| chromosomal aberrations induced by dispersion yellow 3 in rana clamitans larvae during tail regeneration. | azo dyes have been shown to be mutagenic and toxic in a variety of organisms. the azo dye, dispersion yellow 3 is a pollutant in the river water supply of northern georgia. preliminary and definitive studies have indicated that it is mutagenic in micro-organisms and causes several malformations in chicken embryos. the present study revealed that when larvae are exposed to the dye during tail regeneration, several aberrations are seen in the squash preparations from regenerates. included are gaps ... | 1979 | 546599 |
| periodicities and transient shifts in anuran (xenopus laevis, rana clamitans) oxygen consumption revealed with flow-through respirometry. | 1. a custom-designed, computer-controlled, flow-through respirometry system was used to monitor oxygen consumption in aquatic anurans: xenopus laevis metamorphs and larval rana clamitans. 2. there was no evidence that animals were stressed in the flow-through respirometer; oxygen consumption rates in static vs open mode fell within the same range and animals were quiescent in the chambers. 3. diurnal periodicity was pronounced in x. laevis: both mean rates and variability of oxygen consumption w ... | 1992 | 1348672 |
| evidence for host allozymes present on electrophoretic gels of trematode parasites (digenea: plagiorchiiformes). | an allozyme analysis of trematode species glypthelmins californiensis, glypthelmins quieta, glypthelmins pennsylvaniensis, glypthelmins hyloreus, and haplometrana intestinalis from hosts rana aurora, rana clamitans, hyla crucifer, pseudacris triseriata, and rana pretiosa, using starch gel electrophoresis, revealed allozymes for glucose-phosphate isomerase, lactate dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase that were similar in electrophoretic mobility to host tissue contro ... | 1991 | 1919938 |
| helminth infracommunities of the frogs rana catesbeiana and rana clamitans from turkey marsh, michigan. | one hundred twenty-seven bullfrogs, rana catesbeiana, and 120 green frogs, rana clamitans, collected in july and august 1987 from turkey marsh, michigan, were examined for helminths. of the 16 helminth species found, falcaustra catesbeianae had the highest prevalence and mean intensity in bullfrogs. in green frogs, megalodiscus temperatus had the highest prevalence and haematoloechus parviplexus had the highest mean intensity. taxonomically, 1,030 (30.5%) trematodes and 2,348 (69.5%) nematodes o ... | 1991 | 2040950 |
| changes in plasma thyroxine levels during and after spontaneous metamorphosis in a natural population of the green frog, rana clamitans. | plasma thyroxine (t4) levels were measured by radioimmunoassay in a spontaneously metamorphosing population of green frog, rana clamitans, tadpoles. in accordance with species previously studied, a sharp rise in plasma t4 was seen at metamorphic climax, followed by a decline at final transformation. unlike other species studied thus far, t4 levels were also moderately high in growing tadpoles (stages x-xiii). these early elevated levels may be due to daily rhythmicity in thyroid secretion couple ... | 1986 | 3491018 |
| aegyptianella ranarum sp. n. (rickettsiales, anaplasmataceae): ultrastructure and prevalence in frogs from ontario. | aegyptianella ranarum sp. n. (rickettsiales, anaplasmataceae) was recorded from bullfrogs (rana catesbeiana shaw), green frogs (rana clamitans latreille) and mink frogs (rana septentrionalis baird) from five sites in southern ontario. the rickettsia occurs within membrane-bound vacuoles in the cytoplasm of erythrocytes with up to 120 organisms in mature inclusions. the pattern of replication of a. ranarum in host erythrocytes and its prevalence over a 3-yr period in frogs from algonquin park, on ... | 1987 | 3493355 |
| the uptake and effects of lead in small mammals and frogs at a trap and skeet range. | this study was performed to evaluate the bioavailability and effects of lead in wildlife at a trap and skeet range. the total lead concentration in a composite soil sample (pellets removed) was 75,000 micrograms/g dry weight. elevated tissue lead concentrations and depressed alad activities in small mammals and frogs indicate that some of the lead deposited at the site is bioavailable. mean tissue lead concentrations (micrograms/g dry wt.) in white-footed mice (peromyscus leucopus) at the range ... | 1996 | 8593083 |
| caged amphibian tadpoles and in situ genotoxicity monitoring of aquatic environments with the alkaline single cell gel electrophoresis (comet) assay. | in previous studies we demonstrated that indigenous amphibian tadpoles are suitable organisms for monitoring small bodies of water (e.g., creeks, ponds, and drainage ditches) using the alkaline single cell gel electrophoresis (scg) or 'comet' assay. this approach involves detection, under alkaline conditions, of cell dna fragments which on electrophoresis migrate from the nuclear core, resulting in a 'comet with tail' formation. however, although often plentiful, tadpoles are not present in all ... | 1998 | 9651536 |
| the life history and host specificity of hepatozoon clamatae (apicomplexa: adeleorina) and its-1 nucleotide sequence variation of hepatozoon species of frogs and mosquitoes from ontario. | the life cycle of an intraerythrocytic hemogregarine, hepatozoon clamatae, was studied in green frogs (rana clamitans melanota), bullfrogs (rana catesbeiana), northern leopard frogs (rana pipiens), and in the mosquito, culex territans. gametogenesis, fertilization, and sporogony occurred within cells of the malpighian tubules of laboratory-reared cx. territans that had fed on naturally infected frogs. mature oocysts containing hundreds of sporocysts were observed in mosquitoes 30 days postfeedin ... | 1998 | 9714212 |
| phylogenetic relationships among hepatozoon species from snakes, frogs and mosquitoes of ontario, canada, determined by its-1 nucleotide sequences and life-cycle, morphological and developmental characteristics. | the molecular biological characteristics of hepatozoon species infecting various species of snakes, frogs and mosquitoes were investigated by determining the nucleotide sequences of the first internal transcribed spacer region. a phylogenetic analysis was performed on seven isolates of hepatozoon infecting snakes, including hepatozoon sipedon and four morphologically similar but not identical forms, and two isolates of hepatozoon catesbianae infecting green frogs (rana clamitans melanota). this ... | 1999 | 10221630 |
| purification and characterization of antimicrobial peptides from the skin of the north american green frog rana clamitans. | ten peptides with differential growth-inhibitory activity against the gram-positive bacterium, staphylococcus aureus, the gram-negative bacterium, escherichia coli, and the yeast candida albicans were isolated from an extract of the skin of a north american frog, the green frog rana clamitans. ranatuerin-1c (smlsvlknlgkvglglvackinkqc), ranalexin-1ca (flgglmkafpalicavtkkc), ranalexin-1cb (flgglmkafpaiicavtkkc), ranatuerin-2ca (glfldtlkgaakdvagklleglkckiagc kp), and ranatuerin-2cb (glfldtlkglagkll ... | 2000 | 10822101 |
