| ranavirus infection of free-ranging and captive box turtles and tortoises in the united states. | iridoviruses of the genus ranavirus are well known for causing mass mortality events of fish and amphibians with sporadic reports of infection in reptiles. this article describes five instances of ranavirus infection in chelonians between 2003 and 2005 in georgia, florida, new york, and pennsylvania, usa. affected species included captive burmese star tortoises (geochelone platynota), a free-ranging gopher tortoise (gopherus polyphemus), free-ranging eastern box turtles (terrapene carolina carol ... | 2008 | 18957641 |
| physiological effects and bioconcentration of triclosan on amphibian larvae. | we examined the acute effects of triclosan (tcs) exposure, a common antimicrobial found as a contaminant in the field, on survival and physiology of amphibian larvae. lc50 values were determined after 96h for north american larval species: acris crepitans blanchardii, bufo woodhousii woodhousii, rana sphenocephala, and for a developmental model: xenopus laevis. amphibian larvae were most sensitive to tcs exposure during early development based upon 96-h lc50 values. heart rates for x. laevis and ... | 2010 | 20417311 |
| the fungicide chlorothalonil is nonlinearly associated with corticosterone levels, immunity, and mortality in amphibians. | background: contaminants have been implicated in declines of amphibians, a taxon with vital systems similar to those of humans. however, many chemicals have not been thoroughly tested on amphibians or do not directly kill them.objective: our goal in this study was to quantify amphibian responses to chlorothalonil, the most commonly used synthetic fungicide in the united states.methods: we reared rana sphenocephala (southern leopard frog) and osteopilus septentrionalis (cuban treefrog) in outdoor ... | 2011 | 21463979 |
| unlikely remedy: fungicide clears infection from pathogenic fungus in larval southern leopard frogs (lithobates sphenocephalus). | 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 ... | 2012 | 22912890 |
| the effects of a fungicide and chytrid fungus on anuran larvae in aquatic mesocosms. | the amphibian disease chytridiomycosis, caused by the pathogenic fungus batrachochytrium dendrobatidis (bd), has been linked to significant amphibian declines over the past three decades. the most severe effects of the pathogen have been primarily observed in relatively pristine areas that are not affected by many anthropogenic factors.one hypothesis concerning improved amphibian persistence with bd in disturbed landscapes is that contaminants may abate the effects of bd on amphibians. recent la ... | 2015 | 25913318 |
| patterns of amphibian infection prevalence across wetlands on the savannah river site, south carolina, usa. | amphibian diseases, such as chytridiomycosis caused by batrachochytrium dendrobatidis (bd) and ranaviral disease caused by ranaviruses, are often linked to global amphibian population declines, yet the ecological dynamics of both pathogens are poorly understood. the goal of our study was to determine the baseline prevalence, pathogen loads, and co-infection rate of bd and ranavirus across the savannah river site (srs) in south carolina, usa, a region with rich amphibian diversity and a history o ... | 2016 | 27596855 |
| dietary protein restriction impairs growth, immunity, and disease resistance in southern leopard frog tadpoles. | the immune system is a necessary, but potentially costly, defense against infectious diseases. when nutrition is limited, immune activity may consume a significant amount of an organism's energy budget. levels of dietary protein affect immune system function; high levels can enhance disease resistance. we exposed southern leopard frog [lithobates sphenocephalus (=rana sphenocephala)] tadpoles to high and low protein diets crossed with the presence or absence of the pathogenic amphibian chytrid f ... | 2011 | 22038058 |
| suitability of golf course ponds for amphibian metamorphosis when bullfrogs are removed. | managing areas designed for human recreation so that they are compatible with natural amphibian populations can reduce the negative impacts of habitat destruction. we examined the potential for amphibians to complete larval development in golf course ponds in the presence or absence of overwintered bullfrog tadpoles (rana catesbeiana), which are frequently found in permanent, human-made ponds. we reared larval american toads (bufo americanus), southern leopard frogs (r. sphenocephala), and spott ... | 2008 | 18254862 |
