinction risk.

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

    PubMed

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments.

  18. Actions of antidiuretic hormone analogues on intact and nystatin-permeabilized frog skins.

    PubMed

    Jared, Silviya Rajakumari; Rao, J Prakasa; Subramani, Sathya

    2009-12-01

    The roles of two antidiuretic hormone analogues, namely arginine vasotocin (AVT) and lysine vasopressin (LVP), in solute transport across the ventral abdominal skin of frogs (Rana hexadactyla) were studied using voltage-clamp methods on intact and nystatin-permeabilized preparations. Arginine vasotocin (40 nm), the amphibian analogue of antidiuretic hormone, did not have any effect on the skin of Rana hexadactyla. However, LVP, the porcine antidiuretic hormone, increased the transepithelial potential difference (TEPD) and short-circuit current (SCC) significantly, without affecting the slope conductance. Lysine vasopressin had no action subsequent to addition of amiloride (100 microm) on the apical side or ouabain (10 microm) on the basolateral side. Lysine vasopressin increased slope conductance in the nystatin-permeablized skin while decreasing TEPD. Such a change was not seen in chloride-free solutions. To elucidate the mechanism of action of LVP on intact skin, experiments were done with forskolin and a V(2) receptor blocker. The effects of forskolin (10 microm) were different from those of LVP in that forskolin significantly increased SCC and conductance of the intact skin, while decreasing TEPD. The forskolin-induced increase in conductance was not abolished by amiloride. Use of the V(2) receptor blocker inhibited the effects of LVP. We conclude that AVT does not have an action on the skin of Rana hexadactyla. Lysine vasopressin enhances transepithelial sodium transport by increasing sodium-potassium pump activity, while not affecting the epithelial sodium channel conductance. Lysine vasopressin also enhances an inward-directed conductance on the basolateral membrane, probably a chloride conductance. The action of LVP on the intact frog skin is through the V(2) receptors; however, downstream signalling does not seem to be mediated by cAMP. Analysis of the electrophysiological model of frog skin with LVP allows us additionally to conclude that modulation of

  19. Congenital ankyloblepharon in a leopard gecko (Eublepharis macularius).

    PubMed

    Rival, Franck

    2015-01-01

    A 6-month-old leopard gecko with unilateral partially fused eyelids since birth was presented for examination. A diagnosis of congenital ankyloblepharon was made and surgical correction was performed successfully.

  20. Pathological findings of a fatal leopard seal attack.

    PubMed

    Rutty, Guy N

    2007-03-01

    A unique case of a fatal leopard seal attack against an adult human female is presented. The death occurred in Rothera, Antarctica when the female was snorkeling while undertaking scientific research. The principle injuries occurred, during life, to the facial areas prior to the act of drowning. The method of attack of leopard seals against their natural prey is discussed and related to the findings on the deceased.

  1. Transcript expression of the freeze responsive gene fr10 in Rana sylvatica during freezing, anoxia, dehydration, and development.

    PubMed

    Sullivan, K J; Biggar, K K; Storey, K B

    2015-01-01

    Freeze tolerance is a critical winter survival strategy for the wood frog, Rana sylvatica. In response to freezing, a number of genes are upregulated to facilitate the survival response. This includes fr10, a novel freeze-responsive gene first identified in R. sylvatica. This study analyzes the transcriptional expression of fr10 in seven tissues in response to freezing, anoxia, and dehydration stress, and throughout the Gosner stages of tadpole development. Transcription of fr10 increased overall in response to 24 h of freezing, with significant increases in expression detected in testes, heart, brain, and lung when compared to control tissues. When exposed to anoxia; heart, lung, and kidney tissues experienced a significant increase, while the transcription of fr10 in response to 40% dehydration was found to significantly increase in both heart and brain tissues. An analysis of the transcription of fr10 throughout the development of the wood frog showed a relatively constant expression; with slightly lower transcription levels observed in two of the seven Gosner stages. Based on these results, it is predicted that fr10 has multiple roles depending on the needs and stresses experienced by the wood frog. It has conclusively been shown to act as a cryoprotectant, with possible additional roles in anoxia, dehydration, and development. In the future, it is hoped that further knowledge of the mechanism of action of FR10 will allow for increased stress tolerance in human cells and tissues.

  2. Preventive effect of some substances on experimental oxalic calculogenesis in the frog.

    PubMed

    Sorrentino, F; Fella, A; Pota, A

    1981-01-01

    Rana esculenta tadpoles that are fed spinach develop an oxalic calculogenesis. The addition of cholestyramine, orthophosphate, citrate, allopurinol and tungstate to the tank water prevented calculi formation while succinimide, magnesium oxide, hydrochlorothiazide and tetracycline were ineffective. Methylene blue proved lethal to tadpoles, and its anti-lithogenic activity could not be assessed. These findings, except for the non-effectiveness of magnesium oxide, are in agreement with both the theoretical expectations and the results obtained in other experimental models. Experimental frog calculogenesis seems to be a simple and valid method for evaluating anti-lithogenic activity.

  3. Gastroesophageal intussusception in a leopard (Panthera pardus).

    PubMed

    Hettlich, Bianca F; Hobson, H Phil; Snakard, Eileen P; Johnson, James H

    2010-09-01

    An 8-yr-old male leopard (Panthera pardus) was presented with a 4-day history of lethargy, vomiting, and anorexia. Thoracic and abdominal radiographs revealed a soft-tissue mass cranial to the diaphragm and atypical appearance of the gastric fundus. Esophagoscopy revealed gastric mucosa in the lumen of the esophagus, which confirmed gastroesophageal intussusception. An exploratory celiotomy with manual reduction of the intussusception was performed. Reduction was verified by intraoperative esophagoscopy and gastroscopy. An incisional fundic gastropexy to the left abdominal wall was performed to reduce the chance of a recurrence of the intussusception. No postoperative complications related to the surgery were observed, and the animal resumed eating within 48 hr of surgery. A subsequent recurrence of clinical signs was not noted by the owner.

  4. Jan Swammerdam's frogs

    PubMed Central

    Sleigh, Charlotte

    2012-01-01

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

  5. Calcium oxalate nephrolithiasis and tubular necrosis in recent metamorphs of Rana sylvatica (Lithobates sylvaticus) fed spinach during the premetamorphic (tadpole) stage.

    PubMed

    Forzán, M J; Ferguson, L V; Smith, T G

    2015-03-01

    Amphibians in the family Ranidae (true frogs) seem highly susceptible to oxalosis, particularly when fed a diet high in oxalic acid during the premetamorphic (tadpole) stage. The authors describe the mortality of 150 captive-raised wood frogs (Rana sylvatica or Lithobates sylvaticus) from oxalate nephrolithiasis and renal tubular necrosis caused by consumption of boiled spinach during tadpole development. Renal lesions were due to intraluminal transparent crystals which were birefringent under polarized light and were identified morphologically and histochemically as composed of calcium oxalate. Evidence of early fibrosis or squamous metaplasia, and a presentation at least 2 weeks after spinach consumption had ended, suggested a subacute course. Tadpole-feeding protocols should avoid plants with high oxalate content (eg, spinach and rhubarb leaves), and any episode of high mortality in captive amphibians along with nephrolithiasis should prompt an evaluation of the feed sources for material with high oxalate content.

  6. Cryoprotectants and Extreme Freeze Tolerance in a Subarctic Population of the Wood Frog

    PubMed Central

    Costanzo, Jon P.; Reynolds, Alice M.; do Amaral, M. Clara F.; Rosendale, Andrew J.; Lee, Richard E.

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to –8°C, either directly or following three cycles of freezing/thawing between –4 and 0°C, or –16°C increased the liver’s synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica. PMID:25688861

  7. Bioaccumulation of selenium by snakes and frogs in the San Joaquin Valley, California

    USGS Publications Warehouse

    Ohlendorf, H.M.; Hothem, R.L.; Aldrich, T.W.

    1988-01-01

    Livers of gopher snakes (Pituophis melanoleucus) from Kesterson Reservoir (Merced County, California) contained significantly higher mean selenium concentrations (11.1 .mu.g/g, dry weight) than those from two nearby reference sites (2.05 and 2.14 .mu.g/g). Livers of bullfrogs (Rana catesbeiana) collected from the San Luis Drain at Kersterson Reservoir also contained significantly higher mean selenium concentrations (45.0 .mu.g/g) than those from nearby reference sites (6.22 .mu.g/g). The high levels of selenium bioaccumulation in these snakes and frogs at Kersterson Reservoir reflected the elevated levels found in their food organisms. We did not examine that snakes or frogs from Kesterson for signs of ill health, but the concentrations we found were sufficiently high to warrant concern about potential adverse effects in these animals and their predators.

  8. A genetic component of resistance to fungal infection in frog embryos

    PubMed Central

    Sagvik, Jörgen; Uller, Tobias; Olsson, Mats

    2008-01-01

    The embryo has traditionally been considered to completely rely upon parental strategies to prevent threats to survival posed by predators and pathogens, such as fungi. However, recent evidence suggests that embryos may have hitherto neglected abilities to counter pathogens. Using artificial fertilization, we show that among-family variation in the number of Saprolegnia-infected eggs and embryos in the moor frog, Rana arvalis, cannot be explained by maternal effects. However, analysed as a within-females effect, sire identity had an effect on the degree of infection. Furthermore, relatively more eggs and embryos were infected when eggs were fertilized by sperm from the same, compared with a different, population. These effects were independent of variation in fertilization success. Thus, there is likely to be a significant genetic component in embryonic resistance to fungal infection in frog embryos. Early developmental stages may show more diverse defences against pathogens than has previously been acknowledged. PMID:18319211

  9. A genetic component of resistance to fungal infection in frog embryos.

    PubMed

    Sagvik, Jörgen; Uller, Tobias; Olsson, Mats

    2008-06-22

    The embryo has traditionally been considered to completely rely upon parental strategies to prevent threats to survival posed by predators and pathogens, such as fungi. However, recent evidence suggests that embryos may have hitherto neglected abilities to counter pathogens. Using artificial fertilization, we show that among-family variation in the number of Saprolegnia-infected eggs and embryos in the moor frog, Rana arvalis, cannot be explained by maternal effects. However, analysed as a within-females effect, sire identity had an effect on the degree of infection. Furthermore, relatively more eggs and embryos were infected when eggs were fertilized by sperm from the same, compared with a different, population. These effects were independent of variation in fertilization success. Thus, there is likely to be a significant genetic component in embryonic resistance to fungal infection in frog embryos. Early developmental stages may show more diverse defences against pathogens than has previously been acknowledged.

  10. It's a Frog's Life

    ERIC Educational Resources Information Center

    Coffey, Audrey L.; Sterling, Donna R.

    2003-01-01

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

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

    PubMed

    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.

  12. Molecular evidence for species-level distinctions in clouded leopards.

    PubMed

    Buckley-Beason, Valerie A; Johnson, Warren E; Nash, Willliam G; Stanyon, Roscoe; Menninger, Joan C; Driscoll, Carlos A; Howard, JoGayle; Bush, Mitch; Page, John E; Roelke, Melody E; Stone, Gary; Martelli, Paolo P; Wen, Ci; Ling, Lin; Duraisingam, Ratna K; Lam, Phan V; O'Brien, Stephen J

    2006-12-05

    Among the 37 living species of Felidae, the clouded leopard (Neofelis nebulosa) is generally classified as a monotypic genus basal to the Panthera lineage of great cats. This secretive, mid-sized (16-23 kg) carnivore, now severely endangered, is traditionally subdivided into four southeast Asian subspecies (Figure 1A). We used molecular genetic methods to re-evaluate subspecies partitions and to quantify patterns of population genetic variation among 109 clouded leopards of known geographic origin (Figure 1A, Tables S1 ans S2 in the Supplemental Data available online). We found strong phylogeographic monophyly and large genetic distances between N. n. nebulosa (mainland) and N. n. diardi (Borneo; n = 3 individuals) with mtDNA (771 bp), nuclear DNA (3100 bp), and 51 microsatellite loci. Thirty-six fixed mitochondrial and nuclear nucleotide differences and 20 microsatellite loci with nonoverlapping allele-size ranges distinguished N. n. nebulosa from N. n. diardi. Along with fixed subspecies-specific chromosomal differences, this degree of differentiation is equivalent to, or greater than, comparable measures among five recognized Panthera species (lion, tiger, leopard, jaguar, and snow leopard). These distinctions increase the urgency of clouded leopard conservation efforts, and if affirmed by morphological analysis and wider sampling of N. n. diardi in Borneo and Sumatra, would support reclassification of N. n. diardi as a new species (Neofelis diardi).

  13. Implications of spatial genetic patterns for conserving African leopards.

    PubMed

    Ropiquet, Anne; Knight, Andrew T; Born, Céline; Martins, Quinton; Balme, Guy; Kirkendall, Lawrence; Hunter, Luke; Senekal, Charl; Matthee, Conrad A

    2015-11-01

    The leopard (Panthera pardus) is heavily persecuted in areas where it predates livestock and threatens human well-being. Attempts to resolve human-leopard conflict typically involve translocating problem animals; however, these interventions are rarely informed by genetic studies and can unintentionally compromise the natural spatial genetic structure and diversity, and possibly the long-term persistence, of the species. No significant genetic discontinuities were definable within the southern African leopard population. Analysis of fine-scale genetic data derived from mitochondrial and nuclear DNA revealed that the primary natural process shaping the spatial genetic structure of the species is isolation-by-distance (IBD). The effective gene dispersal (σ) index can inform leopard translocations and is estimated to be 82 km for some South African leopards. The importance of adopting an evidence-based strategy is discussed for supporting the integration of genetic data, spatial planning and social learning institutions so as to promote collaboration between land managers, government agency staff and researchers.

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

    PubMed Central

    McCaffery, Rebecca M.; Maxell, Bryce A.