| intraerythrocytic development of species of hepatozoon infecting ranid frogs: evidence for convergence of life cycle characteristics among apicomplexans. | intraerythrocytic development of the adeleorin apicomplexans hepatozoon clamatae and hepatozoon catesbianae were investigated in the bullfrog, rana catesbeiana, the green frog, rana clamitans melanota, and the northern leopard frog, rana pipiens. merozoites emerging from hepatic meronts penetrated erythrocytes and underwent 1-3 rounds of binary fission to produce 2-8 merozoites. following their release from infected erythrocytes, individual merozoites entered new cells and transformed into gamon ... | 2000 | 10864239 |
| helminth communities of green frogs rana clamitans latreille, from southwestern michigan. | a total of 239 green frogs rana clamitans, collected between june 3 and august 27, 1998 from 6 locations in southwestern michigan, was examined for helminths. of the 26 helminth taxa found, the larval cestode mesocestoides sp. had the highest mean intensity, followed by the larval trematode fibricola sp. of the helminths that mature in frogs, haematoloechus varioplexus had the highest prevalence and gorgodera amplicava had the highest mean intensity. frogs from 118th pond had the highest species ... | 2001 | 11695416 |
| effect of ph and release on two life stages of four anuran amphibians. | using three native canadian and one exotic anuran species, the interactive toxicity of ph and the forestry used-herbicide release (triclopyr [3,5,6-trichloro-2-pyridl-oxyacetic acid]) was assessed. embryonic and larval (gosner 25) stages of rana pipiens, rana clamitans, bufo americanus, and xenopus laevis were exposed to treatments for at least 96 h in a static-renewal system using a central composite rotatable design. mortality and the prevalence of malformations were modeled using generalized ... | 2003 | 14587907 |
| effects of carbaryl on green frog (rana clamitans) tadpoles: timing of exposure versus multiple exposures. | 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 wer ... | 2003 | 14587910 |
| comparative effects of ph and vision herbicide on two life stages of four anuran amphibian species. | vision, a glyphosate-based herbicide containing a 15% (weight:weight) polyethoxylated tallow amine surfactant blend, and the concurrent factor of ph were tested to determine their interactive effects on early life-stage anurans. ninety-six-hour laboratory static renewal studies, using the embryonic and larval life stages (gosner 25) of rana clamitans, r. pipiens, bufo americanus, and xenopus laevis, were performed under a central composite rotatable design. mortality and the prevalence of malfor ... | 2004 | 15095875 |
| impact of atrazine on chlorpyrifos toxicity in four aquatic vertebrates. | atrazine has been shown previously to potentiate chlorpyrifos toxicity in selected invertebrates. this study examined interactions of atrazine and chlorpyrifos in four aquatic vertebrates. organisms were exposed to binary mixtures of atrazine and chlorpyrifos during toxicity bioassays. inhibition of cholinesterase (che) enzyme activity and chlorpyrifos uptake kinetics were also examined with and without atrazine exposure. atrazine alone did not affect organisms at concentrations up to 5000 micro ... | 2006 | 16944040 |
| bioremediation of tetrachloroethylene-contaminated groundwater in a model aquifer: effects on green frogs (rana clamitans) and xenopus laevis as potential wetland receptors. | recent regulations require that the ecological effects of microorganisms introduced into the environment, such as for groundwater bioremediation, be assessed prior to their utilization. a native anuran (rana clamitans) and a model anuran (xenopus laevis) were used as potential wetland receptors of tetrachloroethylene (pce)-contaminated groundwater, undergoing three bioremediation treatments: natural attenuation (na), biostimulation (st), and bioaugmentation (au). eggs of both species were expose ... | 2007 | 17253100 |
| mercury bioaccumulation in green frog (rana clamitans) and bullfrog (rana catesbeiana) tadpoles from acadia national park, maine, usa. | mercury contamination in the northeastern united states, including acadia national park (anp; me, usa), is well documented and continues to be a public health issue of concern. mercury contamination of wild amphibians has received little attention, however, despite reports of worldwide population declines. here, we report total hg and methyl hg (mehg) concentrations for water, sediment, and green frog (rana clamitans) and bullfrog (rana catesbeiana) tadpoles (age, approximately one year) from an ... | 2007 | 17269468 |
| frog virus 3 prevalence in tadpole populations inhabiting cattle-access and non-access wetlands in tennessee, usa. | ranaviruses have been associated with most of the reported larval anuran die-offs in the united states. it is hypothesized that anthropogenically induced stress may increase pathogen prevalence in amphibian populations by compromising immunity. cattle use of wetlands may stress resident tadpole populations by reducing water quality. we isolated a ranavirus from green frog rana clamitans (n = 80) and american bullfrog r. catesbeiana (n = 104) tadpoles collected at 5 cattle-access and 3 non-access ... | 2007 | 17972750 |
| echinostome metacercariae cyst elimination in rana clamitans (green frog) tadpoles is age-dependent. | host response to parasite exposure is an important determinant of the outcome of host-parasite interactions. factors such as host body condition and age can strongly influence host response to parasites and infection. this study followed echinostoma revolutum infection levels in larval green frogs (rana clamitans) exposed at 2 different ages. tadpoles at early developmental stages are more susceptible to the adverse effects of echinostomes. green frog tadpoles approximately 2 wk apart in age and ... | 2009 | 18850770 |
| single and interactive effects of malathion, overwintered green frog tadpoles, and cyanobacteria on gray treefrog tadpoles. | amphibian population declines around the world are associated with invasive species, pesticides, pathogens, habitat destruction, or a combination of factors. because contamination is widespread, it represents a relevant environmental stress that can affect the ability of organisms to deal with other factors present in the environment. we examined the effects of the insecticide malathion, larger tadpole competitors (green frogs, rana clamitans), and a toxic cyanobacteria (anabaena spp.) on tadpol ... | 2009 | 18937534 |
| relationships between leukocytes and hepatozoon spp. in green frogs, rana clamitans. | there are few published data on amphibian leukocyte profiles, and relationships between amphibian leukocytes and parasites are even less well known. using counts from 35 pairs of blood smears taken 2 days apart, we tested for correlations between leukocyte proportions and infection intensities of hepatozoon spp. (either hepatozoon catesbianae or hepatozoon clamatae) in green frogs (rana clamitans). on average (se), we counted 65.4 (1.7) lymphocytes, 14.0 (1.3) neutrophils, 19.3 (1.6) eosinophils ... | 2009 | 19204336 |