| prevalence of batrachochytrium dendrobatidis in american bullfrog and southern leopard frog larvae from wetlands on the savannah river site, south carolina. | batrachochytrium dendrobatidis, an aquatic fungus, has been linked to recent amphibian population declines. few surveys have assessed b. dendrobatidis infections in areas where the disease is suggested to be less virulent and population declines have not been observed, such as southeastern north america. although adult rana catesbeiana and rana sphenocephala from the savannah river site, south carolina collected in 1979 and 1982 were identified as having b. dendrobatidis, it is unknown whether t ... | 2007 | 17699083 |
| multiple stressors in amphibian communities: effects of chemical contamination, bullfrogs, and fish. | a leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. we examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. we exposed larvae of american toads (bufo americanus), southern leopard frogs (rana sphenocephala), and spotted salamanders (ambystoma maculatum) to overwintered bullfrog tadpoles (r. catesbeiana), bluegill sunfish (lepomis macrochirus), ... | 2007 | 17479852 |
| metamorphosis of two amphibian species after chronic cadmium exposure in outdoor aquatic mesocosms. | amphibian larvae at contaminated sites may experience an alteration of metamorphic traits and survival compared to amphibians in uncontaminated conditions. effects of chronic cadmium (cd) exposure on the metamorphosis of american toads (bufo americanus) and southern leopard frogs (rana sphenocephala) were determined. the two species were reared separately from shortly after hatching through metamorphosis in outdoor mesocosms (1,325-l polyethylene cattle tanks) that simulated natural ponds and en ... | 2005 | 16152972 |
| peptides with antimicrobial activity of the brevinin-1 family isolated from skin secretions of the southern leopard frog, rana sphenocephala. | three peptides with growth-inhibitory activity towards the gram-negative bacterium eschericia coli were isolated from electrically stimulated secretions from the skin of the southern leopard frog, rana sphenocephala. structural characterization demonstrated that the peptides [brevinin-1sa, minimum inhibitory concentration (mic) = 55 microm; brevinin-1sb, mic = 17 microm; brevinin-1sc, mic = 14 microm] represent new members of the brevinin-1 family of antimicrobial peptides, previously isolated f ... | 1999 | 10604597 |
| granulomatous myositis associated with a novel alveolate pathogen in an adult southern leopard frog (lithobates sphenocephalus). | since 1999, infections with an incompletely characterized alveolate protozoan variously reported as a dermocystidium-like organism, a perkinsus-like agent, and dermomycoides sp. have been associated with mortality events in tadpoles of ranid frogs from the usa. however, disease or mortality events due to this organism have not been described in post-metamorphic animals. we describe infection with a morphologically similar protozoan presenting itself as a leg mass in a free-ranging adult southern ... | 2012 | 23269391 |
| herpetofaunal community change in multiple habitats after fifteen years in a southwest florida preserve, usa. | herpetofaunal declines have been documented globally, and southern florida, usa, is an especially vulnerable region because of high impacts from hydrological perturbations and nonindigenous species. to assess the extent of recent change in herpetofauna community composition, we established a baseline inventory during 1995-97 at a managed preserve in a habitat rich area of southwest florida, and repeated our sampling methods fifteen years later (2010-11). nine drift fence arrays were placed in fo ... | 2015 | 26016475 |
| the effects of ultraviolet-b radiation on the toxicity of fire-fighting chemicals. | the interactive effects of ultraviolet (uv) and fire-retardant chemicals were evaluated by exposing rainbow trout (oncorhyncus mykiss) juveniles and tadpoles of southern leopard frogs (rana sphenocephala) to six fire-retardant formulations with and without sodium ferrocyanide (yellow prussiate of soda [yps]) and to yps alone under three simulated uv light treatments. yellow prussiate of soda is used as a corrosion inhibitor in some of the fire-retardant chemical formulations. the underwater uv i ... | 2003 | 12836977 |