    2010-01-01

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

  15. Managing habitat to slow or reverse population declines of the Columbia spotted frog in the Northern Great Basin

    USGS Publications Warehouse

    Pilliod, David S.; Richard D. Scherer,

    2015-01-01

    Evaluating the effectiveness of habitat management actions is critical to adaptive management strategies for conservation of imperiled species. We quantified the response of a Great Basin population of the Columbia spotted frog (Rana luteiventris) to multiple habitat improvement actions aimed to reduce threats and reverse population declines. We used mark-recapture data for 1,394 adult frogs that had been marked by state, federal, and university biologists in 9 ponds representing a single population over a 16-year period from 1997 to 2012. With the use of demographic models, we assessed population-level effects of 1) a grazing exclosure constructed around 6 stock ponds that had been used to water livestock for decades before being fully fenced in 2003, and 2) the construction of 3 new stock ponds in 2003 to provide alternative water sources for livestock and, secondarily, to provide additional frog habitat. These management actions were implemented in response to a decline of more than 80% in population size from 1997 to 2002. We found evidence that excluding cattle from ponds and surrounding riparian habitats resulted in higher levels of frog production (more egg masses), higher adult frog recruitment and survival, and higher population growth rate. We also found that frogs colonized the newly constructed stock ponds within 3 years and frogs began breeding in 2 of them after 5 years. The positive effects of the cattle exclosure and additional production from the new ponds, although notable, did not result in full recovery of the population even 9 years later. This slow recovery may be partly explained by the effects of weather on recruitment rates, particularly the negative effects of harsher winters with late springs and higher fall temperatures. Although our findings point to potential successes of habitat management aimed at slowing or reversing rapidly declining frog populations, our study also suggests that recovering from severe population declines can take

  16. Activation and repolarization patterns in the ventricular epicardium under sinus rhythm in frog and rabbit hearts.

    PubMed

    Azarov, Jan E; Shmakov, Dmitry N; Vityazev, Vladimir A; Roshchevskaya, Irina M; Roshchevsky, Mikhail P

    2007-03-01

    Our study compared the contributions of activation sequence and local repolarization durations distribution in the organization of epicardial repolarization in animals with fast (rabbit) and slow (frog) myocardial activation under sinus rhythm. Activation times, repolarization times and activation-recovery intervals (ARI) were obtained from ventricular epicardial unipolar electrograms recorded in 13 Chinchilla rabbits (Oryctolagus cuniculus) and 10 frogs (Rana temporaria). In frogs, depolarization travels from the atrioventricular ring radially. ARIs increased progressively from the apex to the middle portion and finally to the base (502+/-75, 557+/-73, 606+/-79 ms, respectively; P<0.01). In rabbits, depolarization spread from two epicardial breakthroughs with the duration of epicardial activation being lower than that in frogs (17+/-3 vs. 44+/-18 ms; P<0.001). ARI durations were 120+/-37, 143+/-45, and 163+/-40 ms in the left ventricular apex, left, and right ventricular bases, respectively (P<0.05). In both species, repolarization sequence was directed from apex to base according to the ARI distribution with dispersion of repolarization being higher than that of activation (P<0.001). Thus, excitation spread sequence and velocity per se do not play a crucial role in the formation of ventricular epicardial repolarization pattern, but the chief factor governing repolarization sequences is the distribution of local repolarization durations.

  17. Expression analysis and identification of antimicrobial peptide transcripts from six North American frog species

    USGS Publications Warehouse

    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.

  18. Bioaccumulation, maternal transfer and elimination of polybrominated diphenyl ethers in wild frogs.

    PubMed

    Liu, Peng-Yan; Du, Guo-Dong; Zhao, Ya-Xian; Mu, Yun-Song; Zhang, Ai-Qian; Qin, Zhan-Fen; Zhang, Xiao-You; Yan, Shi-Shuai; Li, Yan; Wei, Rong-Guo; Qin, Xiao-Fei; Yang, Yong-Jian

    2011-08-01

    To investigate bioaccumulation, maternal transfer and elimination of polybrominated diphenyl ethers (PBDEs) in amphibians, we collected adult frogs (Rana limnocharis) from a rice field in an e-waste recycling site in China. We found that ∑PBDEs in the whole frogs and various tissues (brain, liver, testis and egg) ranged from 17.10 to 141.11 ng g(-1) wet weight. Various tissues exhibited a similar PBDE congener profile, which was characterized by intermediate brominated congeners (BDE-99 and BDE-153) as the largest contributors, with less lower brominated congeners (BDE-28 and BDE-47) and higher brominated congeners (BDE-209). The maternal transfer capacity of PBDEs declined with the increase in bromine numbers of PBDE congeners. We suggest that the bromine atom number (the molecular size, to some degree) might be a determining factor for the maternal transport of a PBDE congener rather than K(ow) (Octanol-Water partition coefficient), which expresses a compound's lipophilicity. ∑PBDEs concentrations in frogs decreased over time during a depuration period of 54 days when these wild frogs were brought to the lab from the e-waste recycling site. The half-life of ∑PBDEs was 35 days, with about 14 days for BDE-47, and 36 and 81 days for BDE-99 and BDE-153, respectively. The data shows that the elimination of PBDEs has no essential difference from aquatic and terrestrial species.

  19. Propulsive force calculations in swimming frogs. II. Application of a vortex ring model to DPIV data.

    PubMed

    Stamhuis, Eize J; Nauwelaerts, Sandra

    2005-04-01

    Frogs propel themselves by kicking water backwards using a synchronised extension of their hind limbs and webbed feet. To understand this propulsion process, we quantified the water movements and displacements resulting from swimming in the green frog Rana esculenta, applying digital particle image velocimetry (DPIV) to the frog's wake. The wake showed two vortex rings left behind by the two feet. The rings appeared to be elliptic in planform, urging for correction of the observed ring radii. The rings' long and short axes (average ratio 1.75:1) were about the same size as the length and width of the propelling frog foot and the ellipsoid mass of water accelerated with it. Average thrust forces were derived from the vortex rings, assuming all propulsive energy to be compiled in the rings. The calculated average forces (F(av)=0.10+/-0.04 N) were in close agreement with our parallel study applying a momentum-impulse approach to water displacements during the leg extension phase. We did not find any support for previously assumed propulsion enhancement mechanisms. The feet do not clap together at the end of the power stroke and no "wedge-action" jetting is observed. Each foot accelerates its own water mantle, ending up in a separate vortex ring without interference by the other leg.

  20. Proposed method for evaluating the effects of PCBs in sediment on egg mass viability and reproductive success in frogs

    SciTech Connect

    Schmidt, C.S.; Henning, M.H.; Ebert, E.S.

    1995-12-31

    A proposed study design for evaluating the effect of PCBs in the sediments of a large New England river on reproductive success in frogs is described. Depending on field conditions and species abundance, the study will use either bullfrogs, Rana catesbiana; spring peepers, Hyla pickeringii; or green frogs, Rana claymitans as the study model. A selected number of gravid females will be collected from both the target area and a reference area matched with respect to a number of key variables including, but not limited to, stream flow, temperature, pH, substrate type, depth, surrounding land use, and organic carbon content of sediments. The gravid frogs will be transferred to a laboratory, where the egg masses will be stripped following induced ovulation, and then fertilized using semen from males collected in the field. Egg masses will be maintained under static renewal conditions for a period up to and including 7 days post hatch, during which mortality and gross morphological appearance will be evaluated. In the event that statistically significant differences in these endpoints are noted, a dose response model will be developed to relate observed effects to previously determined PCB concentrations in egg masses and maternal tissues. The results of this study will be of significant utility in evaluating reproductive toxicity of PCBs in ecological risk assessment.

  1. TOXICITY AND BIOACCUMULATION OF PFOS IN A PARTIAL LIFE CYCLE TEST WITH THE NORTHERN LEOPARD FROG

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer actively manufactured, the global distribution and relative persistence of PFOS indicates a need to...

  2. Changes in growth rate and macroelement and trace element accumulation in Hydrocharis morsus-ranae L. during the growing season in relation to environmental contamination.

    PubMed

    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.

  3. Operation of the Lectric Leopard. Final report

    SciTech Connect

    Kamm, I.O.

    1981-07-01

    The vehicle selected for the demonstration project is a Lectric Leopard built by US Electricar Corporation. The vehicle was unable to fulfill the intentions of the program because of continuous failures in the control system and an inability of the factory to fix them. Our requests to obtain circuit diagrams of the system so that we could make repairs ourselves were turned down, stating that this information was proprietary. The vehicle was demonstrated three times, to a student audience, Public Service Electric and Gas Company Day at Stevens and the Rotary Club of Hoboken; but because of the large amounts of downtime the vehicle only accumulated 900 miles over a one year period. In May 1981 we were informed that in a frontal barrier test, the rear batteries had broken loose delivering a second impact on the driver and dumping several gallons of acid into the occupant compartment. On the advise of DOE the vehicle has not been used since. If Stevens is permitted to keep the vehicle it is our intent to make it the subject of several student senior design projects to make the vehicle safe for use by containerizing the rear batteries.

  4. Rates of development in male and female Wood Frogs and patterns of parasitism by lung nematodes.

    PubMed

    Dare, O K; Forbes, M R

    2008-03-01

    Researchers are becoming interested in testing whether investment in growth and/or development trades off against investment in parasite defence. We tested this idea by examining relations between development of Wood Frogs (Rana sylvatica) and susceptibility to lung nematodes (Rhabdias ranae). Male and female frogs reared in outdoor mesocosms were the same length and mass at metamorphosis. However, males metamorphosed sooner than females. Lung nematodes were no more likely to penetrate male versus female metamorphs following controlled exposures, but males had higher intensities of adult female worms and the largest worms per host were, on average, of larger size in male metamorphs. Males that took longer to metamorphose carried higher numbers of worms in their lungs than males that metamorphosed early. In comparison, females that developed faster harboured more worms in their lungs than females that took longer to reach metamorphosis. Our results suggest that variation in susceptibility to lung nematodes is influenced by host sex and possibly also by sex-specific relations with developmental rate. Further, male hosts might prove to be a more important source of infective stages of worms than female hosts.

  5. Declines of the California red-legged frog: Climate, UV-B, habitat, and pesticides hypotheses

    USGS Publications Warehouse

    Davidson, C.; Shaffer, H.B.; Jennings, M.R.

    2001-01-01

    The federally threatened California red-legged frog (Rana aurora draytonii) has disappeared from much of its range for unknown reasons. We mapped 237 historic locations for the species and determined their current population status. Using a geographic information system (GIS), we determined latitude, elevation, and land use attributes for all sites and analyzed the spatial pattern of declines. We then compared the observed patterns of decline to those predicted by the climate change, UV-B radiation, pesticides, and habitat alteration hypotheses for amphibian decline. Declines were not consistent with the climate change hypothesis but showed a strong positive association with elevation, percentage upwind agricultural land use, and local urbanization. These results apply to patterns of decline across the entire range of R. a. draytonii in California, as well as within geographic subregions. The elevational gradient in declines is consistent with the UV-B hypothesis, although the UV-B hypothesis also predicts a north-to-south gradient in declines, which we did not observe. The association of declines with the amount of upwind agricultural land use strongly suggests that wind-borne agrochemicals may be an important factor in declines. This association was most pronounced within the Central Valley-Sierra region, where other studies have documented both transport and deposition of pesticides to the Sierra Nevada and the presence of pesticide residues in the bodies of congeneric (Rana muscosa) and more distantly related (Hyla regilla) frog species.

  6. Multiple ocular colobomas in the snow leopard (Uncia uncia).

    PubMed

    Barnett, K C; Lewis, J C M

    2002-09-01

    Two singleton female snow leopard cubs are reported with bilateral central upper lid colobomas. In addition, one cub had a coloboma of the fundus in one eye extending from the lower optic disc region. Surgical treatment by wedge resection was successful in both cases. Details of ocular colobomas in other snow leopards reported in the literature are described and it is suggested that the exact etiology of the condition in this species may be discovered by further study of similar colobomas in the domestic cat.

  7. Verification Tests of the US Electricar Corp. Lectric Leopard.

    DTIC Science & Technology

    1980-10-01

    ASTRACr eftwen as rewee eIN and IF~~ by bloek umber) TheMS e~eua. .’Letri Lopadj a eault Le Car that has been converted to an electric vehicle. It was...34Perfor- mance Standards for Demonstrations." IV. TEST VEHICLE DESCRIPTION The Electricar Lectric Leopard is a standard Renault Le Car Passenger car ...a 12-hp, compound-wound d.c. motor manufactured by Prestolite Corporation. The Leopard has the standard Renault Le Car torsion bar suspen- sion

  8. Evidence of leopard predation on bonobos (Pan paniscus).

    PubMed

    D'Amour, Danielle E; Hohmann, Gottfried; Fruth, Barbara

    2006-01-01

    Current models of social organization assume that predation is one of the major forces that promotes group living in diurnal primates. As large body size renders some protection against predators, gregariousness of great apes and other large primate species is usually related to other parameters. The low frequency of observed cases of nonhuman predation on great apes seems to support this assumption. However, recent efforts to study potential predator species have increasingly accumulated direct and indirect evidence of predation by leopards (Panthera pardus) on chimpanzees and gorillas. The following report provides the first evidence of predation by a leopard on bonobos (Pan paniscus).

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

    PubMed

    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.

  10. Landscape genetics of high mountain frog metapopulations

    USGS Publications Warehouse

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

    2010-01-01

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

  11. Landscape genetics of high mountain frog metapopulations.

    PubMed

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

    2010-09-01

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

  12. [Effect of some antibiotics on semi-circular canal activity in the frog (Rana esculenta)].

    PubMed

    Gallais, A; Gribenski, A

    1975-01-01

    We have studied the action of two ototoxic antibiotics (streptomycin and gentamycin) on the activity of the horizontal semicircular canal in comparison with those of penicillin and 7 g/1 NaCl solution, all of them being injected into the labyrinthic cavity. Only streptomycin and gentamycin have a specific action, and the one of streptomycin is much more important than the one of gentamycin.

  13. [Response of efferent vestibular fibers to horizontal rotation in frogs (Rana esculenta L.)].

    PubMed

    Caston, J; Gribenski, A

    1975-01-01

    The activity of efferent vestibular fibres has been recorded on the nerve of the left vertical anterior semicircular canal detached from its ampulla during rotations in the horizontal plane. Different types of responses have been found; they are noted in table I and pictured on fig. 2.

  14. Defrosting Polar Dunes--'The Snow Leopard'

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The patterns created by dark spots on defrosting south polar dunes are often strange and beautiful. This picture, which the Mars Orbiter Camera team has dubbed, 'the snow leopard,' shows a dune field located at 61.5oS, 18.9oW, as it appeared on July 1, 1999. The spots are areas where dark sand has been exposed from beneath bright frost as the south polar winter cap begins to retreat. Many of the spots have a diffuse, bright ring around them this is thought to be fresh frost that was re-precipitated after being removed from the dark spot. The spots seen on defrosting polar dunes are a new phenomenon that was not observed by previous spacecraft missions to Mars. Thus, there is much about these features that remains unknown. For example, no one yet knows why the dunes become defrosted by forming small spots that grow and grow over time. No one knows for sure if the bright rings around the dark spots are actually composed of re-precipitated frost. And no one knows for sure why some dune show spots that appear to be 'lined-up' (as they do in the picture shown here).

    This Mars Global Surveyor Mars Orbiter Camera image is illuminated from the upper left. North is toward the upper right. The scale bar indicates a distance of 200 meters (656 feet).

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

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

    USGS Publications Warehouse

    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.

  16. Surface ultrastructure of the cornea and adjacent epidermis during metamorphosis of Rana pipiens: a scanning electron microscopic study

    SciTech Connect

    Kaltenbach, J.C.; Harding, C.V.; Susan, S.

    1980-01-01

    The external surface of the cornea and adjacent epidermis of larvae in representative developmental stages and of adult frogs, Rana pipiens, was studied by scanning electron microscopy. Surface cells are polygonal, usually hexagonal, in outline and covered with microprojections. During larval development prior to metamorphic stages, neither eyelids nor Harderian glands have developed; microprojections on the corneal surface are high and branched, and cell boundaries are elevated. On the anterior portion of the cornea and on the epidermis near the eye, the surface pattern is less dense, and ciliated cells are present. During metamorphic stages, corneal cell boundaries become less prominent and the pattern of microprojections more variable and markedly different from that of larvae of earlier stages. Corneal cells have a spongy appearance, are covered by a coating material, or are characterized as light or dark based on their brightness and surface texture. As eyelids develop in metamorphic stages XX-XXI, the numbers of ciliated cells increase dramatically, both on the corneal surface and on the edges of the developing lids. In later metamorphic stages XXII to XXV, lids and Harderian glands become well-developed, and cilia are no longer observed. The adjacent epidermal surface becomes devoid of cilia but perforated by openings of cutaneous glands. Its spongy appearance is similar to that of both the cornea and neighboring epidermis of the mature frog. Changes in corneal surface features are probably metamorphic events associated with development of lids and Harderian glands and a shift from an aqueous to an air environment.