| pathologic findings in larval and juvenile anurans inhabiting farm ponds in tennessee, usa. | amphibian populations are declining globally, yet general pathologic surveys for free-ranging amphibians are uncommon. pathologic surveys are necessary to provide insight into the impacts of humans on emergence of pathogens in amphibian populations. during 2005, 104 american bullfrog (rana catesbeiana) and 80 green frog (rana clamitans) larvae and 40 green frog juveniles were collected from farm ponds in tennessee, and complete necropsies were performed. diagnostic testing included bacterial cul ... | 2009 | 19395741 |
| experimental infection of native north carolina salamanders with batrachochytrium dendrobatidis. | chytridiomycosis is an often fatal fungal disease of amphibians caused by batrachochytrium dendrobatidis. this disease has been implicated in the worldwide decline of many anuran species, but studies of chytridiomycosis in wild salamanders are limited. between august 2006 and december 2006, we tested wild amphibians in north carolina, usa (n=212) by polymerase chain reaction (pcr). we identified three pcr-positive animals: one rana clamitans and two plethodontid salamanders. we experimentally in ... | 2009 | 19617473 |
| experimental transmission of hepatozoon clamatae (apicomplexa: adeleida) to the wood frog, rana sylvatica, and to the mosquito culex pipiens. | hepatozoon clamatae naturally infects the erythrocytes of green frogs (rana clamitans), bullfrogs (rana catesbeiana), and northern leopard frogs (rana pipiens) in northeastern north america and uses the mosquito culex territans as a definitive host. in this study, we show that the wood frog, rana sylvatica, supports merogonic development, but not gamogonic development, of this protozoan parasite, and that the mosquito culex pipiens serves as an experimental definitive host for sporogonic develop ... | 2010 | 19895159 |
| effects of two amphibian pathogens on the developmental stability of green frogs. | developmental instability, measured as fluctuating asymmetry (fa), is often used as a tool to measure stress and the overall quality of organisms. under fa, it is assumed that control of symmetry during development is costly and that under stress the trajectory of development is disturbed, resulting in asymmetric morphologies. amphibian emergent infectious diseases (eids), such as ranavirus and chytrid fungus, have been involved in several mortality events, which makes them stressors and allows ... | 2010 | 20067485 |
| echinostome-induced mortality varies across amphibian species in the field. | echinostomes are receiving increased attention because of their emerging parasite status in landscapes associated with human development and their ability to infect and kill many north american larval amphibians. while laboratory experiments have shown that echinostomes can cause extensive mortality in their amphibian hosts, their effect on tadpoles in the field is less clear. i conducted a controlled-infection field-enclosure experiment in 4 ponds to compare the effects of echinostomes on green ... | 2010 | 20469948 |
| prevalence of batrachochytrium dendrobatidis in three species of wild frogs on prince edward island, canada. | 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 t ... | 2010 | 21387987 |
| exposure of juvenile green frogs (lithobates clamitans) in littoral enclosures to a glyphosate-based herbicide. | the majority of studies on the toxicity of glyphosate-based herbicides to amphibians have focused on larval life stages exposed in aqueous media. however, adult and juvenile amphibians may also be exposed directly or indirectly to herbicides. the potential for such exposures is of particular interest in the littoral zone surrounding wetlands as this is preferred habitat for many amphibian species. moreover, it may be argued that potential herbicide effects on juvenile or adult amphibians could h ... | 2011 | 21536331 |
| laboratory and field exposure of two species of juvenile amphibians to a glyphosate-based herbicide and batrachochytrium dendrobatidis. | herbicides are commonly used in agriculture and silviculture to reduce interspecific competition among plants and thereby enhance crop growth, quality, and volume. internationally, formulations of glyphosate-based herbicides are the most widely used herbicides in both these sectors. a large amount of work has focused on the effects of these herbicides on amphibians. several laboratory and mesocosm studies have demonstrated that various formulations of glyphosate herbicides can be acutely toxic t ... | 2012 | 23262329 |
| seasonal infection rates of batrachochytrium dendrobatidis in populations of northern green frog lithobates clamitans melanota tadpoles. | few studies have documented seasonal variation of batrachochytrium dendrobatidis (bd) infection rates in larval amphibians. we identified 4 natural populations of northern green frogs lithobates clamitans melanota in pennsylvania (usa) that contained bd-infected tadpoles during post-wintering collections in may and june, after hibernating tadpoles had overwintered in wetlands. however, we failed to detect infected tadpoles at those wetlands when pre-wintering collections were made in late july t ... | 2016 | 27667807 |
| disease dynamics of red-spotted newts and their anuran prey in a montane pond community. | long-term monitoring of amphibians is needed to clarify population-level effects of ranaviruses (rv) and the fungal pathogen batrachochytrium dendrobatidis (bd). we investigated disease dynamics of co-occurring amphibian species and potential demographic consequences of rv and bd infections at a montane site in the southern appalachians, georgia, usa. our 3-yr study was unique in combining disease surveillance with intensive population monitoring at a site where both pathogens are present. we de ... | 2016 | 26912042 |
| direct and indirect horizontal transmission of the antifungal probiotic bacterium janthinobacterium lividum on green frog (lithobates clamitans) tadpoles. | amphibian populations worldwide are being threatened by the disease chytridiomycosis, which is caused by batrachochytrium dendrobatidis to mitigate the effects of b. dendrobatidis, bioaugmentation of antifungal bacteria has been shown to be a promising strategy. one way to implement bioaugmentation is through indirect horizontal transmission, defined as the transfer of bacteria from a host to the environment and to another host. in addition, direct horizontal transmission among individuals can f ... | 2016 | 26873311 |
| temperature alone does not explain patterns of batrachochytrium dendrobatidis infections in the green frog lithobates clamitans. | batrachochytrium dendrobatidis (bd) is an invasive, waterborne fungal pathogen that has caused significant declines and extinctions of amphibian species worldwide. temperature is a major factor impacting the growth and spread of bd, but little is known regarding the associated patterns in natural habitats. this study analyzed the temperature-associated trends, as correlated with season and microhabitat, of bd prevalence and infection intensity in green frogs lithobates clamitans in a temperate e ... | 2014 | 24991844 |