| variation in somatic and ovarian development: predicting susceptibility of amphibians to estrogenic contaminants. | although amphibian sex determination is genetic, it can be manipulated by exogenous hormone exposure during sexual differentiation. the timing of sexual differentiation varies among anuran amphibians such that species may or may not be a tadpole during this period, and therefore, may or may not be exposed to aquatic contaminants. estrogenic contamination is present in amphibian habitats worldwide. we examined three species with varying somatic and ovarian developmental rates to assess their susc ... | 2008 | 18420201 |
| intersex gonads in frogs: understanding the time course of natural development and role of endocrine disruptors. | the paucity of data on sexual development of anuran amphibians has played an important role in the recent controversy over atrazine exposure. although some studies have demonstrated the presence of abnormal gonads in control treatments, others have not, leading to varying interpretations of the effects of atrazine exposure on sexual development. however, the timing of development varies among anuran amphibians such that, at any snapshot in time, different species may exhibit different stages of ... | 2010 | 19588491 |
| amphibian lipid levels at metamorphosis correlate to post-metamorphic terrestrial survival. | in organisms that have complex life cycles, factors in the larval environment may affect both larval and adult traits. for amphibians, the postmetamorphic transition from the aquatic environment to terrestrial habitat may be a period of high juvenile mortality. we hypothesized that lipid stores at metamorphosis may affect an animal's success during this critical transition period. we examined variation in total lipid levels among years and sites in recently metamorphosed individuals of two pond- ... | 2007 | 17530291 |
| tadpole size, cholinesterase activity, and swim speed in four frog species after exposure to sub-lethal concentrations of chlorpyrifos. | while physiological biomarkers exist to verify exposure of amphibians in natural populations to agricultural chemicals, the ecological relevance of changes in these parameters is often difficult to determine. we compare the relationship between tadpole cholinesterase (che; a common enzymatic biomarker of exposure to op pesticides) and measures of size and swim speed in four native north american species of anurans (hyla chrysoscelis, rana sphenocephala, acris crepitans, and gastrophryne olivacea ... | 2008 | 18448174 |
| host use and seasonality of culex (melanoconion) iolambdis (diptera: culicidae) from eastern florida, usa. | culex (melanoconion) iolambdis (dyar, 1918) is a mosquito (diptera: culicidae) species found throughout much of tropical america, including southern florida. relatively few reports are available regarding the ecology of cx. iolambdis, despite its widespread distribution and putative involvement in transmission of venezuelan equine encephalitis virus. to quantify habitat and host utilization, adults of cx. iolambdis were sampled from resting shelters at a field site in vero beach, florida, over a ... | 2016 | 27712940 |
| effects of dietary vanadium on growth and lipid storage in a larval anuran: results from studies employing ad libitum and rationed feeding. | vanadium (v) exerts a variety of effects related to metabolic function in vertebrates, including modifying glycolytic pathways and lipid metabolism. however, little is known about toxicity of v to wildlife in natural systems. we conducted parallel, independent studies to evaluate the effect of dietary exposure to vanadium on survival, metabolism, growth, and lipid storage of larval leopard frogs (rana sphenocephala). in one study ("ad lib") larvae were fed unlimited food and in the other ("ratio ... | 2009 | 18602705 |
| quantifying larval trematode infections in hosts: a comparison of method validity and implications for infection success. | accurately estimating parasite transmission success and subsequent infection load has important ramifications for a wide range of disease-related questions and research disciplines. recent interest in the role of parasites in amphibian population declines and deformities, for instance, has prompted increased interest in approaches to quantify infection and pathology. here, we introduce a novel method of fluorescently labeling trematode cercariae and optimize its application to interactions betwe ... | 2015 | 25888244 |
| co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in florida, usa. | a multispecies amphibian larval mortality event, primarily affecting american bullfrogs lithobates catesbeianus, was investigated during april 2011 at the mike roess gold head branch state park, clay county, florida, usa. freshly dead and moribund tadpoles had hemorrhagic lesions around the vent and on the ventral body surface, with some exhibiting a swollen abdomen. bullfrogs (100%), southern leopard frogs l. sphenocephalus (33.3%), and gopher frogs l. capito (100%) were infected by alveolate p ... | 2013 | 23872853 |