  17. Effect of constant and fluctuating temperature on daily melatonin production by eyecups from Rana perezi.

    PubMed

    Valenciano, A I; Alonso-Gómez, A L; Alonso-Bedate, M; Delgado, M J

    1997-04-01

    We analysed the effect of daily temperature cycles in relation to constant temperature on day/night melatonin synthesis in frog eyecups in culture. Eyecups were cultured for 24 h under 12L:12D photoperiod and two thermal regimes, constant temperature (25, 15 and 5 degrees C) and thermoperiod (WL/CD, thermophase coinciding with photophase and cryophase coinciding with scotophase; and CL/WD, cryophase coinciding with photophase and thermophase coinciding with scotophase). A negative correlation between ocular serotonin N-acetyltransferase activity and culture temperature for both diurnal and nocturnal activities has been observed. This effect of increased ocular activity at low temperature is more pronounced than the well-known stimulatory effect of darkness, and it does not depend on the photoperiod phase. The lack of interactions between the phase of photoperiod and culture temperature indicates that the effects of both factors are independent. Night-time temperature is the key factor in determining the amplitude of the melatonin rhythm in the Rana perezi retina. However, daytime temperature can not counteract the inhibitory effect of light on ocular melatonin synthesis.

  18. Inhibitor and temperature effect on catalase in the liver of adult diploid and haploid Rana rugosa.

    PubMed

    Kashiwagi, A; Kashiwagi, K; Takase, M; Hanada, H; Yamashita, M; Naitoh, T; Nakamura, M

    1998-01-01

    The authors succeeded in raising a single mature haploid Rana rugosa female to the age of 2 years from an egg artificially fertilized with ultraviolet-irradiated sperm. In order to discover why this particular haploid individual should survive so long, hydrogen peroxide detoxifying catalase in the liver of this individual and age-matched diploids was examined and compared for total activity, temperature stability, and chemical inhibition. Total activity was found to be significantly higher in the haploid frog than in the diploids, suggesting that this particular haploid had a unique system for hydrogen peroxide detoxification which protected the liver against cell death, preventing hepatic failure, and leading to a prolonged survival. Liver catalase from the haploid proved to be more labile to aminotriazole and urea, losing 60-70% of its original activity after 30 min treatment, whereas diploid catalase lost only 40% under the same conditions. Haploid and diploid catalase responded similarly to heat, however. It seems likely that inhibitor-binding sites differ considerably between the catalase of normal diploids and the catalase of this particular haploid, while overall structure is generally similar.

  19. Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

    PubMed Central

    Shu, Longfei; Laurila, Anssi; Räsänen, Katja

    2015-01-01

    Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

  20. Novel family of antimicrobial peptides from the skin of Rana shuchinae.

    PubMed

    Zheng, Ruiqiang; Yao, Bin; Yu, Haining; Wang, Hanjin; Bian, Jianmin; Feng, Feifei

    2010-09-01

    So far numerous antimicrobial peptides have been characterized from amphibians. In this work, a new family of antimicrobial peptides, named shuchin, was purified and characterized from skin secretions of the frog, Rana shuchinae that lives in freezing mountains. Totally two members of shuchin (shuchin 1 and 2) were identified with the amino acid sequence of NALSMPRNKCNRALMCFG and NALSSPRNKCDRASSCFG, respectively. cDNAs encoding shuchins were cloned from the skin cDNA library of R. shuchinae. The precursors of shuchin are composed of 62 amino acid residues including the conserved signal peptides, acidic propieces, and mature antimicrobial peptides. Synthetic shuchins showed strong and broad antimicrobial activities against Gram-positive bacteria (Staphylococcus aureus, and Bacillus cereus; MICs<12.5 microg/ml), Gram-negative bacteria (Escherichia coli, Bacillus dysenteriae, Pseudomonas aeruginosa; most MICs from 3.1 to 12.5 microg/ml), and yeast (Candida albicans; MICs of 6.25 microg/ml), but no hemolytic activity under the effective concentration, thereby provide more leading templates for designing novel anti-infection agents.

  1. Population differentiation in G matrix structure due to natural selection in Rana temporaria.

    PubMed

    Cano, José Manuel; Laurila, Anssi; Pało, Jukka; Merilä, Juha

    2004-09-01

    The additive genetic variance-covariance matrix (G) is a concept central to discussions about evolutionary change over time in a suite of traits. However, at the moment we do not know how fast G itself changes as a consequence of selection or how sensitive it is to environmental influences. We investigated possible evolutionary divergence and environmental influences on G using data from a factorial common-garden experiment where common frog (Rana temporaria) tadpoles from two divergent populations were exposed to three different environmental treatments. G-matrices were estimated using an animal model approach applied to data from a NCII breeding design. Matrix comparisons using both Flury and multivariate analysis of variance methods revealed significant differences in G matrices both between populations and between treatments within populations, the former being generally larger than the latter. Comparison of levels of population differentiation in trait means using Q(ST) indices with that observed in microsatellite markers (F(ST)) revealed that the former values generally exceeded the neutral expectation set by F(ST). Hence, the results suggest that intraspecific divergence in G matrix structure has occurred mainly due to natural selection.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Digestive parameters and water turnover of the leopard tortoise.

    PubMed

    McMaster, Megan K; Downs, Colleen T

    2008-09-01

    Leopard tortoises (Stigmochelys pardalis) experience wide fluctuations in environmental conditions and unpredictable availability of food and water within the Nama-Karoo biome. It was hypothesised that tortoises fed two diets differing in preformed water and fibre content would have differing food intake, gut transit rate, assimilation efficiency, faecal and urinary water loss, and urine concentrations. It was predicted that tortoises fed these contrasting diets would attempt to maintain energy and water balance by altering their digestive parameters. Leopard tortoises fed lucerne (Medicago sativa) had a low food intake coupled with long gut transit times, which resulted in the lowest amount of faecal energy and faecal water lost. Tortoises fed tomatoes (Solanum lycopersicum) had higher food intake and faster gut transit times, but more energy and water was lost in the faeces. However, daily energy assimilated and assimilation efficiency were comparable between tortoises fed the two diets. Urine osmolality was significantly different between tortoises on the two diets. Results indicate that leopard tortoises can adjust parameters such as transit rate, food intake, water loss and urine osmolality to maintain body mass, water and energy balance in response to a high fibre, low water content and a low fibre, high water content diet. This study suggests that this digestive flexibility allows leopard tortoises in the wild to take advantage of unpredictable food and water resources.

  4. Face Value: Towards Robust Estimates of Snow Leopard Densities.

    PubMed

    Alexander, Justine S; Gopalaswamy, Arjun M; Shi, Kun; Riordan, Philip

    2015-01-01

    When densities of large carnivores fall below certain thresholds, dramatic ecological effects can follow, leading to oversimplified ecosystems. Understanding the population status of such species remains a major challenge as they occur in low densities and their ranges are wide. This paper describes the use of non-invasive data collection techniques combined with recent spatial capture-recapture methods to estimate the density of snow leopards Panthera uncia. It also investigates the influence of environmental and human activity indicators on their spatial distribution. A total of 60 camera traps were systematically set up during a three-month period over a 480 km2 study area in Qilianshan National Nature Reserve, Gansu Province, China. We recorded 76 separate snow leopard captures over 2,906 trap-days, representing an average capture success of 2.62 captures/100 trap-days. We identified a total number of 20 unique individuals from photographs and estimated snow leopard density at 3.31 (SE = 1.01) individuals per 100 km2. Results of our simulation exercise indicate that our estimates from the Spatial Capture Recapture models were not optimal to respect to bias and precision (RMSEs for density parameters less or equal to 0.87). Our results underline the critical challenge in achieving sufficient sample sizes of snow leopard captures and recaptures. Possible performance improvements are discussed, principally by optimising effective camera capture and photographic data quality.

  5. Face Value: Towards Robust Estimates of Snow Leopard Densities

    PubMed Central

    2015-01-01

    When densities of large carnivores fall below certain thresholds, dramatic ecological effects can follow, leading to oversimplified ecosystems. Understanding the population status of such species remains a major challenge as they occur in low densities and their ranges are wide. This paper describes the use of non-invasive data collection techniques combined with recent spatial capture-recapture methods to estimate the density of snow leopards Panthera uncia. It also investigates the influence of environmental and human activity indicators on their spatial distribution. A total of 60 camera traps were systematically set up during a three-month period over a 480 km2 study area in Qilianshan National Nature Reserve, Gansu Province, China. We recorded 76 separate snow leopard captures over 2,906 trap-days, representing an average capture success of 2.62 captures/100 trap-days. We identified a total number of 20 unique individuals from photographs and estimated snow leopard density at 3.31 (SE = 1.01) individuals per 100 km2. Results of our simulation exercise indicate that our estimates from the Spatial Capture Recapture models were not optimal to respect to bias and precision (RMSEs for density parameters less or equal to 0.87). Our results underline the critical challenge in achieving sufficient sample sizes of snow leopard captures and recaptures. Possible performance improvements are discussed, principally by optimising effective camera capture and photographic data quality. PMID:26322682

  6. The first taxonomic revaluation of the Iranian water frogs of the genus Pelophylax (Anura: Ranidae) using sequences of the mitochondrial genome.

    PubMed

    Pesarakloo, Alireza; Rastegar-Pouyani, Eskandar; Rastegar-Pouyani, Nasrollah; Kami, Hajigholi; Najibzadeh, Masoumeh; Khosravani, Azar; Oraie, Hamzeh

    2017-05-01

    The Eurasian water frog species and their geographic ranges have undergone considerable changes in the last four decades, but the Iranian populations have largely remained unknown. All the Iranian populations of water frogs, despite their vast distribution range have attributed to a single species: Rana ridibunda. In order to understand the phylogenetic relationships and taxonomic status of water frogs of Iran, we collected samples from many populations across the country and used the mitochondrial DNA sequence variation. A data set with a final sequence length of 616 nucleotides was generated for Cyt b from 70 individuals of Pelophylax in which there are 422 invariable sites, 174 variable sites of which 123 were parsimony informative. In total, 43 haplotypes were found (Hd: 0.9752). The result demonstrated that, two major clades with strong support can be identified within the Iranian water frogs. One of these clades that include north western and southwestern populations forms a monophyletic group along with P. bedriagae samples from Turkey. The second clade consists of water frog populations of north and northeastern parts of Iran which in turn is subdivided into two subclades. Inclusion of water frog samples from adjacent areas showed that the second clade of our study is, most likely, a distinct taxonomic entity at species rank with its two subclades indicating two diagnosable subspecies for the clade. In conclusion, we suggest that two distinct species, P. bedriagae and Pelophylax sp., with its two subspecies, should be identified as water frogs of Iran. In Addition, another traditionally reported water frog of Iran, P.ridibundus, most likely should be excluded from the Iranian water frog's checklist.

  7. Prey preferences of the snow leopard (Panthera uncia): regional diet specificity holds global significance for conservation.

    PubMed

    Lyngdoh, Salvador; Shrotriya, Shivam; Goyal, Surendra P; Clements, Hayley; Hayward, Matthew W; Habib, Bilal

    2014-01-01

    The endangered snow leopard is a large felid that is distributed over 1.83 million km(2) globally. Throughout its range it relies on a limited number of prey species in some of the most inhospitable landscapes on the planet where high rates of human persecution exist for both predator and prey. We reviewed 14 published and 11 unpublished studies pertaining to snow leopard diet throughout its range. We calculated prey consumption in terms of frequency of occurrence and biomass consumed based on 1696 analysed scats from throughout the snow leopard's range. Prey biomass consumed was calculated based on the Ackerman's linear correction factor. We identified four distinct physiographic and snow leopard prey type zones, using cluster analysis that had unique prey assemblages and had key prey characteristics which supported snow leopard occurrence there. Levin's index showed the snow leopard had a specialized dietary niche breadth. The main prey of the snow leopard were Siberian ibex (Capra sibrica), blue sheep (Pseudois nayaur), Himalayan tahr (Hemitragus jemlahicus), argali (Ovis ammon) and marmots (Marmota spp). The significantly preferred prey species of snow leopard weighed 55±5 kg, while the preferred prey weight range of snow leopard was 36-76 kg with a significant preference for Siberian ibex and blue sheep. Our meta-analysis identified critical dietary resources for snow leopards throughout their distribution and illustrates the importance of understanding regional variation in species ecology; particularly prey species that have global implications for conservation.

  8. Prey Preferences of the Snow Leopard (Panthera uncia): Regional Diet Specificity Holds Global Significance for Conservation

    PubMed Central

    Lyngdoh, Salvador; Shrotriya, Shivam; Goyal, Surendra P.; Clements, Hayley; Hayward, Matthew W.; Habib, Bilal

    2014-01-01

    The endangered snow leopard is a large felid that is distributed over 1.83 million km2 globally. Throughout its range it relies on a limited number of prey species in some of the most inhospitable landscapes on the planet where high rates of human persecution exist for both predator and prey. We reviewed 14 published and 11 unpublished studies pertaining to snow leopard diet throughout its range. We calculated prey consumption in terms of frequency of occurrence and biomass consumed based on 1696 analysed scats from throughout the snow leopard's range. Prey biomass consumed was calculated based on the Ackerman's linear correction factor. We identified four distinct physiographic and snow leopard prey type zones, using cluster analysis that had unique prey assemblages and had key prey characteristics which supported snow leopard occurrence there. Levin's index showed the snow leopard had a specialized dietary niche breadth. The main prey of the snow leopard were Siberian ibex (Capra sibrica), blue sheep (Pseudois nayaur), Himalayan tahr (Hemitragus jemlahicus), argali (Ovis ammon) and marmots (Marmota spp). The significantly preferred prey species of snow leopard weighed 55±5 kg, while the preferred prey weight range of snow leopard was 36–76 kg with a significant preference for Siberian ibex and blue sheep. Our meta-analysis identified critical dietary resources for snow leopards throughout their distribution and illustrates the importance of understanding regional variation in species ecology; particularly prey species that have global implications for conservation. PMID:24533080

  9. Teams Explore the Whole Frog

    ERIC Educational Resources Information Center

    Cessna, Clair E.

    1973-01-01

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

  10. Crucial role of cytoskeleton reorganization in the negative inotropic effect of chromogranin A-derived peptides in eel and frog hearts.