| disease risk in temperate amphibian populations is higher at closed-canopy sites. | habitat loss and chytridiomycosis (a disease caused by the chytrid fungus batrachochytrium dendrobatidis - bd) are major drivers of amphibian declines worldwide. habitat loss regulates host-pathogen interactions by altering biotic and abiotic factors directly linked to both host and pathogen fitness. therefore, studies investigating the links between natural vegetation and chytridiomycosis require integrative approaches to control for the multitude of possible interactions of biological and envi ... | 2012 | 23118953 |
| guinea worm (dracunculus medinensis) infection in a wild-caught frog, chad. | a third-stage (infective) larva of dracunculus medinensis, the causative agent of guinea worm disease, was recovered from a wild-caught phrynobatrachus francisci frog in chad. although green frogs (lithobates clamitans) have been experimentally infected with d. medinensis worms, our findings prove that frogs can serve as natural paratenic hosts. | 2016 | 27560598 |
| possible role of fish and frogs as paratenic hosts of dracunculus medinensis, chad. | 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 ... | 2016 | 27434418 |
| host food resource supplementation increases echinostome infection in larval anurans. | host-parasite interactions are often influenced by environmental factors through multiple mechanisms. for example, changes in host food resources may affect multiple host traits (e.g., body size, behavior, immunocompetence), which may increase or decrease infection levels and the impact of parasites on host fitness. we often lack an understanding of which traits are most important for parasite transmission and fitness effects, posing challenges to predicting consequences of changing environmenta ... | 2016 | 27581843 |
| low detection of ranavirus dna in wild postmetamorphic green frogs, rana (lithobates) clamitans, despite previous or concurrent tadpole mortality. | ranavirus (iridoviridae) infection is a significant cause of mortality in amphibians. detection of infected individuals, particularly carriers, is necessary to prevent and control outbreaks. recently, the use of toe clips to detect ranavirus infection through pcr was proposed as an alternative to the more frequently used lethal liver sampling in green frogs (rana [lithobates] clamitans). we attempted reevaluate the use of toe clips, evaluate the potential use of blood onto filter paper and hepat ... | 2013 | 24502715 |
| the complete mitochondrial genome sequence of hepatozoon catesbianae (apicomplexa: coccidia: adeleorina), a blood parasite of the green frog, lithobates (formerly rana) clamitans. | a complete mitochondrial genome for the blood parasite hepatozoon catesbianae (alveolata; apicomplexa; coccidia; adeleorina; hepatozoidae) was obtained through pcr amplification and direct sequencing of resulting pcr products. the mitochondrial genome of h. catesbianae is 6,397 bp in length and contains 3 protein-coding genes (cytochrome c oxidase subunit i [coi]; cytochrome c oxidase subunit iii [coiii]; and cytochrome b [cytb]). sequence similarities to previously published mitochondrial genom ... | 2014 | 24820055 |
| host and parasite thermal acclimation responses depend on the stage of infection. | global climate change is expected to alter patterns of temperature variability, which could influence species interactions including parasitism. species interactions can be difficult to predict in variable-temperature environments because of thermal acclimation responses, i.e. physiological changes that allow organisms to adjust to a new temperature following a temperature shift. the goal of this study was to determine how thermal acclimation influences host resistance to infection and to test f ... | 2016 | 27040618 |
| host density and competency determine the effects of host diversity on trematode parasite infection. | variation in host species composition can dramatically alter parasite transmission in natural communities. whether diverse host communities dilute or amplify parasite transmission is thought to depend critically on species traits, particularly on how hosts affect each other's densities, and their relative competency as hosts. here we studied a community of potential hosts and/or decoys (i.e. non-competent hosts) for two trematode parasite species, echinostoma trivolvis and ribeiroia ondatrae, wh ... | 2014 | 25119568 |
| studies on frog trypanosomiasis. i. a 24-hour cycle in the parasitemia level of trypanosoma rotatorium in rana clamitans from louisiana. | | 1968 | 5647105 |
| when can embryos learn? a test of the timing of learning in embryonic amphibians. | learning is crucial to the survival of organisms across their life span, including during embryonic development. we set out to determine when learning becomes possible in amphibian development by exposing spotted salamander (ambystoma maculatum) embryos to chemical stimuli from a predator (ambystoma opacum), nonpredator (lithobates clamitans), or control at developmental stages 16-21 or 36-38 (harrison 1969). once exposures were completed and embryos hatched, we recorded the number of movements ... | 2016 | 27110353 |
| arsenic species and uptake in amphibians (rana clamitans and bufo americanus). | total arsenic concentrations and the chemical form, or species, of arsenic were determined in amphibians (rana clamitans and bufo americanus) collected from a site with elevated arsenic concentrations in nova scotia, canada. frog legs had significantly elevated total arsenic concentrations at a contaminated site when compared with a nearby background site and a calculation of the estimated daily intake rates of arsenic indicates that both diet (invertebrate intake) and water absorption are impor ... | 2013 | 23788261 |
| toxicity of road salt to nova scotia amphibians. | the deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. in northern latitudes, a major pollutant in runoff water is salt (nacl), used as de-icing agents. in this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. acute toxicity tests (lc(50)) were performed on five locally common amphibian species using a range of environmentally significant nacl concentrations. field surveys indicated that spotte ... | 2009 | 18684543 |
| effects of timber harvesting on pond-breeding amphibian persistence: testing the evacuation hypothesis. | numerous studies have documented the decline of amphibians following timber harvest. however, direct evidence concerning the mechanisms of population decline is lacking and hinders attempts to develop conservation or recovery plans and solutions for forest species. we summarized the mechanisms by which abundance of amphibians may initially decline following timber harvest into three testable hypotheses: (1) mortality, (2) retreat, and (3) evacuation. here, we tested the evacuation hypothesis wit ... | 2008 | 18488596 |
| examining the single and interactive effects of three insecticides on amphibian metamorphosis. | although aquatic communities frequently are exposed to a number of pesticides, the effects of chemical mixtures are not well understood. in two separate studies, i examined how insecticide mixtures influenced the likelihood of unpredictable, nonadditive effects on american toad (bufo americanus) and green frog (rana clamitans) tadpoles reared in outdoor aquatic communities. i exposed tadpoles to single or multiple insecticides at approximately half the reported median lethal concentrations using ... | 2008 | 18260698 |