| daphnia predation on the amphibian chytrid fungus and its impacts on disease risk in tadpoles. | direct predation upon parasites has the potential to reduce infection in host populations. for example, the fungal parasite of amphibians, batrachochytrium dendrobatidis (bd), is commonly transmitted through a free-swimming zoospore stage that may be vulnerable to predation. potential predators of bd include freshwater zooplankton that graze on organisms in the water column. we tested the ability of two species of freshwater crustacean (daphnia magna and d. dentifera) to consume bd and to reduce ... | 2013 | 24324864 |
| evaluation of amphotericin b and chloramphenicol as alternative drugs for treatment of chytridiomycosis and their impacts on innate skin defenses. | chytridiomycosis, an amphibian skin disease caused by the emerging fungal pathogen batrachochytrium dendrobatidis, has been implicated in catastrophic global amphibian declines. the result is an alarming decrease in amphibian diversity that is a great concern for the scientific community. clinical trials testing potential antifungal drugs are needed to identify alternative treatments for amphibians infected with this pathogen. in this study, we quantified the mics of chloramphenicol (800 μg/ml), ... | 2014 | 24771024 |
| development of antimicrobial peptide defenses of southern leopard frogs, rana sphenocephala, against the pathogenic chytrid fungus, batrachochytrium dendrobatidis. | amphibian species face the growing threat of extinction due to the emerging fungal pathogen batrachochytrium dendrobatidis, which causes the disease chytridiomycosis. antimicrobial peptides (amps) produced in granular glands of the skin are an important defense against this pathogen. little is known about the ontogeny of amp production or the impact of amps on potentially beneficial symbiotic skin bacteria. we show here that rana (lithobates) sphenocephala produces a mixture of four amps with ac ... | 2015 | 25218643 |
| batrachochytrium dendrobatidis exposure effects on foraging efficiencies and body size in anuran tadpoles. | chytridiomycosis, the amphibian disease caused by the pathogenic fungus batrachochytrium dendrobatidis (bd), is fatal to adults of many species. bd is largely sublethal to amphibian larvae; however, it is known to reduce larval (i.e. tadpole) growth rates, with possible long-term effects on population dynamics and fitness. we conducted an experiment to test how bd altered southern leopard frog lithobates sphenocephalus tadpole mouthpart damage, percentage of food ingested, and subsequent body si ... | 2015 | 25590774 |
| the deal with diel: temperature fluctuations, asymmetrical warming, and ubiquitous metals contaminants. | climate projections over the next century include disproportionately warmer nighttime temperatures ("asymmetrical warming"). cool nighttime temperatures lower metabolic rates of aquatic ectotherms. in contaminated waters, areas with cool nights may provide thermal refugia from high rates of daytime contaminant uptake. we exposed cope's gray tree frogs (hyla chrysoscelis), southern leopard frogs (lithobates sphenocephalus), and spotted salamanders (ambystoma maculatum) to five concentrations of a ... | 2015 | 26142755 |
| temporal occurrence and community structure of helminth parasites in southern leopard frogs, rana sphenocephala, from north central oklahoma. | 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 helmin ... | 2015 | 25566773 |
| joint effects of resources and amphibians on pond ecosystems. | primary production can be controlled through bottom-up (e.g., resources) or top-down (e.g., predators) constraints. two key bottom-up resources in small aquatic systems are light and nutrients, and forest canopy cover heavily influences these factors, whereas amphibian and invertebrate colonizers exert top-down pressure as grazers and predators. we designed our experiment to specifically manipulate two different top-down and bottom-up factors. we manipulated resources by altering light (low/high ... | 2017 | 27718066 |
| do parasitic trematode cercariae demonstrate a preference for susceptible host species? | many parasites are motile and exhibit behavioural preferences for certain host species. because hosts can vary in their susceptibility to infections, parasites might benefit from preferentially detecting and infecting the most susceptible host, but this mechanistic hypothesis for host-choice has rarely been tested. we evaluated whether cercariae (larval trematode parasites) prefer the most susceptible host species by simultaneously presenting cercariae with four species of tadpole hosts. cercari ... | 2012 | 23272084 |