    PubMed

    Mazza, Rosa; Mannarino, Cinzia; Imbrogno, Sandra; Barbieri, Sandra Francesca; Adamo, Cristina; Angelone, Tommaso; Corti, Angelo; Tota, Bruno

    2007-02-01

    Vasostatins (VSs), i.e. the main biologically active peptides generated by the proteolytic processing of chromogranin A (CGA) N-terminus, exert negative inotropism in vertebrate hearts. Here, using isolated working eel (Anguilla anguilla) and frog (Rana esculenta) heart preparations, we have studied the role of the cytoskeleton in the VSs-mediated inotropic response. In both eel and frog hearts, VSs-mediated-negative inotropy was abolished by treatment with inhibitors of cytoskeleton reorganization, such as cytochalasin-D (eel: 10 nM; frog: 1 nM), an inhibitor of actin polymerisation, wortmannin (0.01 nM), an inhibitor of PI3-kinase (PI3-K)/protein kinase B (Akt) signal-transduction cascade, butanedione 2-monoxime (BDM) (eel: 100 nM; frog: 10 nM), an antagonist of myosin ATPase, and N-(6-aminohexil)-5-chloro-1-naphthalenesulfonamide (W7) (eel: 100 nM; frog: 1 nM), a calcium-calmodulin antagonist. These results demonstrate that changes in cytoskeletal dynamics play a crucial role in the negative inotropic influence of VSs on eel and frog hearts.

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

    PubMed Central

    Suter, Robert. B.

    2003-01-01

    Fishing spiders (Pisauridae) frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana) and green frogs (R. clamitans) on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances), rearing the legs nearest the attacking frog (N=15, 29.4%), or showing no visible response (N=7, 13.7%). Spiders that jumped always did so away (in the vertical plane) from the attack (mean =137° vs. vertical at 90° or horizontally toward the frog at 0°). The involvement of the trichobothria (leg hairs sensitive to air movements), and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack. Abbreviation: a acceleration (m s−2) fps frames per second HS high-speed video v velocity (m s−1) PMID:15841235

  12. Identification and characterization of major histocompatibility complex class IIB alleles from three species of European ranid frogs

    PubMed Central

    A. Marosi, Béla; M. Kiemnec-Tyburczy, Karen; V. Ghira, Ioan; Sos, Tibor; Popescu, Octavian

    2014-01-01

    Immune genes of the major histocompatibility complex (MHC) are among the most polymorphic genes in the vertebrate genome. Due to their polymorphic nature, they are often used to assess the adaptive genetic variability of natural populations. This study describes the first molecular characterization of 13 partial MHC class IIB sequences from three European ranid frogs. The utility of previously published primers was expanded by using them to successfully amplify eight exon 2 alleles from Rana arvalis.We also designed a novel primer set that successfully amplified exon 2 from Pelophylax kurtmuelleri. Pelophylax lessonae was also designed as part of this study. Results indicate the presence of one or two class IIB loci in these three species. In R. arvalis, significant evidence of positive selection acting on MHC antigen binding sites was found. Many European ranid populations are experiencing disease-related declines; the newly developed primers can, therefore, be used for further population analyses of native frogs. PMID:27843985

  13. Lithobates sylvaticus (wood frog)

    USGS Publications Warehouse

    Fuller, Pam

    2017-01-01

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

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

    PubMed

    Arkle, Robert S; Pilliod, David S

    2015-09-01

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

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

    USGS Publications Warehouse

    Arkle, Robert S.; Pilliod, David S.

    2015-01-01

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

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

    PubMed Central

    Arkle, Robert S; Pilliod, David S

    2015-01-01

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

  17. Prey capture in frogs: alternative strategies, biomechanical trade-offs, and hierarchical decision making.

    PubMed

    Monroy, Jenna A; Nishikawa, Kiisa

    2011-02-01

    Frogs exhibit flexible repertoires of prey-capture behavior, which depend primarily on visual analysis of prey attributes. We review three examples of how visual cues are used to modulate prey-capture strategies. (1) Dyscophus guineti modulates tongue aiming in response to prey location. These frogs turn only their heads to apprehend prey located at azimuths <40°. At azimuths >40°, the frogs switch from this strategy to one in which both head and tongue are aimed toward prey. (2) Rana pipiens modulates its feeding behavior in response to prey size, using tongue prehension for capturing small prey but switching to jaw prehension to capture large prey. (3) In Cyclorana novaehollandiae, visual processing of prey attributes involves hierarchical decision making. These frogs first assess prey size. For large prey, they ignore velocity but not shape. For small prey, they ignore shape but not velocity. Alternative prey-capture strategies are associated with biomechanical trade-offs that result from the interaction between the feeding apparatus and varying attributes of prey. Alternative strategies likely exist because biomechanical constraints prevent any one strategy from being effective over a range of prey attributes. Taken together, these studies emphasize the requirement that predators must somehow tune prey-capture kinematics simultaneously to multiple attributes of prey. In frogs, the choice among alternative prey-capture strategies involves a hierarchical decision-making process. Hierarchical decision making is expected to be widespread among animals. However, no previous studies were found except for humans, who frequently use this type of approach to make complex decisions.

  18. Calcium Sparks in Intact Skeletal Muscle Fibers of the Frog

    PubMed Central

    Hollingworth, S.; Peet, J.; Chandler, W.K; Baylor, S.M.

    2001-01-01

    Calcium sparks were studied in frog intact skeletal muscle fibers using a home-built confocal scanner whose point-spread function was estimated to be ∼0.21 μm in x and y and ∼0.51 μm in z. Observations were made at 17–20°C on fibers from Rana pipiens and Rana temporaria. Fibers were studied in two external solutions: normal Ringer's ([K+] = 2.5 mM; estimated membrane potential, −80 to −90 mV) and elevated [K+] Ringer's (most frequently, [K+] = 13 mM; estimated membrane potential, −60 to −65 mV). The frequency of sparks was 0.04–0.05 sarcomere−1 s−1 in normal Ringer's; the frequency increased approximately tenfold in 13 mM [K+] Ringer's. Spark properties in each solution were similar for the two species; they were also similar when scanned in the x and the y directions. From fits of standard functional forms to the temporal and spatial profiles of the sparks, the following mean values were estimated for the morphological parameters: rise time, ∼4 ms; peak amplitude, ∼1 ΔF/F (change in fluorescence divided by resting fluorescence); decay time constant, ∼5 ms; full duration at half maximum (FDHM), ∼6 ms; late offset, ∼0.01 ΔF/F; full width at half maximum (FWHM), ∼1.0 μm; mass (calculated as amplitude × 1.206 × FWHM3), 1.3–1.9 μm3. Although the rise time is similar to that measured previously in frog cut fibers (5–6 ms; 17–23°C), cut fiber sparks have a longer duration (FDHM, 9–15 ms), a wider extent (FWHM, 1.3–2.3 μm), and a strikingly larger mass (by 3–10-fold). Possible explanations for the increase in mass in cut fibers are a reduction in the Ca2+ buffering power of myoplasm in cut fibers and an increase in the flux of Ca2+ during release. PMID:11723160

  19. Molecular findings of disseminated histoplasmosis in two captive snow leopards (Uncia uncia).

    PubMed

    Espinosa-Avilés, David; Taylor, Maria Lucia; del Rocio Reyes-Montes, Maria; Pérez-Torrez, Armando

    2008-09-01

    This paper reports two cases of disseminated histoplasmosis in captive snow leopards (Uncia uncia). Histoplasmosis was diagnosed based on histopathology, immunohistochemistry, transmission electron microscopy, and molecular findings.

  20. Dual effect of GABA on descending monosynaptic excitatory postsynaptic potential in frog lumbar motoneurons.

    PubMed

    Ovsepian, S V; Vesselkin, N P

    2004-01-01

    Monosynaptic excitatory postsynaptic potentials (EPSPs) evoked by stimulating ipsilateral ventrolateral column (VLC) in the thoracic section were recorded in lumbar motoneurons within the isolated spinal cord of the frog Rana ridibunda. Bath application of the selective GABAB receptor agonist (-)-baclofen (0.05 mM) caused a reduction in the peak amplitude of VLC EPSP. Baclofen did not cause any consistent change in the membrane potential or in the EPSP waveform within frog motoneurones. The selective GABA(B) receptor antagonist saclofen (0.1 mM) completely blocked the effect of (-)-baclofen on VLC EPSP. A decrease in VLC EPSP peak amplitude was also observed during GABA (0.5 mM) application. Unlike (-)-baclofen, inhibition of VLC EPSP induced by GABA was accompanied by a shortening of the EPSP time course and a reduction in membrane input resistance within lumbar motoneurons. The decrease in VLC EPSP peak amplitude induced by (-)-baclofen and GABA was accompanied by an increase in the paired-pulse facilitation. These data provide evidence for a dual pre- and postsynaptic GABAergic inhibition of the VLC monosynaptic EPSP in lumbar motoneurons within the frog spinal cord.

  1. Novel control of lactate dehydrogenase from the freeze tolerant wood frog: role of posttranslational modifications

    PubMed Central

    Abboud, Jean

    2013-01-01

    Lactate dehydrogenase (LDH), the terminal enzyme of anaerobic glycolysis, plays a crucial role both in sustaining glycolytic ATP production under oxygen-limiting conditions and in facilitating the catabolism of accumulated lactate when stress conditions are relieved. In this study, the effects on LDH of in vivo freezing and dehydration stresses (both of which impose hypoxia/anoxia stress on tissues) were examined in skeletal muscle of the freeze-tolerant wood frog, Rana sylvatica. LDH from muscle of control, frozen and dehydrated wood frogs was purified to homogeneity in a two-step process. The kinetic properties and stability of purified LDH were analyzed, revealing no significant differences in Vmax, Km and I50 values between control and frozen LDH. However, control and dehydrated LDH differed significantly in Km values for pyruvate, lactate, and NAD, I50 urea, and in temperature, glucose, and urea effects on these parameters. The possibility that posttranslational modification of LDH was responsible for the stable differences in enzyme behavior between control and dehydrated states was assessed using ProQ diamond staining to detect phosphorylation and immunoblotting to detect acetylation, methylation, ubiquitination, SUMOylation and nitrosylation of the enzyme. LDH from muscle of dehydrated wood frogs showed significantly lower levels of acetylation, providing one of the first demonstrations of a potential role for protein acetylation in the stress-responsive control of a metabolic enzyme. PMID:23638346

  2. High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation

    USGS Publications Warehouse

    Funk, W.C.; Greene, A.E.; Corn, P.S.; Allendorf, F.W.

    2005-01-01

    Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture–recapture analysis of over 10 000 frogs in combination with genetic analysis of microsatellite loci in replicate basins. We found that frogs had exceptionally high juvenile dispersal rates (up to 62% annually) over long distances (>5 km), large elevation gains (>750 m) and steep inclines (36° incline over 2 km) that were corroborated by genetic data showing high gene flow. These findings show that dispersal is an important life-history feature of some amphibians and suggest that habitat fragmentation is a serious threat to amphibian persistence.

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

    PubMed Central

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

    2015-01-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines. PMID:25514536

  4. Novel control of lactate dehydrogenase from the freeze tolerant wood frog: role of posttranslational modifications.

    PubMed

    Abboud, Jean; Storey, Kenneth B

    2013-01-01

    Lactate dehydrogenase (LDH), the terminal enzyme of anaerobic glycolysis, plays a crucial role both in sustaining glycolytic ATP production under oxygen-limiting conditions and in facilitating the catabolism of accumulated lactate when stress conditions are relieved. In this study, the effects on LDH of in vivo freezing and dehydration stresses (both of which impose hypoxia/anoxia stress on tissues) were examined in skeletal muscle of the freeze-tolerant wood frog, Rana sylvatica. LDH from muscle of control, frozen and dehydrated wood frogs was purified to homogeneity in a two-step process. The kinetic properties and stability of purified LDH were analyzed, revealing no significant differences in V max, K m and I 50 values between control and frozen LDH. However, control and dehydrated LDH differed significantly in K m values for pyruvate, lactate, and NAD, I 50 urea, and in temperature, glucose, and urea effects on these parameters. The possibility that posttranslational modification of LDH was responsible for the stable differences in enzyme behavior between control and dehydrated states was assessed using ProQ diamond staining to detect phosphorylation and immunoblotting to detect acetylation, methylation, ubiquitination, SUMOylation and nitrosylation of the enzyme. LDH from muscle of dehydrated wood frogs showed significantly lower levels of acetylation, providing one of the first demonstrations of a potential role for protein acetylation in the stress-responsive control of a metabolic enzyme.

  5. High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation

    PubMed Central

    Funk, W. Chris; Greene, Allison E; Corn, Paul Stephen; Allendorf, Fred W

    2005-01-01

    Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disregarded as a cause of amphibian declines and conservation efforts can be focused elsewhere. We examined dispersal rates in Columbia spotted frogs (Rana luteiventris) using capture–recapture analysis of over 10 000 frogs in combination with genetic analysis of microsatellite loci in replicate basins. We found that frogs had exceptionally high juvenile dispersal rates (up to 62% annually) over long distances (>5 km), large elevation gains (>750 m) and steep inclines (36° incline over 2 km) that were corroborated by genetic data showing high gene flow. These findings show that dispersal is an important life-history feature of some amphibians and suggest that habitat fragmentation is a serious threat to amphibian persistence. PMID:17148116

  6. Peptides from the N-terminal domain of chromogranin A (vasostatins) exert negative inotropic effects in the isolated frog heart.

    PubMed

    Tota, Bruno; Mazza, Rosa; Angelone, Tommaso; Nullans, Gerard; Metz-Boutigue, Marie-Hélène; Aunis, Dominique; Helle, Karen B

    2003-07-15

    The negative inotropic effects of synthetic peptides derived from the N-terminus of chromogranin A (CgA) were studied in an avascular model of the vertebrate myocardium, the isolated working frog heart (Rana esculenta). The peptides were frog and bovine CgA(4-16) and CgA(47-66), and bovine CgA(1-40) with (CgA(1-40SS)) and without an intact disulfide bridge (CgA(1-40SH)). Under basal cardiac conditions, four of the peptides caused a concentration-dependent negative inotropism that was comparable to the negative inotropy reported for human recombinant vasostatin I (CgA(1-78)) and bovine CgA(7-57). By comparison of the structural characteristics of the bovine and frog sequences with their minimally effective concentrations ranging from 68 to 125 nM of peptide, the results were consistent with the natural structure (CgA(17-38SS)) being essential for the negative inotropism. In addition, the partial sequences of the frog and bovine vasostatin I were effective in counteracting the characteristic positive inotropism exerted by isoproterenol (1 nM) at minimally effective concentrations ranging from 45 to 272 nM. Taken together, these results extend the first evidence for a cardiosuppressive role of the N-terminal domain of chromogranin A known for its co-storage with catecholamines in the sympathoadrenal system of vertebrates.

  7. Cheetahs have a stronger constitutive innate immunity than leopards

    PubMed Central

    Heinrich, Sonja K.; Hofer, Heribert; Courtiol, Alexandre; Melzheimer, Jörg; Dehnhard, Martin; Czirják, Gábor Á.; Wachter, Bettina

    2017-01-01

    As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy. By comparing the functional competence of the humoral immune system of both species in sympatric populations in Namibia, we demonstrate that cheetahs have a higher constitutive innate but lower induced innate and adaptive immunity than leopards. We conclude (1) immunocompetence of cheetahs is higher than previously thought; (2) studying both innate and adaptive components of immune systems will enrich conservation science. PMID:28333126

  8. Benign gastric neuroendocrine tumors in three snow leopards (Panthera uncia).

    PubMed

    Dobson, Elizabeth C; Naydan, Dianne K; Raphael, Bonnie L; McAloose, Denise

    2013-06-01

    Neuroendocrine tumors are relatively rare neoplasms arising from neuroendocrine cells that are distributed throughout the body and are predominant in the gastrointestinal tract. This report describes benign, well-differentiated gastric neuroendocrine tumors in three captive snow leopards (Panthera uncia). All tumors were well circumscribed, were within the gastric mucosa or submucosa, and had histologic and immunohistochemical features of neuroendocrine tumors. Histologic features included packeted cuboidal to columnar epithelial cells that were arranged in palisades or pseudorosettes and contained finely granular cellular cytoplasm with centrally placed, round nuclei. Cytoplasmic granules of neoplastic cells strongly expressed chromogranin A, variably expressed neuron-specific enolase, and did not express synaptophysin or gastrin. Each leopard died or was euthanatized for reasons unrelated to its tumor.