| toxicity of glyphosate-based pesticides to four north american frog species. | glyphosate-based herbicides are among the most widely used pesticides in the world. we compared the acute toxicity of the glyphosate end-use formulation roundup original to four north american amphibian species (rana clamitans, r. pipiens, r. sylvatica, and bufo americanus) and the toxicity of glyphosate technical, the polyethoxylated tallowamine surfactant (poea) commonly used in glyphosate-based herbicides, and five newer glyphosate formulations to r. clamitans. for r. clamitans, acute toxicit ... | 2004 | 15352482 |
| survivorship patterns of larval amphibians exposed to low concentrations of atrazine. | amphibians can be exposed to contaminants in nature by many routes, but perhaps the most likely route is agricultural runoff in amphibian breeding sites. this runoff results in high-level pulses of pesticides. for example, atrazine, the most widely used pesticide in the united states, can be present at several parts per million in agricultural runoff. however, pesticide levels are likely to remain in the environment at low levels for longer periods. nevertheless, most studies designed to examine ... | 2004 | 15238276 |
| chromogranin a-immunoreactive cells in the olfactory system of anuran amphibians. | chromogranin a (cga) is a member of the granin family of acidic proteins that are present in the secretory granules of many endocrine and neuroendocrine cells. the specific function(s) of these proteins is not known, but they seem to be the precursors of biologically active peptides, and they may act as helper proteins in the sorting and packaging of peptide hormones and neuropeptides. using indirect immunohistochemistry, we have found cga immunoreactivity in the primary olfactory epithelia, the ... | 2000 | 11042007 |
| hindlimb deformities (ectromelia, ectrodactyly) in free-living anurans from agricultural habitats. | high prevalences of hindlimb deformities were recorded in wild-caught green frogs (rana clamitans), northern leopard frogs (rana pipiens), american toads, (bufo americanus), and bullfrogs (rana catesbeiana) from agricultural sites exposed to pesticide runoff in the st. lawrence river valley of québec, canada, between july and september 1992 and 1993. of 853 metamorphosing anurans examined in 14 farmland habitats, 106 (12%; range 0 to 69%) had severe degrees of ectromelia and ectrodactyly, compar ... | 1997 | 9027696 |
| alkaline single-cell gel (comet) assay and genotoxicity monitoring using two species of tadpoles. | small bodies of water (e.g., creeks, ponds, and drainage ditches) have received very little attention in genotoxicity studies, yet these areas are important because they are often the first to be affected by industrial effluents, sewage contaminants, accidental spills, internal combustion engine emissions, landfill runoffs, and pesticide uses. to address this deficiency, we examined erythrocytes in two species of tadpoles, rana clamitans and bufo americanus, using the alkaline single-cell gel (s ... | 1996 | 8844992 |
| allozyme comparison of three trypanosoma species (kinetoplastida: trypanosomatidae) of toads and frogs by starch-gel electrophoresis. | six metabolic enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, phosphoglucomutase, and purine nucleoside phosphorylase, from clonal isolates of 3 presumptive species of trypanosoma (t. fallisi, t. ranarum, and t. rotatorium) from 3 anuran hosts (bufo americanus, rana clamitans, and rana catesbeiana) were compared using starch-gel electrophoresis. although bands were shared among the different zymodemes of isolates of the same ... | 1992 | 1556645 |
| infectivity of cultured trypanosoma fallisi (kinetoplastida) to various anuran species and its evolutionary implications. | trypanosoma fallisi, a hemoflagellate infecting bufo americanus from ontario, was grown in vitro, and metatrypanosomes from the primary culture were inoculated into 4 uninfected test groups from 3 anuran families: bufonidae, hylidae, and ranidae. in vitro-cultured t. fallisi was found to infect b. americanus and to induce transient infections in bufo valliceps and hyla versicolor. the flagellate was not infective to rana clamitans. trypanosoma ranarum was uninfective to the bufonids and hylids t ... | 1991 | 2040964 |
| post-metamorphic change in activity metabolism of anurans in relation to life history. | newly-metamorphosed individuals of some species of frogs and toads differ from adults in behavior, ecology, and physiology. these differences may be related to broader patterns of the life histories of different species of frogs. in particular, the length of larval life and the size of a frog at metamorphosis appear to be significant factors in post-metamorphic ontogenetic change. these changes in performance are associated with rapid post-metamorphic increases in oxygen transport capacity. bufo ... | 1984 | 28312123 |
| blood parasites of amphibians from algonquin park, ontario. | during a 5 wk period beginning may 25, 1983, 329 amphibians, which included specimens of rana catesbeiana shaw, rana clamitans latreille, rana septentrionalis baird, rana sylvatica leconte, hyla crucifer wied, bufo americanus holbrook, and plethodon cinereus green, from lake sasajewun, algonquin park, ontario, canada were examined for blood parasites. the prevalences of species of trypanosoma, haemogregarina, lankesterella, babesiasoma, and thrombocytozoons in these amphibians were determined. t ... | 1984 | 6492319 |
| temporal and spatial synchrony of culex territans (diptera: culicidae) with their amphibian hosts. | culex territans walker (diptera: culicidae) larvae share nonpolluted freshwater habitats with amphibians, which are bloodmeal hosts of their adults. to examine synchrony of cx. territans with amphibian species, 10 larval habitat sites were sampled weekly from march to november of 2004. cx. territans larvae were temporally and spatially associated with the green frog, rana clamitans latrielle. we predicted that if the preferred hosts were abundant at low temperatures, cx. territans might be able ... | 2008 | 19058626 |
| vertebrate hosts and phylogenetic relationships of amphibian trypanosomes from a potential invertebrate vector, culex territans walker (diptera: culicidae). | the blood meals of field-collected female culex territans (diptera: culicidae) were concurrently assayed for the presence of trypanosomes and for vertebrate host identification. we amplified vertebrate dna in 42 of 119 females and made positive identification to the host species level in 29 of those samples. of the 119 field-collected cx. territans females, 24 were infected with trypanosomes. phylogenetic analysis placed the trypanosomes in the amphibian portion of the aquatic clade of the trypa ... | 2009 | 18850768 |
| fine structure of the larval anuran epidermis, with special reference to the figures of eberth. | small pieces of skin from 8 cm long rana clamitans larvae were fixed in oso(4), washed, dehydrated, and embedded in a methacrylate mixture. ultrathin sections were cut on a porter-blum ultramicrotome and were examined in an rca electron microscope, type emu 2d. the sections showed that aggregates of fibrous material in the cells of the inner layer of epidermal cells are identical in disposition and size with the classical figures of eberth. it is conclusively shown that these figures do not aris ... | 1961 | 13692395 |