  9. Cutaneous atypical mycobacteriosis in a clouded leopard (Neofelis nebulosa).

    PubMed

    Cerveny, Shannon N S; Thompson, Michelle E; Corner, Sarah M; Swinford, Amy K; Coke, Rob L

    2013-09-01

    A 16-yr-old male clouded leopard (Neofelis nebulosa) was presented for lethargy and anorexia. A cutaneous abdominal mass extending from the pubis to just caudal to the xiphoid process was present. A biopsy revealed histologic lesions consistent with an atypical mycobacterial infection consisting of diffuse, severe, pyogranulomatous dermatitis and panniculitis, with clear vacuoles and 3-5 microm, intravacuolar, faintly eosinophilic, filamentous bacilli that stained positively with FiteFaraco modified acid-fast stain. The clouded leopard had biochemical findings suggestive of chronic renal failure and euthanasia was elected. Histological evaluation of tissues collected at postmortem examination revealed multicentric B-cell lymphoma involving the oral cavity, liver, spleen, and multiple lymph nodes, bilateral testicular seminomas, thyroid follicular cell adenoma, thyroid C cell adenoma, and biliary cystadenomas. Bacterial culture and molecular sequencing identified the causative agent of the cutaneous abdominal mass as belonging to the Mycobacterium fortuitum group.

  10. Seminoma and parathyroid adenoma in a snow leopard (Panthera unica).

    PubMed

    Doster, A R; Armstrong, D L; Bargar, T W

    1989-05-01

    A seminoma and parathyroid adenoma were diagnosed in an aged snow leopard. The ultrastructural appearance of the seminoma was similar to that described in the dog and in man. The lack of significant amounts of rough endoplasmic reticulum, Golgi complexes and free ribosomes in the parathyroid adenoma suggested that it was non-functional. Parathyroid adenoma has not been previously described in a large wild feline.

  11. Multiscale factors affecting human attitudes toward snow leopards and wolves.

    PubMed

    Suryawanshi, Kulbhushansingh R; Bhatia, Saloni; Bhatnagar, Yash Veer; Redpath, Stephen; Mishra, Charudutt

    2014-12-01

    The threat posed by large carnivores to livestock and humans makes peaceful coexistence between them difficult. Effective implementation of conservation laws and policies depends on the attitudes of local residents toward the target species. There are many known correlates of human attitudes toward carnivores, but they have only been assessed at the scale of the individual. Because human societies are organized hierarchically, attitudes are presumably influenced by different factors at different scales of social organization, but this scale dependence has not been examined. We used structured interview surveys to quantitatively assess the attitudes of a Buddhist pastoral community toward snow leopards (Panthera uncia) and wolves (Canis lupus). We interviewed 381 individuals from 24 villages within 6 study sites across the high-elevation Spiti Valley in the Indian Trans-Himalaya. We gathered information on key explanatory variables that together captured variation in individual and village-level socioeconomic factors. We used hierarchical linear models to examine how the effect of these factors on human attitudes changed with the scale of analysis from the individual to the community. Factors significant at the individual level were gender, education, and age of the respondent (for wolves and snow leopards), number of income sources in the family (wolves), agricultural production, and large-bodied livestock holdings (snow leopards). At the community level, the significant factors included the number of smaller-bodied herded livestock killed by wolves and mean agricultural production (wolves) and village size and large livestock holdings (snow leopards). Our results show that scaling up from the individual to higher levels of social organization can highlight important factors that influence attitudes of people toward wildlife and toward formal conservation efforts in general. Such scale-specific information can help managers apply conservation measures at

  12. LEOPARD syndrome with partly normal skin and sex chromosome mosaicism.

    PubMed

    Writzl, Karin; Hoovers, Jan; Sistermans, Erik A; Hennekam, Raoul C M

    2007-11-01

    We report on a family with LEOPARD syndrome which was molecularly proven (p.Thr468Met in PTPN11) in a father and his adult son. The father had multiple lentigines dispersed equally over his body; the son was similarly affected except for the left part of thorax, back and left arm, which were completely devoid of lentigines and only showed a few nevi. In addition, the son was found to have a mosaic karyotype, 47,XYY/46,XY, in lymphocytes. Skin biopsies from the pigmented and unpigmented forearm showed that mainly a 47,XYY karyotype was present in the pigmented skin and mainly a 46,XY karyotype in the unpigmented skin. In both fibroblast cultures the PTPN11 mutation was present, and no additional mutation could be detected. We discuss the various possible explanations for this phenotype, which include the possibility of coincidence; revertant mosaicism; silencing of a second PTPN11 mutation; gene(s) located on a sex chromosome influencing the phenotype; and epigenetic influences. We favor that the co-occurrence of a sex chromosome mosaicism and mosaicism for skin symptoms in a single patient with LEOPARD syndrome is coincidence, but that mosaicism for LEOPARD skin symptoms in itself may well be more frequent and needs additional studies. Each of the above-hypothesized mechanisms may then remain possible.

  13. Comparative High-Density Linkage Mapping Reveals Conserved Genome Structure but Variation in Levels of Heterochiasmy and Location of Recombination Cold Spots in the Common Frog

    PubMed Central

    Palomar, Gemma; Ahmad, Freed; Vasemägi, Anti; Matsuba, Chikako; Nicieza, Alfredo G.; Cano, José Manuel

    2016-01-01

    By combining 7077 SNPs and 61 microsatellites, we present the first linkage map for some of the early diverged lineages of the common frog, Rana temporaria, and the densest linkage map to date for this species. We found high homology with the published linkage maps of the Eastern and Western lineages but with differences in the order of some markers. Homology was also strong with the genome of the Tibetan frog Nanorana parkeri and we found high synteny with the clawed frog Xenopus tropicalis. We confirmed marked heterochiasmy between sexes and detected nonrecombining regions in several groups of the male linkage map. Contrary to the expectations set by the male heterogamety of the common frog, we did not find male heterozygosity excess in the chromosome previously shown to be linked to sex determination. Finally, we found blocks of loci showing strong transmission ratio distortion. These distorted genomic regions might be related to genetic incompatibilities between the parental populations, and are promising candidates for further investigation into the genetic basis of speciation and adaptation in the common frog. PMID:28040782

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

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

    ERIC Educational Resources Information Center

    Crane, Lisa Marie

    1997-01-01

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

  16. LAPAROSCOPIC SALPINGECTOMY IN TWO CAPTIVE LEOPARDS (PANTHERA PARDUS) USING A SINGLE PORTAL ACCESS SYSTEM.

    PubMed

    Hartman, Marthinus J; Monnet, Eric; Kirberger, Robert M; Schoeman, Johan P

    2015-12-01

    Laparoscopic salpingectomy was performed in two adult leopards (Panthera pardus) using a single portal access system, with a multicannulated single-incision laparoscopic surgery port, without any complications. The poorly developed ovarian bursa provided easy access to the uterine tube for salpingectomy. Laparoscopic salpingectomy can be safely performed in the leopard using a single portal access system.

  17. Discordance between mitochondrial DNA genealogy and nuclear DNA genetic structure in the two morphotypes of Rana tagoi tagoi (Amphibia: Anura: Ranidae) in the Kinki Region, Japan.

    PubMed

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro

    2013-07-01

    Two morphotypes, with a large and small body size, of a brown frog Rana t. tagoi occur sympatrically in the Kinki region, central Honshu of Japan. Previous mitochondrial (mt) DNA genealogical study recognized two main lineages (A and B) and several sublineages in R. tagoi, where the small type was placed in the group A-1b, and the large type in groups A-1a and B-2a. Using haplotype network and structure analysis of three nuclear genes, we examined the discrepancy between morphology and mitochondrial genealogy. The results showed that the small type is reproductively isolated from its co-occurring large type (A-1a or B-2a), and that unlimited gene flow occurred between parapatrically occurring two mtDNA lineages of large types (A-1a and B-2a). Discordant genetic relationships between mtDNA and nuclear DNA results may be caused by the past mitochondrial introgression, and possibly, the incomplete lineage sorting. These results also suggest a heterospecific relationship between the large (A-1a and B-2a) and small types (A-1b). The large type is identified as Rana t. tagoi as it is genetically very close to the topotypes of the nominal subspecies, while the small type remains unnamed.

  18. Frog virus 3-like infections in aquatic amphibian communities.

    PubMed

    Duffus, A L J; Pauli, B D; Wozney, K; Brunetti, C R; Berrill, M

    2008-01-01

    Frog virus 3 (FV3) and FV3-like viruses, are members of the genus Ranavirus (family Iridoviridae), and they have been associated with infectious diseases that may be contributing to amphibian population declines. We examined the mode of transmission of an FV3-like virus, and potential hosts and reservoirs of the virus in a local amphibian community. Using the polymerase chain reaction to detect infected animals, we found an FV3-like virus in south-central Ontario, Canada, amphibian communities, where it infects sympatric amphibian species, including ranid and hylid tadpoles (Rana sylvatica, Hyla versicolor, and Pseudacris spp.), larval salamanders (Ambystoma spp.), and adult eastern-spotted newts (Notophthalmus viridescens). The high prevalence of FV3-like infections in caudate larvae suggests that salamanders are likely to be both hosts and reservoirs. In laboratory FV3 challenges of R. sylvatica, the rate of infection was dependent on the amount of virus to which the animals were exposed. In addition, although vertical transmission was suspected, horizontal transmission through exposure to infected pond water is the most likely route of infection in tadpoles. Based on our observations, a simple model of FV3/FV3-like virus transmission postulates that, in aquatic amphibian communities, transmission of the virus occurs between anuran and urodele species, with ambystomatid salamanders the most likely reservoir for the ranavirus in our study.

  19. A serine proteinase inhibitor from frog eggs with bacteriostatic activity.

    PubMed

    Han, Yaoping; Yu, Haining; Yang, Xinbo; Rees, Huw H; Liu, Jingze; Lai, Ren

    2008-01-01

    By Sephadex G-50 gel filtration, Resource Q anionic exchange and C4 reversed phase liquid high performance liquid chromatography, a proteinase inhibitor protein (Ranaserpin) was identified and purified from the eggs of the odour frog, Rana grahami. The protein displayed a single band adjacent to the molecular weight marker of 14.4 kDa analyzed by SDS-PAGE. The inhibitor protein homogeneity and its molecular weight were confirmed again by MALDI-TOF mass spectrometry analysis. The MALDI-TOF mass spectrum analysis gave this inhibitor protein an m/z of 14422.26 that was matched well with the result from SDS-PAGE. This protein is a serine proteinase inhibitor targeting multiple proteinases including trypsin, elastase, and subtilisin. Ranaserpin inhibited the proteolytic activities of trypsin, elastase, and subtilisin. It has an inhibitory constant (K(i)) of 6.2 x 10(-8) M, 2.7 x 10(-7) M and 2.2 x 10(-8) M for trypsin, elastase, and subtilisin, respectively. This serine proteinase inhibitor exhibited bacteriostatic effect on Gram-positive bacteria Bacillus subtilis (ATCC 6633). It was suggested that ranaserpin might act as a defensive role in resistance to invasion of pests or pathogens. This is the first report of serine proteinase inhibitor and its direct defensive role from amphibian eggs.

  20. Regeneration of frog twitch and slow muscle fibers after mincing.

    PubMed

    Schmidt, H; Emser, W

    1985-10-01

    Iliofibularis muscles of Rana temporaria were minced and allowed to regenerate in the iliofibularis or the sartorius bed of the same frog. Regenerated muscles were examined for the presence of slow muscle fibers using electrophysiologic, histochemical, and contractile parameters. Muscle regeneration from sartorius mince was also studied. Regeneration was more successful from iliofibularis than from sartorius mince, and the iliofibularis bed was more favorable for regeneration than the sartorius bed for both types of muscle. Twitch fibers regenerated within a few months, but slow fibers could not be identified earlier than 14 months after muscle destruction. Slow muscle fibers regenerated only from iliofibularis mince, both orthotopically and heterotopically. All regenerates capable of maintaining a K-contracture contained histochemically identified slow fibers; the membrane properties of electrophysiologically identified slow fibers were normal. It is concluded that slow muscle fibers regenerate only from the remnants of a muscle that contains slow fibers. The results are discussed with respect to the role of innervating nerve fibers.

  1. Vasostatins exert negative inotropism in the working heart of the frog.

    PubMed

    Corti, A; Mannarino, C; Mazza, R; Colombo, B; Longhi, R; Tota, B

    2002-10-01

    An in vitro isolated working frog heart (Rana esculenta) was used to study the effects of exogenous CGA(1-76) (vasostatin 1), CGA(1-113) (vasostatin 2), and the synthetic CGA(7-57) on cardiac performance. Under basal cardiac conditions, the dose-response curves of the three peptides from 10(-8) to 10(-7) M showed a significant calcium-dependent negative inotropism that involved neither the endocardial endothelium nor the adrenergic and muscarinic receptors. In addition, the CgA fragments clearly counteracted the typical positive inotropism of isoprenaline (10(-<9) M). Taken together, these results provide the first evidence for a cardio-suppressive role for the vasostatins.

  2. Possible Role of Fish and Frogs as Paratenic Hosts of Dracunculus medinensis, Chad.

    PubMed

    Eberhard, Mark L; Yabsley, Michael J; Zirimwabagabo, Hubert; Bishop, Henry; Cleveland, Christopher A; Maerz, John C; Bringolf, Robert; Ruiz-Tiben, Ernesto

    2016-08-01

    Copepods infected with Dracunculus medinensis larvae collected from infected dogs in Chad were fed to 2 species of fish and tadpoles. Although they readily ingested copepods, neither species of fish, Nile tilapia (Oreochromis niloticus) nor fathead minnow (Pimephalis promelas), were found to harbor Dracunculus larvae when examined 2-3 weeks later. Tadpoles ingested copepods much more slowly; however, upon examination at the same time interval, tadpoles of green frogs (Lithobates [Rana] clamitans) were found to harbor small numbers of Dracunculus larvae. Two ferrets (Mustela putorius furo) were fed fish or tadpoles that had been exposed to infected copepods. Only the ferret fed tadpoles harbored developing Dracunculus larvae at necropsy 70-80 days postexposure. These observations confirm that D. medinensis, like other species in the genus Dracunculus, can readily survive and remain infective in potential paratenic hosts, especially tadpoles.