| sex-linked markers in the north american green frog (rana clamitans) developed using dartseq provide early insight into sex chromosome evolution. | the extent to which sex reversal is associated with transitions in sex determining systems (xx-xy, zz-zw, etc.) or abnormal sexual differentiation is predominantly unexplored in amphibians. this is in large part because most amphibian taxa have homomorphic sex chromosomes, which has traditionally made it challenging to identify discordance between phenotypic and genetic sex in amphibians, despite all amphibians having a genetic component to sex determination. recent advances in molecular techniq ... | 2016 | 27793086 |
| a new species of eimeria (apicomplexa: eimeriidae) from green frog, lithobates clamitans (anura: ranidae) from arkansas, u.s.a. | between april and october 2012, 20 juvenile and adult green frogs (lithobates clamitans) were collected by hand or dipnet from 3 counties of arkansas and examined for coccidial parasites. a single frog (5%) was found to be passing oocysts of a new eimerian species. oocysts of eimeria menaensis n. sp. were ellipsoidal to subspheroidal with a bilayered wall and measured (l × w) 25.4 × 15.6 (23-27 × 13-17) µm, with a l/w ratio of 1.6. a micropyle was absent but an oocyst residuum and polar granule ... | 2014 | 25580093 |
| 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. | 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 n ... | 2008 | 18582957 |
| metamorphosis increases biotransformation of polychlorinated biphenyls: a comparative study of polychlorinated biphenyl metabolism in green frogs (rana clamitans) and leopard frogs (rana pipiens) at various life stages. | polychlorinated biphenyl (pcb) elimination rates were used to determine whether green frogs (rana clamitans) and leopard frogs (rana pipiens) at three life stages (tadpole, metamorph, and adult) were capable of metabolic biotransformation of pcbs. polychlorinated biphenyls were grouped according to their structural properties to determine whether congeners with specific structures were eliminated more rapidly than others, which would suggest the occurrence of metabolic biotransformation. for bot ... | 2006 | 17089721 |
| sediment tcdd-eqs and erod and mrod activities in ranid frogs from agricultural and nonagricultural sites in michigan (usa). | in vitro studies have demonstrated atrazine-mediated induction of 7-ethoxyresorufin o-deethylase (erod) activity. erod is an enzyme active in the metabolism of many compounds, including many xenobiotics. these studies have suggested that atrazine may affect reproductive function by altering steroid metabolism. the goal of this study was to determine whether relationships could be detected between measured atrazine concentrations in surface waters and the liver-somatic index (lsi) and erod and 7- ... | 2006 | 16788744 |
| determination of polychlorinated biphenyl and polycyclic aromatic hydrocarbon elimination rates in adult green and leopard frogs. | the purpose of the present study was to quantify elimination kinetics of polychlorinated biphenyls (pcbs) and polycyclic aromatic hydrocarbons (pahs) in adult green frogs (rana clamitans) and leopard frogs (rana pipiens). three experiments were conducted: pcb elimination rate constants were determined for both frog species, and pah elimination rate constants were determined for leopard frogs only. in green frogs, significant pcb elimination rate constants ranged from 0.013 to 0.04 d(-1) (time fo ... | 2006 | 16764482 |
| plasma steroid hormone concentrations, aromatase activities and gsi in ranid frogs collected from agricultural and non-agricultural sites in michigan (usa). | the triazine herbicide atrazine has been hypothesized to disrupt sexual development in frogs by up-regulating aromatase activity, resulting in greater estradiol (e2) concentrations and causing feminization in males. the goal of this study was to collect native ranid frogs from atrazine-exposed ponds and determine whether relationships exist between measured atrazine concentrations and the gonadosomatic index (gsi), plasma concentrations of testosterone (t), e2 or 11-ketotestosterone (kt), or wit ... | 2006 | 16427146 |
| atrazine concentrations, gonadal gross morphology and histology in ranid frogs collected in michigan agricultural areas. | the triazine herbicide atrazine has been suggested to be a potential disruptor of normal sexual development in male frogs. the goals of this study were to collect native ranid frogs from sites in agricultural and non-agricultural areas and determine whether hypothesised atrazine effects on the gonads could be observed at the gross morphological and histological levels. juvenile and adult green frogs (rana clamitans), bullfrogs (r. catesbeiana) and leopard frogs (r. pipiens) were collected in the ... | 2006 | 16300839 |
| field exposure of frog embryos and tadpoles along a pollution gradient in the fox river and green bay ecosystem in wisconsin, usa. | we raised embryos and tadpoles of green frogs (rana clamitans melanota) and leopard frogs (r. pipiens) in situ along a contamination gradient in the fox river/green bay ecosystem (wi, usa). differences in exposure were reflected by significant positive regressions between concentrations in sediment and in frogs of polychlorinated biphenyl (pcb) congeners and some heavy metals (cd, cr, and pb), which could have predictive value for estimating exposure of amphibians to contaminants in this ecosyst ... | 2005 | 15839570 |
| the pathogenicity, localization, and cyst structure of echinostomatid metacercariae (trematoda) infecting the kidneys of the frogs rana clamitans and rana pipiens. | light and scanning electron microscopy were used to examine the localization and pathogenicity of echinostomatid metacercariae infecting the kidneys of leopard frogs, rana pipiens, and green frogs, rana clamitans. cysts occurred predominantly in the ventrolateral renal cortex, and at least some were confined to the lumen of the bowman's capsules. each vermiform metacercarial body was enclosed by a spherical cyst wall that had a uniform thickness. the wall was composed of a homogeneous material c ... | 1990 | 2352071 |
| effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds. | some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. in particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. we documented colonization of eggs of three amphibian species, the wood frog (rana sylvatica), the green frog (rana clamitans), and the spotted salamander (ambystoma maculatum), by water molds in the field and examined the interactive effec ... | 2009 | 18976747 |
| effects of nitrate on embryos of three amphibian species. | embryos of three aquatic breeding amphibian species, ambystoma mexicanum, hyla chrysoscelis, and rana clamitans, were exposed to increasing levels (0, 5, 10, 30, 60, 100, 300, and 500 mg/l) of nitrate-n (no(3)-) in laboratory, static-renewal experiments. lethal effects were recorded from gosner stage 2 (h. chrysoscelis and r. clamitans) or harrison stage 2 (a. mexicanum) to time of hatching. date of hatching and length at hatching were also compared between treatments for a. mexicanum. no signif ... | 2008 | 18496633 |