  3. The process for the activation of frog epidermis pro-tyrosinase.

    PubMed Central

    Peñafiel, R; Galindo, J D; Pedreño, E; Lozano, J A

    1982-01-01

    1. Purified pro-tyrosinase from epidermis of the frog Rana esculenta ridibunda can be activated in vitro by several proteinases (trypsin, alpha-chymotrypsin, Pronase) and by light. 2. Both pro-tyrosinase and tyrosinase are composed of a single type of subunit having pI 7.2 and approximate molecular weights 68000 and 62000 respectively. A peptide of low molecular weight is released as a consequence of the proteolytic activation. Pro-tyrosinase and tyrosinase have different quaternary structures, the proenzyme being a dimer of Mr approx. 115000 and the enzyme a tetramer of Mr approx. 210 000. 3. The activation process was affected by several agents (L-3,4-dihydroxyphenylalanine, urea, formamide) that prevented, partially or totally, the activation of pro-tyrosinase. 4. The activation of pro-tyrosinase seems to be the result of a cleavage of the polypeptide chain that determines changes in tertiary or quaternary structure. PMID:6814426

  4. Appearance of adenosine triphosphate in the perfusate from working frog heart.

    PubMed

    Doyle, T B; Forrester, T

    1985-09-01

    Frog hearts (Rana pipiens) were perfused in situ with Ringer's solution and the perfusate tested on firefly extract for the presence of ATP. At a normal perfusion pressure of 8 cm. H2O the rate of release of ATP into the perfusate was 8.8 (+/- S.E.1.7) pmoles.min-1. When the workload was increased by raising the perfusion pressure to 12 cm. H2O the rate of release increased to 28.3 (+/- S.E.4.8) pmoles.min-1. The rate of release was found to be proportional to the amount of workload imposed upon the heart. It is postulated that the trigger for release is hypoxia and that the release of ATP from the cardiac cell will augment contractility of the myocardium through its action upon adjacent cells via the P2 purinergic receptor. cells via the P2 purinergic receptor.

  5. Possible Role of Fish and Frogs as Paratenic Hosts of Dracunculus medinensis, Chad

    PubMed Central

    Yabsley, Michael J.; Zirimwabagabo, Hubert; Bishop, Henry; Cleveland, Christopher A.; Maerz, John C.; Bringolf, Robert; Ruiz-Tiben, Ernesto

    2016-01-01

    Copepods infected with Dracunculus medinensis larvae collected from infected dogs in Chad were fed to 2 species of fish and tadpoles. Although they readily ingested copepods, neither species of fish, Nile tilapia (Oreochromis niloticus) nor fathead minnow (Pimephalis promelas), were found to harbor Dracunculus larvae when examined 2–3 weeks later. Tadpoles ingested copepods much more slowly; however, upon examination at the same time interval, tadpoles of green frogs (Lithobates [Rana] clamitans) were found to harbor small numbers of Dracunculus larvae. Two ferrets (Mustela putorius furo) were fed fish or tadpoles that had been exposed to infected copepods. Only the ferret fed tadpoles harbored developing Dracunculus larvae at necropsy 70–80 days postexposure. These observations confirm that D. medinensis, like other species in the genus Dracunculus, can readily survive and remain infective in potential paratenic hosts, especially tadpoles. PMID:27434418

  6. Phylogenetic relationships of Oriental torrent frogs in the genus Amolops and its allies (Amphibia, Anura, Ranidae).

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Liu, Wan-Zhao; Maryati, Mohamed; Khonsue, Wichase; Orlov, Nikolai

    2006-03-01

    We investigated the phylogenetic relationships among 20 species of Oriental torrent frogs in the genus Amolops and its allies from China and Southeast Asia based on 1346-bp sequences of the mitochondrial 12S and 16S rRNA genes. Oriental species of the tribe Ranini form a monophyletic group containing 11 clades (Rana temporaria + Pseudoamolops, R. chalconota, four clades of Amolops, Meristogenys, three clades of Huia species, and Staurois) for which the phylogenetic relationships are unresolved. The genus Amolops consists of southern Chinese, southwestern Chinese, Thai, and Vietnamese-Malaysian lineages, but their relationships are also unresolved. The separation of southern and southwestern lineages within China conforms to previous morphological and karyological results. Species of Huia do not form a monophyletic group, whereas those of Meristogenys are monophyletic. Because P. sauteri is a sister species of R. temporaria, distinct generic status of Pseudoamolops is unwarranted.

  7. LEOPARD syndrome is not linked to the Marfan syndrome and the Watson syndrome loci

    SciTech Connect

    Rass-Rothchild, A.: Abeliovitch, D.; Kornstein, A. |

    1994-09-01

    The acronym LEOPARD stands for a syndromic association of Lentigines, Eletrocardiographic changes, Ocular hypertelorism, Pulmonic stenosis, Abnormal genitalia, Retardation of growth and sensorineural Deafness. Inheritance is autosomal dominant with high penetrance and variable expressivity. In 1990 Torok et al. reported on the association of LEOPARD and Marfan syndrome. In addition a clinical similarity (cardiac and cutaneous involvement) exists with the Watson syndrome (neurofibromatosis and pulmonic stenosis) which is linked to the marker D17S33 on chromosome 17. We studied possible linkage of LEOPARD syndrome to the Marfan syndrome locus on chromosome 15 (D15S1, MF13, and (TAAAA)n repeats) and to the NF-1 locus on chromosome 17 in a family with 9 cases of LEOPARD syndrome. Close linkage between LEOPARD syndrome and both the Marfan locus on chromosome 15 and the NF-1 locus on chromosome 17 was excluded (lod score <-2.0 through {theta} = 0.1).

  8. Bone Accumulation by Leopards in the Late Pleistocene in the Moncayo Massif (Zaragoza, NE Spain)

    PubMed Central

    Sauqué, Víctor; Rabal-Garcés, Raquel; Sola-Almagro, Cristina; Cuenca-Bescós, Gloria

    2014-01-01

    Eating habits of Panthera pardus are well known. When there are caves in its territory, prey accumulates inside them. This helps to prevent its kill from being stolen by other predators like hyenas. Although the leopard is an accumulator of bones in caves, few studies have been conducted on existing lairs. There are, however, examples of fossil vertebrate sites whose main collecting agent is the leopard. During the Late Pleistocene, the leopard was a common carnivore in European faunal associations. Here we present a new locality of Quaternary mammals with a scarce human presence, the cave of Los Rincones (province of Zaragoza, Spain); we show the leopard to be the main accumulator of the bones in the cave, while there are no interactions between humans and leopards. For this purpose, a taphonomic analysis is performed on different bone-layers of the cave. PMID:24642667

  9. Bone accumulation by leopards in the Late Pleistocene in the Moncayo massif (Zaragoza, NE Spain).

    PubMed

    Sauqué, Víctor; Rabal-Garcés, Raquel; Sola-Almagro, Cristina; Cuenca-Bescós, Gloria

    2014-01-01

    Eating habits of Panthera pardus are well known. When there are caves in its territory, prey accumulates inside them. This helps to prevent its kill from being stolen by other predators like hyenas. Although the leopard is an accumulator of bones in caves, few studies have been conducted on existing lairs. There are, however, examples of fossil vertebrate sites whose main collecting agent is the leopard. During the Late Pleistocene, the leopard was a common carnivore in European faunal associations. Here we present a new locality of Quaternary mammals with a scarce human presence, the cave of Los Rincones (province of Zaragoza, Spain); we show the leopard to be the main accumulator of the bones in the cave, while there are no interactions between humans and leopards. For this purpose, a taphonomic analysis is performed on different bone-layers of the cave.

  10. Effects of garlic (Allium sativum) extract on the heart rate, rhythm and force of contraction in frog: a dose-dependent study.

    PubMed

    Yadav, Raj Kumar; Verma, Nar Singh

    2004-06-01

    Garlic juice (dose equivalent to 3.3 g to 33 g garlic) mainly caused bradycardia in frog Rana tigerina. The disturbance in ventricular rhythm was observed prior to than that of atria. Rhythm was specially disturbed at higher doses causing bizarre pattern. Force of contraction of the heart also decreased with higher dose of the garlic extract. The results suggest that garlic extract has some beneficial effect on heart rate modulating the rate, rhythm and force of contraction positively but very high doses may exert non-desirable effects as well.

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

    PubMed

    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

  12. Carryover aquatic effects on survival of metamorphic frogs during pond emigration

    USGS Publications Warehouse

    Chelgren, N.D.; Rosenberg, D.K.; Heppell, S.S.; Gitelman, A.I.

    2006-01-01

    In organisms with complex life cycles, physiological stressors during early life stages may have fitness-level impacts that are delayed into later stages or habitats. We tested the hypothesis that body size and date of metamorphosis, which are highly responsive to aquatic stressors, influence post-metamorphic survival and movement patterns in the terrestrial phase of an ephemeral pond-breeding frog by examining these traits in two populations of northern red-legged frogs (Rana aurora aurora). To increase variation of body size at metamorphosis, we manipulated food availability for 314 of 1045 uniquely marked tadpoles and estimated the probability that frogs survived and emigrated using concentric rings of drift fencing surrounding ponds and Bayesian capture-recapture modeling. The odds of surviving and emigrating from the ponds to the innermost drift fences, ???12 m, increased by factors of 2.20 (95% credibility intervals 1.39-4.23) and 2.54 (0.94-4.91) with each millimeter increase in snout-vent length and decreased by factors of 0.91 (0.85-0.96) and 0.89 (0.80-1.00) with each day's delay in metamorphosis for the two ponds. The odds of surviving and moving to the next ring of fencing, 12 m to ???40 m from the ponds, increased by a factor of 1.20 (0.45-4.06) with each millimeter increase in size. Our results demonstrated that body size and timing of metamorphosis relate strongly to the performance of newly metamorphosed frogs during their initial transition into terrestrial habitat. Carryover effects of aquatic stressors that reduce size and delay metamorphosis may have population-level impacts that are not expressed until terrestrial stages. Since changes in both aquatic and terrestrial systems are implicated in many amphibian declines, quantifying both immediate and delayed effects of stressors on demographic rates is critical to sound management. ?? 2006 by the Ecological Society of America.

  13. Carryover aquatic effects on survival of metamorphic frogs during pond emigration.

    PubMed

    Chelgren, Nathan D; Rosenberg, Daniel K; Heppell, Selina S; Gitelman, Alix I

    2006-02-01

    In organisms with complex life cycles, physiological stressors during early life stages may have fitness-level impacts that are delayed into later stages or habitats. We tested the hypothesis that body size and date of metamorphosis, which are highly responsive to aquatic stressors, influence post-metamorphic survival and movement patterns in the terrestrial phase of an ephemeral pond-breeding frog by examining these traits in two populations of northern red-legged frogs (Rana aurora aurora). To increase variation of body size at metamorphosis, we manipulated food availability for 314 of 1045 uniquely marked tadpoles and estimated the probability that frogs survived and emigrated using concentric rings of drift fencing surrounding ponds and Bayesian capture-recapture modeling. The odds of surviving and emigrating from the ponds to the innermost drift fences, approximately 12 m, increased by factors of 2.20 (95% credibility intervals 1.39-4.23) and 2.54 (0.94-4.91) with each millimeter increase in snout-vent length and decreased by factors of 0.91 (0.85-0.96) and 0.89 (0.80-1.00) with each day's delay in metamorphosis for the two ponds. The odds of surviving and moving to the next ring of fencing, 12 m to approximately 40 m from the ponds, increased by a factor of 1.20 (0.45-4.06) with each millimeter increase in size. Our results demonstrated that body size and timing of metamorphosis relate strongly to the performance of newly metamorphosed frogs during their initial transition into terrestrial habitat. Carryover effects of aquatic stressors that reduce size and delay metamorphosis may have population-level impacts that are not expressed until terrestrial stages. Since changes in both aquatic and terrestrial systems are implicated in many amphibian declines, quantifying both immediate and delayed effects of stressors on demographic rates is critical to sound management.

  14. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  15. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  16. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  17. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  18. 49 CFR 213.137 - Frogs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  19. Hormonal induction of spermatozoa from amphibians with Rana temporaria and Bufo bufo as anuran models.

    PubMed

    Uteshev, V K; Shishova, N V; Kaurova, S A; Browne, R K; Gakhova, E N

    2012-01-01

    The use of hormonally induced spermatozoa expressed in urine (HISu) is a valuable component of reproduction technologies for amphibians. Five protocols for sampling HISu from the European common frog (Rana temporaria) were compared: (1) pituitary extracts, (2) 0.12 µg g⁻¹ luteinising hormone-releasing hormone analogue (LHRHa), (3) 1.20 µg g⁻¹ LHRHa, (4) 11.7 IU g⁻¹ human chorionic gonadotrophin (hCG) and (5) 23.4 IU g⁻¹ hCG (g⁻¹ = per gram bodyweight). From 1 to 24h after administration we assessed the number and concentration of spermatozoa in spermic urine and in holding water, and in urine the percentage of motile spermatozoa and their progressive motility. The protocol using 1.20 µg g⁻¹ LHRHa gave the highest total sperm numbers (650 × 10⁶) and the highest percentage (40%) of samples with sperm concentrations above 200 × 10⁶ mL⁻¹. The percentage motility and progressive motility was similar from all protocols. Considerable amounts of spermatozoa were expressed by R. temporaria into their holding water. We tested hormonal priming and spermiation in the common toad (Bufo bufo) using 0.13 µg g⁻¹ LHRHa administered 24h before a final spermiating dose of 12.8 IU g⁻¹ hCG. No spermatozoa were expressed in holding water. Priming resulted in 35% more spermatozoa than without; however, there were no differences in sperm concentrations. Primed B. bufo produced spermatozoa with significantly higher percentage motility, but not progressive motility, membrane integrity, or abnormal spermatozoa than unprimed males.

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

    USGS Publications Warehouse

    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.

  1. [Effects of cadmium on metamorphism and gonad differentiation in Rana chensinensis].

    PubMed

    Huang, Min-Yi; Wang, Hong-Yuan; Zhang, Yu-Hui

    2010-06-01

    200 tadpoles of Rana chensinensis at stage 26 - 27 were exposed to 0.05, 0.1, 0.2 or 0.4 mg/L Cd2+ in tap water respectively until they're fully metamorphic after which the heteromorphic young frogs in different treatments were anatomized, females and males were identified through gonad observation, and the female ratio was calculated. Localization of estrogen receptors (ER) in liver cells was investigated in different treatments using immunocytochemistry. The results showed that Cd2+ might induce limb abnormality, however, there was little correlation between abnormality rate and cadmium concentration in lower Cd2+ levels except for a higher limb abnormality ratio in the 0.4 mg/L group. On the other hand, Cd2+ could affect gonad differentiation. Compared to the control group, the proportion of female population increased in the 0.05 mg/L group and decreased in the 0.1, 0.2 and 0.4 mg/L ones. The sex rate in the 0.2 mg/L group is significantly different from that in the control group. Hermaphrodite gonads appeared in the two treatments with 0.2 mg/L and 0.4 mg/L of Cd2+. Additionally, ER expression was positive in both cytoplasm and nucleolus of liver cells in Cd2+ treated groups. But, there was no linear relationship between ER expressions levels and the concentration of Cd2+. These results suggested that cadmium can influence tadpole metamorphosis and gonad development by affecting the secretion of sex hormone.

  2. Unusually high predation on chacma baboons (Papio ursinus) by female leopards (Panthera pardus) in the Waterberg Mountains, South Africa.