| predicting community outcomes from pairwise interactions: integrating density- and trait-mediated effects. | understanding how species interactions shape the structure of ecological communities based on pairwise comparisons has been a difficult undertaking for ecologists because effects in reassembled communities can be different than simple density-mediated interactions would suggest. part of this complexity occurs because many species change their behavior and morphology with different predators and competitors and, thus, change their per-capita interaction rates (i.e. trait-mediated interactions). o ... | 2002 | 28547552 |
| environmental factors influencing calling in sympatric anurans. | anuran reproduction is influenced by various biotic and abiotic factors, of which temperature and rainfall are the best studied. here we examine the relationship between multiple abiotic environmental variables - specifically, air and water temperature, rainfall, barometric pressure, relative humidity and wind velocity - and the calling activity of five species (rana sylvatica, pseudacris crucifer, bufo americanus, rana clamitans, and rana catesbeiana) in an anuran community in new brunswick, ca ... | 2002 | 28466161 |
| dna replication in the amphibia. | autoradiographic techniques were used to measure rate of replication and length of the replication unit in cultured cells of scaphiopus couchi, bufo cognatus, rana clamitans, and triturus viridescens, having nuclear dna amounts in the ratio 1:4:7:39 respectively. the autoradiographic experiments were designed to show whether the larger amounts of nuclear dna are correlated with more rapid rates of synthesis and/or with longer replication units. -- the dna replication rate was 2.5 mu/minute (corr ... | 1975 | 125187 |
| role of sediments in modifying the toxicity of two roundup formulations to six species of larval anurans. | the role of sediment in modifying the toxicity of the original formulation of roundup® and roundup weathermax® was examined in aqueous laboratory tests. six species of anurans (bufo fowleri, hyla chrysoscelis, rana catesbeiana, rana clamitans, rana sphenocephala, and rana pipiens) were exposed at gosner stage 25 to concentrations of the 2 herbicide formulations in 96-h, static, nonrenewal experiments in the presence and absence of sediment. all species tested had lower median lethal concentratio ... | 2014 | 25132544 |
| comparative toxicity of two glyphosate formulations (original formulation of roundup® and roundup weathermax®) to six north american larval anurans. | the toxicity of two glyphosate formulations (the original formulation of roundup® and roundup weathermax®) to six species of north american larval anurans was evaluated by using 96-h static, nonrenewal aqueous exposures. the 96-h median lethal concentration values (lc50) ranged from 1.80 to 4.22 mg acid equivalent (ae)/l and 1.96 to 3.26 mg ae/l for the original formulation of roundup and roundup weathermax, respectively. judged by lc50 values, four species were more sensitive to roundup weather ... | 2011 | 21898567 |
| ultrastructural design of anuran muscles used for call production in relation to the thermal environment of a species. | i examined the aerobic trunk muscles, which are used for call production, of male frogs from species that breed in different thermal environments to test the hypothesis that cold-adapted frogs should have fewer capillaries per unit mitochondrial volume in oxidative muscles than warm-adapted frogs because of reduced mitochondrial function at low temperatures. the species of interest were the cold-temperate pseudacris crucifer and the warm-tropical hyla microcephala in the family hylidae, and the ... | 2001 | 11273806 |
| ameliorative effects of sodium chloride on acute copper toxicity among cope's gray tree frog (hyla chrysoscelis) and green frog (rana clamitans) embryos. | 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 inhibi ... | 2012 | 22278879 |
| effects of parentage on competitive ability and vulnerability to predation in hyla chrysoscelis tadpoles. | four sibships of hyla chrysoscelis larvae were used to examine the effects of parentage on mass at day 23 of growth and on vulnerability to predation. the h. chrysoscelis larvae were raised alone, in competition with rana clamitans larvae, and in competition with siblings. vulnerability to predation by adult notophthalmus viridescens dorsalis was evaluated for hyla that had been raised in competition with siblings. sibships differed in body mass and vulnerability to predation. competition with r ... | 1986 | 28310127 |
| effects of a common insecticide on wetland communities with varying quality of leaf litter inputs. | chemical contamination of aquatic systems often co-occurs with dramatic changes in surrounding terrestrial vegetation. plant leaf litter serves as a crucial resource input to many freshwater systems, and changes in litter species composition can alter the attributes of freshwater communities. however, little is known how variation in litter inputs interacts with chemical contaminants. we investigated the ecological effects resulting from changes in tree leaf litter inputs to freshwater communiti ... | 2017 | 28431762 |
| competitive stress can make the herbicide roundup® more deadly to larval amphibians. | toxicity assessments on nontarget organisms have largely been addressed using short-term, single-species laboratory experiments. although extremely helpful, these experiments inherently lack many pervasive ecological stressors found in nature. though a substantial challenge, incorporating these ecological stressors in contaminant studies would shed light on potential synergistic effects. for the world's leading herbicide, glyphosate, we know little about how natural stressors affect the toxicity ... | 2011 | 21038363 |
| foraging behaviour in tadpoles of the bronze frog rana temporalis: experimental evidence for the ideal free distribution. | the ability of bronze frog rana temporalis tadpoles (pure or mixed parental lines) to assess the profitability of food habitats and distribute themselves accordingly was tested experimentally using a rectangular choice tank with a non- continuous input design. food (boiled spinach) was placed at two opposite ends of the choice tank in a desired ratio (1 : 1, 1 : 2 or 1 : 4) to create habitat a and b. the tadpoles in gosner stage 28-33, pre-starved for 24 h, were introduced in an open ended mesh ... | 2004 | 15286417 |
| density-dependent growth and metamorphosis in the larval bronze frog rana temporalis is influenced by genetic relatedness of the cohort. | effects of density and kinship on growth and metamorphosis in tadpoles of rana temporalis were studied in a 2 4 factorial experiment. fifteen egg masses were collected from streams in the western ghat region of south india. the tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz. 15, 30, 60 and 120/5 l water. with an increase in density level from 15 to 120 tadpoles/5 l water, duration of the larval stage increased and fewer individuals metamorphosed i ... | 2003 | 12799495 |