    PubMed

    Jooste, E; Pitman, R T; van Hoven, W; Swanepoel, L H

    2012-01-01

    Leopards do not preferentially favour baboons as prey, but they are considered the primary predators of baboons across Africa. Even in areas where baboons are abundant, their contribution to leopard diet seldom exceeds 5% of biomass. It is suggested that the extreme aggressiveness of baboons, group vigilance and their high mobility when escaping may limit leopard predation. Male baboons are particularly aggressive, and retaliation often leads to the death of the leopard. However, evidence suggests that leopards may learn to catch and kill certain dangerous prey. This study reports predation on chacma baboons by 3 female leopards on a private game reserve in the Waterberg Mountains of South Africa. Potential leopard feeding sites were identified using global positioning system (GPS) location clusters obtained from GPS collars. Over a 5-month period, we investigated 200 potential leopard feeding sites and located 96 leopard feeding/kill sites. Baboons constituted 18.7% of the leopards' biomass intake. The majority of baboons preyed upon were adults and 70% of the kills were diurnal. In terms of the measured variables, there were no significant differences in the way the leopards preyed upon baboons, compared to the rest of the prey species.

  3. Behavioural adaptations of Rana temporaria to cold climates.

    PubMed

    Ludwig, Gerda; Sinsch, Ulrich; Pelster, Bernd

    2015-01-01

    Environmental conditions at the edge of a species' ecological optimum can exert great ecological or evolutionary pressure at local populations. For ectotherms like amphibians temperature is one of the most important abiotic factors of their environment as it influences directly their metabolism and sets limits to their distribution. Amphibians have evolved three ways to cope with sub-zero temperatures: freeze tolerance, freeze protection, freeze avoidance. The aim of this study was to assess which strategy common frogs at mid and high elevation use to survive and thrive in cold climates. In particular we (1) tested for the presence of physiological freeze protection, (2) evaluated autumnal activity and overwintering behaviour with respect to freeze avoidance and (3) assessed the importance of different high-elevation microhabitats for behavioural thermoregulation. Common frogs did not exhibit any signs of freeze protection when experiencing temperatures around 0 °C. Instead they retreated to open water for protection and overwintering. High elevation common frogs remained active for around the same period of time than their conspecifics at lower elevation. Our results suggest that at mid and high elevation common frogs use freeze avoidance alone to survive temperatures below 0 °C. The availability of warm microhabitats, such as rock or pasture, provides high elevation frogs with the opportunity of behavioural thermoregulation and thus allows them to remain active at temperatures at which common frogs at lower elevation cease activity.

  4. Cryptosporidium varanii infection in leopard geckos (Eublepharis macularius) in Argentina.

    PubMed

    Dellarupe, A; Unzaga, J M; Moré, G; Kienast, M; Larsen, A; Stiebel, C; Rambeaud, M; Venturini, M C

    2016-01-01

    Cryptosporidiosis is observed in reptiles with high morbidity and considerable mortality. The objective of this study was to achieve the molecular identification of Cryptosporidium spp. in pet leopard geckos (Eublepharis macularius) from a breeder colony in Buenos Aires, Argentina. Oocysts comparable to those of Cryptosporidium spp. were detected in three geckos with a history of diarrhea, anorexia and cachexia. Molecular identification methods confirmed the presence of Cryptosporidium varanii (syn. C. saurophilum). This agent was considered to be the primary cause of the observed clinical disease. This is the first description of C. varanii infection in pet reptiles in Argentina.

  5. Cryptosporidium varanii infection in leopard geckos (Eublepharis macularius) in Argentina

    PubMed Central

    Dellarupe, A.; Unzaga, J.M.; Moré, G.; Kienast, M.; Larsen, A.; Stiebel, C.; Rambeaud, M.; Venturini, M.C.

    2016-01-01

    Cryptosporidiosis is observed in reptiles with high morbidity and considerable mortality. The objective of this study was to achieve the molecular identification of Cryptosporidium spp. in pet leopard geckos (Eublepharis macularius) from a breeder colony in Buenos Aires, Argentina. Oocysts comparable to those of Cryptosporidium spp. were detected in three geckos with a history of diarrhea, anorexia and cachexia. Molecular identification methods confirmed the presence of Cryptosporidium varanii (syn. C. saurophilum). This agent was considered to be the primary cause of the observed clinical disease. This is the first description of C. varanii infection in pet reptiles in Argentina. PMID:27419102

  6. FROG: Time-series analysis

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair

    2014-06-01

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

  7. [Chromogranin A: immunocytochemical localization in secretory granules of frog atrial cardiomyocytes].

    PubMed

    Krylova, M I

    2007-01-01

    Chromogranin A (CgA) is a member of the granin family of acidic proteins that present in the secretory granules (SGs) of many endocrine, neuroendocrine and neuronal cells. Atrial natriuretic peptide (ANP)-storing SGs in atrial cardiomyocytes of rat heart also contain CgA. Cardiosuppressive effect of CgA-derived peptides (vasostatins) on in vitro isolated and perfused working frog and rat hearts has been shown under both basal conditions and beta-adrenergic stimulation. More recently it has been revealed that rat heart produces and processes CgA-derived vasostatin-containing peptides. Until now nothing has been known about the presence of CgA in an amphibian heart. We have investigated the subcellular localization of CgA in atrial myocytes of adult frog Rana temporaria heart using ultraimmunocytochemical method. Immunocytochemical staining of the frog atrial tissue for CgA and ANP has shown that out of three morphologically different types (A, B and D) of specific cytoplasmic granules (SCGs) present in myocytes only two (A and B)--large (120-200 nm in diameter) granules with more and with less electron dense core--exhibit immunoreactivity (IR) to these two antigens. The third type (D) of granules (80-100 nm in diameter) are small membrane bound granules characterized by highly electron dense core surrounded with a thin halo. These granules revealed negative reaction on immunostaining for both CgA and ANP. The presence of CgA- and ANP-IR in the same SCGs in frog atrial myocytes is consistent with the endocrine nature of these granules. Taking into account our and literature data we propose that CgA present in frog atrial cardiomyocite SCGs might be a precursor of vasostatin-containing peptides, as it takes place in rat heart. It is possible that these CgA-derived peptides together with ANP exert their regulatory function through the autocrine and/or paracrine mechanisms and play important cardioprotective role in frog heart under stress condition.

  8. Veno-occlusive disease in snow leopards (Panthera uncia) from zoological parks.

    PubMed

    Munson, L; Worley, M B

    1991-01-01

    Livers from 54 snow leopards, 4 days to 23 years old, that had died in 23 US zoos, were evaluated histopathologically to determine if the hepatic fibrosis, which has been noted to be prevalent in this species, was due to chronic active hepatitis from hepadnaviral infection, Ito cell proliferation, or hemosiderosis. Forty-two of 54 snow leopards had subintimal vascular fibrosis with partial or total occlusion of central and sublobular veins (veno-occlusive disease) of unknown origin. All 21 leopards older than 5 years were affected. Four leopards had chronic active hepatitis, and 12 leopards had cholangiohepatitis; but these lesions were not connected anatomically to central and sublobular venous fibrosis. Hepatocellular and Kupffer cell siderosis and Ito cell proliferation were prevalent and often coexisted with perisinusoidal, central, and sublobular venous fibrosis; but fibrosis was present in leopards without siderosis or Ito cell proliferation. The pattern and prevalence of veno-occlusive disease in these leopards was similar to that reported in captive cheetah (Acinonyx jubatus), suggesting that a common extrinsic factor may cause the majority of hepatic disease in these large felid animals in captivity.

  9. Modeling outcomes of approaches to sustained human and snow leopard coexistence.

    PubMed

    Wilman, Elizabeth A; Wilman, Elspeth N

    2016-02-01

    The snow leopard (Uncia uncia) is in danger of extinction. Killing to protect livestock is among the primary causes of its decline. Efforts to mitigate this threat have focused on balancing the need to conserve the snow leopard with the needs of local people in snow leopard habitat, many of whom rely on raising livestock for their livelihoods. Conservation of the snow leopard has the characteristics of a public good, and outside funding is required to support conservation efforts. There are 5 commonly discussed approaches to resolving this issue: (1) direct payments for conservation, (2) investments in protection from predation, (3) damage compensation payments, (4) investments in better livestock husbandry, and (5) leases of pastureland for wild prey. After a review of these 5 conservation strategies, an economic-ecologic model, which includes the interactions between the snow leopard, its wild prey, and livestock, is used to evaluate the 2 most promising conservation strategies. The model reveals that investments in protection from predation and leases of pastureland for wild prey are effective but only in delaying the eventual extinction of the snow leopard. To preserve the snow leopard, these approaches must be applied more aggressively and new ones explored.

  10. Snow Leopard and Himalayan Wolf: Food Habits and Prey Selection in the Central Himalayas, Nepal

    PubMed Central

    Odden, Morten; Wegge, Per

    2017-01-01

    Top carnivores play an important role in maintaining energy flow and functioning of the ecosystem, and a clear understanding of their diets and foraging strategies is essential for developing effective conservation strategies. In this paper, we compared diets and prey selection of snow leopards and wolves based on analyses of genotyped scats (snow leopards n = 182, wolves n = 57), collected within 26 sampling grid cells (5×5 km) that were distributed across a vast landscape of ca 5000 km2 in the Central Himalayas, Nepal. Within the grid cells, we sampled prey abundances using the double observer method. We found that interspecific differences in diet composition and prey selection reflected their respective habitat preferences, i.e. snow leopards significantly preferred cliff-dwelling wild ungulates (mainly bharal, 57% of identified material in scat samples), whereas wolves preferred typically plain-dwellers (Tibetan gazelle, kiang and argali, 31%). Livestock was consumed less frequently than their proportional availability by both predators (snow leopard = 27%; wolf = 24%), but significant avoidance was only detected among snow leopards. Among livestock species, snow leopards significantly preferred horses and goats, avoided yaks, and used sheep as available. We identified factors influencing diet composition using Generalized Linear Mixed Models. Wolves showed seasonal differences in the occurrence of small mammals/birds, probably due to the winter hibernation of an important prey, marmots. For snow leopard, occurrence of both wild ungulates and livestock in scats depended on sex and latitude. Wild ungulates occurrence increased while livestock decreased from south to north, probably due to a latitudinal gradient in prey availability. Livestock occurred more frequently in scats from male snow leopards (males: 47%, females: 21%), and wild ungulates more frequently in scats from females (males: 48%, females: 70%). The sexual difference agrees with previous

  11. Snow Leopard and Himalayan Wolf: Food Habits and Prey Selection in the Central Himalayas, Nepal.

    PubMed

    Chetri, Madhu; Odden, Morten; Wegge, Per

    2017-01-01

    Top carnivores play an important role in maintaining energy flow and functioning of the ecosystem, and a clear understanding of their diets and foraging strategies is essential for developing effective conservation strategies. In this paper, we compared diets and prey selection of snow leopards and wolves based on analyses of genotyped scats (snow leopards n = 182, wolves n = 57), collected within 26 sampling grid cells (5×5 km) that were distributed across a vast landscape of ca 5000 km2 in the Central Himalayas, Nepal. Within the grid cells, we sampled prey abundances using the double observer method. We found that interspecific differences in diet composition and prey selection reflected their respective habitat preferences, i.e. snow leopards significantly preferred cliff-dwelling wild ungulates (mainly bharal, 57% of identified material in scat samples), whereas wolves preferred typically plain-dwellers (Tibetan gazelle, kiang and argali, 31%). Livestock was consumed less frequently than their proportional availability by both predators (snow leopard = 27%; wolf = 24%), but significant avoidance was only detected among snow leopards. Among livestock species, snow leopards significantly preferred horses and goats, avoided yaks, and used sheep as available. We identified factors influencing diet composition using Generalized Linear Mixed Models. Wolves showed seasonal differences in the occurrence of small mammals/birds, probably due to the winter hibernation of an important prey, marmots. For snow leopard, occurrence of both wild ungulates and livestock in scats depended on sex and latitude. Wild ungulates occurrence increased while livestock decreased from south to north, probably due to a latitudinal gradient in prey availability. Livestock occurred more frequently in scats from male snow leopards (males: 47%, females: 21%), and wild ungulates more frequently in scats from females (males: 48%, females: 70%). The sexual difference agrees with previous

  12. Toxic effects of octylphenol on the expression of genes in liver identified by suppression subtractive hybridization of Rana chensinensis.

    PubMed

    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.

  13. Seasonal and diurnal calling patterns of Ross and leopards

    NASA Astrophysics Data System (ADS)

    Rogers, Tracey L.; Rowney, Gayle A.; Ciaglia, Michaela B.; Cato, Douglas H.

    2005-09-01

    The temporal calling patterns of two Antarctic pack ice seals, the leopard and Ross seal, were examined. This included seasonal onset and decline of calling (coinciding with their breeding season) as well as diurnal changes. Understanding of calling behavior has important implications for acoustic surveying, since this allows the number of calls to be related to an index of the number of animals present and to estimate abundance. The monthly changes in diurnal calling and haul-out patterns (measured via satellite telemetry) were compared. Underwater acoustic recordings were made between 14 October 2003 and 10 January 2004 off Mawson, Eastern Antarctica (660 44.243S and 690 48.748E). Recordings were made using an Acoustics Recording Package (ARP by Dr. John Hildebrand, Scripps Institute of Oceanography, La Jolla, CA) which is designed to sit on the seafloor and passively record acoustic signals. The package was deployed at a depth of 1320.7 m. The sampling rate was 500 Hz and the effective bandwidth from 10 to 250 Hz, covering the bandwidth of only the low-frequency calls of the Ross and leopard seal.

  14. Information entropy analysis of leopard seal vocalization bouts

    NASA Astrophysics Data System (ADS)

    Buck, John R.; Rogers, Tracey L.; Cato, Douglas H.

    2004-05-01

    Leopard seals (Hydrurga leptonyx) are solitary pinnipeds who are vocally active during their brief breeding season. The seals produce vocal bouts consisting of a sequence of distinct sounds, with an average length of roughly ten sounds. The sequential structure of the bouts is thought to be individually distinctive. Bouts recorded from five leopard seals during 1992-1994 were analyzed using information theory. The first-order Markov model entropy estimates were substantially smaller than the independent, identically distributed model entropy estimates for all five seals, indicative of constraints on the sequential structure of each seal's bouts. Each bout in the data set was classified using maximum-likelihood estimates from the first-order Markov model for each seal. This technique correctly classified 85% of the bouts, comparable to results in Rogers and Cato [Behaviour (2002)]. The relative entropies between the Markov models were found to be infinite in 18/20 possible cross-comparisons, indicating there is no probability of misclassifying the bouts in these 18 comparisons in the limit of long data sequences. One seal has sufficient data to compare a nonparametric entropy estimate with the Markov entropy estimate, finding only a small difference. This suggests that the first-order Markov model captures almost all the sequential structure in this seal's bouts.

  15. Conservation genetics of the Far Eastern leopard (Panthera pardus orientalis).

    PubMed

    Uphyrkina, O; Miquelle, D; Quigley, H; Driscoll, C; O'Brien, S J

    2002-01-01

    The Far Eastern or Amur leopard (Panthera pardus orientalis) survives today as a tiny relict population of 25-40 individuals in the Russian Far East. The population descends from a 19th-century northeastern Asian subspecies whose range extended over southeastern Russia, the Korean peninsula, and northeastern China. A molecular genetic survey of nuclear microsatellite and mitochondrial DNA (mtDNA) sequence variation validates subspecies distinctiveness but also reveals a markedly reduced level of genetic variation. The amount of genetic diversity measured is the lowest among leopard subspecies and is comparable to the genetically depleted Florida panther and Asiatic lion populations. When considered in the context of nonphysiological perils that threaten small populations (e.g., chance mortality, poaching, climatic extremes, and infectious disease), the genetic and demographic data indicate a critically diminished wild population under severe threat of extinction. An established captive population of P. p. orientalis displays much higher diversity than the wild population sample, but nearly all captive individuals are derived from a history of genetic admixture with the adjacent Chinese subspecies, P. p. japonensis. The conservation management implications of potential restoration/augmentation of the wild population with immigrants from the captive population are discussed.

  16. FROG - Fingerprinting Genomic Variation Ontology

    PubMed Central

    Bhardwaj, Anshu

    2015-01-01

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

  17. FROGS (Friends of Granites) report

    NASA Astrophysics Data System (ADS)

    Miller, Calvin

    This VGP News, which is devoted to petrology, is a good one for noting the existence of FROGS. FROGS is, as the name suggests, an informal organization of people whose research relates in one way or another to granitic rocks. Its purpose has been to promote communication among geoscientists with different perspectives and concerns about felsic plutonism. Initially, a major focus was experimental petrology and integration of field-oriented and lab-oriented viewpoints; now that there is the opportunity to communicate with the Eos readership, an obvious additional goal will be to bring together volcanic and plutonic views of felsic magmatism.FROGS first gathered in late 1982 under the guidance of E-an Zen and Pete Toulmin (both at U.S. Geological Survey (USGS), Reston, Va.), who saw a need for greater interaction among those interested in granites and for renewed, focused experimental investigations. They produced two newsletters (which were sent out by direct mail) and organized an informal meeting at the Geological Society of America meeting at Indianapolis, Ind., and then turned over the FROG reins to Sue Kieffer (USGS, Flagstaff, Ariz.) and John Clemens (Arizona State University, Tempe). They generated another newsletter, which was directly mailed to a readership that had grown beyond 200.

  18. FROG - Fingerprinting Genomic Variation Ontology.

    PubMed

    Abinaya, E; Narang, Pankaj; Bhardwaj, Anshu

    2015-01-01

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

  19. Care and Feeding of Frogs

    NASA Astrophysics Data System (ADS)

    Pan, Margaret; Chiang, Eugene

    2012-01-01

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

  20. CARE AND FEEDING OF FROGS

    SciTech Connect

    Pan, Margaret; Chiang, Eugene

    2012-01-15

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

  1. Freeze-thaw effects on metabolic enzymes in wood frog organs.

    PubMed

    Cowan, K J; Storey, K B

    2001-08-01

    To determine whether episodes of natural freezing and thawing altered the metabolic makeup of wood frog (Rana sylvatica) organs, the maximal activities of 28 enzymes of intermediary metabolism were assessed in six organs (brain, heart, kidney, liver, skeletal muscle, gut) of control (5 degrees C acclimated), frozen (24 h at -3 degrees C), and thawed (24 h back at 5 degrees C) frogs. The enzymes assessed represented pathways including glycolysis, gluconeo-genesis, amino acid metabolism, fatty acid metabolism, the TCA cycle, and adenylate metabolism. Organ-specific responses seen included (a) the number of enzymes affected by freeze-thaw (1 in gut ranging to 17 in heart), (b) the magnitude and direction of response (most often enzyme activities decreased during freezing and rebounded with thawing but, liver showed freeze-specific increases in several enzymes), and (c) the response to freezing versus thawing (enzyme activities in gut and kidney changed during freezing, whereas most enzymes in skeletal muscle responded to thawing). Overall, the data show that freeze-thaw implements selected changes to the maximal activities of various enzymes of intermediary metabolism and that these may aid organ-specific responses that alter fuel use during freeze-thaw, support cryoprotectant metabolism, and aid organ endurance of freeze-induced ischemia.

  2. Effects of Echinostoma trivolvis metacercariae infection during development and metamorphosis of the wood frog (Lithobates sylvaticus).

    PubMed

    Orlofske, Sarah A; Belden, Lisa K; Hopkins, William A

    2017-01-01

    Many organisms face energetic trade-offs between defense against parasites and other host processes that may determine overall consequences of infection. These trade-offs may be particularly evident during unfavorable environmental conditions or energetically demanding life history stages. Amphibian metamorphosis, an ecologically important developmental period, is associated with drastic morphological and physiological changes and substantial energetic costs. Effects of the trematode parasite Echinostoma trivolvis have been documented during early amphibian development, but effects during later development and metamorphosis are largely unknown. Using a laboratory experiment, we examined the energetic costs of late development and metamorphosis coupled with E. trivolvis infection in wood frogs, Lithobates [=Rana] sylvaticus. Echinostoma infection intensity did not differ between tadpoles examined prior to and after completing metamorphosis, suggesting that metacercariae were retained through metamorphosis. Infection with E. trivolvis contributed to a slower growth rate and longer development period prior to the initiation of metamorphosis. In contrast, E. trivolvis infection did not affect energy expenditure during late development or metamorphosis. Possible explanations for these results include the presence of parasites not interfering with pronephros degradation during metamorphosis or the mesonephros compensating for any parasite damage. Overall, the energetic costs of metamorphosis for wood frogs were comparable to other species with similar life history traits, but differed from a species with a much shorter duration of metamorphic climax. Our findings contribute to understanding the possible role of energetic trade-offs between parasite defense and host processes by considering parasite infection with simultaneous energetic demands during a sensitive period of development.

  3. Flow cytometry used to assess genetic damage in frogs from farm ponds

    USGS Publications Warehouse

    Bly, B.L.; Knutson, M.G.; Sandheinrich, M.B.; Gray, B.R.; Jobe, D.A.

    2004-01-01

    Flow cytometry (FC) is a laboratory method used to detect genetic damage induced by environmental contaminants and other stressors in animals, including amphibians. We tested FC methods on three species of ranid frogs collected from farm ponds and natural wetlands in southeastern Minnesota. We compared FC metrics for Rana clamitans between ponds with direct exposure to agricultural contaminants and reference (unexposed) ponds. Concentrations of atrazine in water from our farm ponds ranged from 0.04 to 0.55 ppb. We found that R. clamitans from exposed ponds had DNA content similar to frogs from unexposed ponds. Pond-averaged C-values (a measure of DNA content) ranged from 6.53 to 7.08 for R. pipiens (n . 13), 6.55 to 6.60 for R. clamitans (n . 40) and 6.74 for R. palustris (n . 5). Among all species, the mean sample CVs ranged from 1.91 (R. palustris) to 6.31 (R. pipiens). Deformities were observed in only 2 of 796 individuals among all species and occurred in both reference and exposed ponds. Although we did not detect evidence of DNA damage associated with agriculture in our study, we demonstrated the potential of FC for screening amphibian populations for genetic damage. Metrics from a variety of amphibian species and locations as well as laboratory studies are needed to further assess the value of FC for monitoring amphibian genetic integrity in contaminated sites.

  4. [Effect of padan on active sodium transport in the epithelium of isolated frog skin].

    PubMed

    Kontek, M; Pogorzelska, H; Knapowski, J

    1984-01-01

    The effects of " Padan " (hydrochloride of 1.3-di/ carbomylothio /-2-N-dimethylamino/propane/ upon transport capabilities of plasmatic membrane have been checked. The experiment was performed on isolated skin of Rana temporaria frogs. Assessment of transporting activity of membrane in relation to sodium ion involved a method developed by Ussing with so called "short-circuit" technique. The effects of the pesticide on the external and internal surface of the frog's skin have been examined, final concentrations of the compound being 3.4 X 10(-6) M to 3.4 X 10(-3) M. The results indicate that " Padan ", whether administered to the external or internal surface of the membrane, decreases the value of membrane potential and short-circuit current, which is indicative of membrane transport inhibition. The effect varies with pesticide concentration in the medium, though it is statistically significant only in concentration 3.4 X 10(-3) M. On the other hand, membrane resistance usually gets increased as the compound concentration in the medium increases. The results indicate that cellular membrane should be considered while explaining the mechanism of toxic effects of " Padan " upon organism.

  5. Effects of the herbicide triclopyr on metamorphic northern red-legged frogs.

    PubMed

    Yahnke, Amy E; Grue, Christian E; Hayes, Marc P; Pearman-Gillman, Schuyler

    2017-02-10

    Aquatic herbicides are used to manage invasive emergent plants in and around wetlands. Metamorphic frogs that emerge during the aquatic weed management season may be at risk of herbicide exposure. Metamorphic northern red-legged frogs (Rana aurora) were exposed to a triclopyr tank mix labelled for control of broadleaf emergent aquatic weeds such as invasive purple loosestrife (Lythrum salicaria). The tank mix consisted of Renovate® 3 (triclopyr triethylamine salt [TEA] 44.4%), the modified vegetable oil surfactant Competitor®, and marker dye Hi-Light®. Metamorphs were exposed to the tank mix and a clean-water control for 96 h, then reared in clean water for 60 d. Exposure to the tank mix resulted in no treatment-related mortalities, no effects on behavior immediately post-exposure, and no effects on body or liver condition indices. Exposure to the tank mix resulted in lethargy during exposure and a 1-d delay in completion of metamorphosis. Deformities present in the rearing population confounded results for some endpoints. Observed effects were minimal, especially compared to the potential for ecological impacts from unmanaged invasive plants. This article is protected by copyright. All rights reserved.

  6. Antimicrobial peptides from the skin secretions of the South-East Asian frog Hylarana erythraea (Ranidae).

    PubMed

    Al-Ghaferi, Nadia; Kolodziejek, Jolanta; Nowotny, Norbert; Coquet, Laurent; Jouenne, Thierry; Leprince, Jérôme; Vaudry, Hubert; King, Jay D; Conlon, J Michael

    2010-04-01

    Peptidomic analysis of norepinephrine-stimulated skin secretions of the South-East Asian frog Hylarana erythraea (formerly Rana erythraea partim) has led to the identification of multiple peptides with antimicrobial activity. Structural characterization of the peptides demonstrated that they belong to the brevinin-1 (3), brevinin-2 (2), esculentin-2 (4), and temporin (1) families. The values in parentheses indicate the number of paralogs. In addition, a peptide (GVIKSVLKGVAKTVALG ML.NH(2)) was isolated that shows some structural similarity to the brevinin-2-related peptides (B2RP) previously isolated from North American frogs of the genus Lithobates. A synthetic replicate of the species B2RP showed broad-spectrum growth inhibitory activity against reference strains of Escherichia coli (MIC=12.5 microM), Staphylococcus aureus (MIC=12.5 microM) and Candida albicans (MIC=50 microM) and was active against multidrug-resistant clinical isolates of Acetinobacter baumannii (MIC in the range 6-12.5 microM). The hemolytic activity of the peptide was relatively low (LC(50)=280 microM). Phylogenetic analysis based upon the amino acid sequences of 47 brevinin-2 peptides from 17 Asian species belonging to the family Ranidae provides support for the placement of H. erythraea in the genus Hylarana.

  7. Effects of sciatic nerve transection on ultrastructure, NADPH-diaphorase reaction and serotonin-, tyrosine hydroxylase-, c-Fos-, glucose transporter 1- and 3-like immunoreactivities in frog dorsal root ganglion

    PubMed Central

    Rigon, F.; Rossato, D.; Auler, V.B.; Dal Bosco, L.; Faccioni-Heuser, M.C.; Partata, W.A.

    2013-01-01

    Frogs have been used as an alternative model to study pain mechanisms. Since we did not find any reports on the effects of sciatic nerve transection (SNT) on the ultrastructure and pattern of metabolic substances in frog dorsal root ganglion (DRG) cells, in the present study, 18 adult male frogs (Rana catesbeiana) were divided into three experimental groups: naive (frogs not subjected to surgical manipulation), sham (frogs in which all surgical procedures to expose the sciatic nerve were used except transection of the nerve), and SNT (frogs in which the sciatic nerve was exposed and transected). After 3 days, the bilateral DRG of the sciatic nerve was collected and used for transmission electron microscopy. Immunohistochemistry was used to detect reactivity for glucose transporter (Glut) types 1 and 3, tyrosine hydroxylase, serotonin and c-Fos, as well as nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase). SNT induced more mitochondria with vacuolation in neurons, satellite glial cells (SGCs) with more cytoplasmic extensions emerging from cell bodies, as well as more ribosomes, rough endoplasmic reticulum, intermediate filaments and mitochondria. c-Fos immunoreactivity was found in neuronal nuclei. More neurons and SGCs surrounded by tyrosine hydroxylase-like immunoreactivity were found. No change occurred in serotonin- and Glut1- and Glut3-like immunoreactivity. NADPH-diaphorase occurred in more neurons and SGCs. No sign of SGC proliferation was observed. Since the changes of frog DRG in response to nerve injury are similar to those of mammals, frogs should be a valid experimental model for the study of the effects of SNT, a condition that still has many unanswered questions. PMID:23739744

  8. MicroRNA regulation in heart and skeletal muscle over the freeze-thaw cycle in the freeze tolerant wood frog.

    PubMed

    Bansal, Saumya; Luu, Bryan E; Storey, Kenneth B

    2016-02-01

    The North American wood frog, Rana sylvatica, is one of just a few anuran species that tolerates whole body freezing during the winter and has been intensely studied to identify the biochemical adaptations that support freeze tolerance. Among these adaptations is the altered expression of many genes, making freeze-responsive changes to gene regulatory mechanisms a topic of interest. The present study focuses on the potential involvement of microRNAs as one such regulatory mechanism and aims to better understand freeze/thaw stress-induced microRNA responses in the freeze-tolerant wood frog. Using quantitative PCR, relative levels of 53 microRNAs were measured in heart and skeletal muscle of control, 24 h frozen, and 8 h thawed frogs. MicroRNAs showed tissue specific expression patterns: 21 microRNAs decreased in the heart during thawing, whereas 16 microRNAs increased during freezing stress in skeletal muscle. These findings suggest that select genes may be activated and suppressed in heart and skeletal muscle, respectively, in response to freezing. Bioinformatics analysis using the DIANA miRPath program (v.2.0) predicted that the differentially expressed microRNAs may collectively regulate tissue-specific cellular pathways to promote survival of wood frogs undergoing freezing and thawing.

  9. Comparison of thyroid hormone-dependent gene responses in vivo and in organ culture of the American bullfrog (Rana (Lithobates) catesbeiana) lung.

    PubMed

    Veldhoen, Nik; Stevenson, Mitchel R; Helbing, Caren C

    2015-12-01

    Postembryonic frog development requires a thyroid hormone (TH)-dependent metamorphic transition from an aquatic larva to a terrestrial frog. Such change in environment involves lung maturation in preparation for breathing air. However, little is known regarding the underlying molecular events and the role of THs in this process. Using quantitative real-time polymerase chain reaction, we evaluated Rana (Lithobates) catesbeiana lung mRNA transcripts representing key elements of TH and