| ichthyophonus-like infection in wild amphibians from québec, canada. | myositis associated with infection by ichthyophonus-like organisms was diagnosed in 35 of 260 (13%) wild amphibians collected in quebec, canada, from 1959 to 1964 (n = 30), and 1992 to 1999 (n = 230). infection was diagnosed in 17 green frogs rana clamitans, 9 wood frogs r. sylvatica, 4 red-spotted newts notophthalmus viridescens, 3 bullfrogs r. catesbeiana, 1 spring peeper pseudacris crucifer, and 1 pickerel frog r. palustris. the spring peeper and one of the bullfrogs were collected in 1964 fr ... | 2000 | 10843557 |
| competition and the distribution of spring peeper larvae. | studies of tadpole distributions have shown that despite overlapping affinities for semipermanent and permanent ponds, distributions of the spring peeper (pseudacris crucifer) and the green frog (rana clamitans) tend to be nonoverlapping. because spring peepers are believed to be poor competitors, i hypothesized that competition from green frog larvae limits the distribution of spring peeper larvae. i stocked field enclosures with a constant density of spring peeper larvae, and one of four densi ... | 1995 | 28306774 |
| transcriptome resources for the frogs lithobates clamitans and pseudacris regilla, emphasizing antimicrobial peptides and conserved loci for phylogenetics. | we developed genetic resources for two north american frogs, lithobates clamitans and pseudacris regilla, widespread native amphibians that are potential indicator species of environmental health. for both species, mrna from multiple tissues was sequenced using 454 technology. de novo assemblies with mira3 resulted in 50 238 contigs (n50 = 687 bp) and 48 213 contigs (n50 = 686 bp) for l. clamitans and p. regilla, respectively, after clustering with cd-hit-est and purging contigs below 200 bp. we ... | 2014 | 24028389 |
| the role of gamont entry into erythrocytes in the specificity of hepatozoon species (apicomplexa: adeleida) for their frog hosts. | 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 intraerythroc ... | 2013 | 23829695 |
| mercury concentrations in wetlands associated with coal-fired power plants. | there have been contradictory reports of the relative proportion of mercury from coal-fired power plants that deposits locally. our objective was to determine any local effect of coal-fired power plants on total mercury concentrations in wetland sediment and tadpole samples. four power plants and 45 wetlands were selected for study. total mercury concentrations were determined in 75 sediment samples (range: 8-82 ng/g dry weight) and 100 bullfrog (lithobates catesbeiana) and green frog (lithobate ... | 2010 | 19771512 |
| incongruence in the pattern and timing of intra-specific diversification in bronze frogs and bullfrogs (ranidae). | we compare patterns of lineage divergence in mitochondrial dna (mtdna) sequences of two protein-encoding mitochondrial genes (cyt b and nd2) in two ecologically similar, co-distributed, and closely related ranid frogs (rana clamitans and rana catesbeiana), that are geographically widespread, and frequently syntopic. we identified three lineages in r. clamitans, separated by 0.5% to 2.1% net corrected sequence divergence, comparable to two r. catesbeiana lineages separated by 0.6%. the geographic ... | 2008 | 18625326 |
| peptidomic analysis of skin secretions from rana heckscheri and rana okaloosae provides insight into phylogenetic relationships among frogs of the aquarana species group. | the members of the aquarana (or rana catesbeiana species group) form a monophyletic group comprising seven species: r. catesbeiana, rana clamitans, rana grylio, rana virgatipes, rana septentrionalis, rana heckscheri and rana okaloosae. previous work has led to structural characterization of the antimicrobial peptides present in electrically-stimulated skin secretions from the first five species listed and this study presents the primary structures of orthologs from the river frog r. heckscheri a ... | 2007 | 17005262 |
| limb malformations and abnormal sex hormone concentrations in frogs. | 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 ... | 2000 | 11102301 |
| ultrastructural, biochemical and biophysical properties of an erythrocytic virus of frogs from ontario, canada. | frog erythrocytic virus (fev), one of the largest icosahedral viruses, is enveloped, measures up to 450 nm in diameter, and contains double stranded dna. the virus is found in the cytoplasm of erythrocytes of rana catesbeiana, rana septentrionalis, and rana clamitans from algonquin park, ontario (canada). acidophilic inclusions in infected erythrocytes stained with giemsa's stain correspond to viroplasms from which fev buds and forms aggregates of virus particles as seen in the electron microsco ... | 1989 | 2810549 |
| genetic analysis of developmental arrest in an amphibian hybrid (rana catesbeiana, rana clamitans). | | 1981 | 6970150 |
| fertilization of green frog (rana clamitans) eggs in their native jelly by bullfrog (rana catesbeiana) sperm. | fertilization of r. clamitans eggs in their native jelly occurred when inseminated with high concentrations of r. catesbeiana sperm. contrary to previous evidence, the block to cross-fertilization of the r. clamitans egg is not complete. this raises the possibility that r. clamitans x r. catesbeiana hybrids may form in nature. | 1975 | 1080794 |
| viable amphibian hybrids produced by circumventing a block to cross-fertilization(rana clamitans female x rana catesbeiana male). | eggs of rana clamitans in their own jelly coat are not fertilized by sperm of other species. when the eggs were surrounded by jelly from another species, they were fertilized by r. catesbeiana and r. septentrionalis sperm. the hybrid nature of the resulting embryos was confirmed by detection of paternal enzyme forms. the r. clamitans female times r. septentrionalis male embryos arrested by the tailbud stage. the r. clamitans female times r. catesbeiana male embryos developed into viable tadpoles ... | 1975 | 806650 |
| behavioral reflexes in rana catesbeiana and rana clamitans with large skin grafts. | | 1970 | 4908573 |
| the origin and ecological function of an ion inducing anti-predator behavior in lithobates tadpoles. | in aquatic environments, chemical cues are believed to be associated with prey response to predation risk, yet few basic cue compositions are known despite the pronounced ecological and evolutionary significance of such cues. previous work indicated that negatively-charged ions of m/z 501 are possibly a kairomone that induces anti-predator responses in amphibian tadpoles. however, work described here confirms that this specific ion species m/z 501.2886 is produced by injured tadpoles, exhibits i ... | 0 | 29336000 |
| the distribution of echinostome parasites in ponds and implications for larval anuran survival. | parasites can influence host population dynamics, community composition and evolution. prediction of these effects, however, requires an understanding of the influence of ecological context on parasite distributions and the consequences of infection for host fitness. we address these issues with an amphibian - trematode (digenea: echinostomatidae) host-parasite system. we initially performed a field survey of trematode infection in first (snail) and second (larval green frog, rana clamitans) int ... | 2017 | 28073389 |