| integrating copper toxicity and climate change to understand extinction risk to two species of pond-breeding anurans. | chemical contamination is often suggested as an important contributing factor to amphibian population declines, but direct links are rarely reported. population modeling provides a quantitative method to integrate toxicity data with demographic data to understand the long-term effects of contaminants on population persistence. in this study we use laboratory-derived embryo and larval toxicity data for two anuran species to investigate the potential for toxicity to contribute to population declin ... | 2016 | 27755699 |
| reciprocal subsidies in ponds: does leaf input increase frog biomass export? | reciprocal subsidies occur when ecosystems are paired, both importing and exporting resources to each other. the input of subsidies increases reciprocal subsidy export, but it is unclear how this changes with other important factors, such as ambient resources. we provide a conceptual framework for reciprocal subsidies and empirical data testing this framework using a pond-forest system in missouri, usa. our experiment used in situ pond mesocosms and three species of anurans: wood frogs, american ... | 2012 | 22622875 |
| effects of chronic copper exposure on development and survival in the southern leopard frog (lithobates [rana] sphenocephalus). | exposure to environmental contaminants contributes to the global decline of amphibian populations. the impacts of organic contaminants on amphibians are well documented. however, substantially less is known concerning the potential effects of metals on amphibian populations. copper (cu) is an essential element, but it can be toxic at concentrations only slightly higher than the normal physiological range. the present study examines the effects of chronic cu exposure on embryos and larvae of sout ... | 2012 | 22511547 |
| phylogeographic analyses of the southern leopard frog: the impact of geography and climate on the distribution of genetic lineages vs. subspecies. | the southeastern united states is a major phylogeographic break hotspot for amphibians, but the processes underlying this hotspot remain to be explicitly tested. we test the correlation of genetic lineages with subspecies breaks in the southeastern united states and the association of such breaks with climate, using rana sphenocephala as a case study, and place our results in the broader context of the alabama-appalachian suture zone (al-appalachian sz). we use genetic and ecological methods to ... | 2011 | 22066968 |
| soft-tissue mineralization of bullfrog larvae (rana catesbeiana) at a wastewater treatment facility. | bullfrog tadpoles (rana catesbeiana) from a wastewater treatment facility were identified with severe lesions consisting of large, up to 1-cm in diameter, mineralized nodules protruding from the tail or gular region. sectioning of formalin-fixed specimens revealed more extensive mineralization involving the vertebrae or muscles of the head and tail. nodules examined microscopically were not associated with parasitic or infectious agents. large nodules consisted of mineralized aggregates surround ... | 2010 | 20622246 |
| carryover effects in amphibians: are characteristics of the larval habitat needed to predict juvenile survival? | carryover effects occur when experiences early in life affect an individual's performance at a later stage. many studies have shown carryover effects to be important for future performance. however, it is currently unclear whether variation in later environments could overwhelm factors from an earlier life stage. we were interested in whether similar patterns would emerge under the same experimental design with similar taxa. to examine this, we implemented a four-way factorial experimental desig ... | 2013 | 24147414 |
| how does a change in labial tooth row number affect feeding kinematics and foraging performance of a ranid tadpole (lithobates sphenocephalus)? | recent studies have explored feeding kinematics in tadpoles with intact labial teeth; however, it is unknown how missing teeth impacts foraging. we explored the impact of missing labial teeth on the feeding mechanics and foraging performance of southern leopard frog (lithobates sphenocephalus [= rana sphenocephala]) tadpoles by controlling the pattern of labial tooth loss; that is, by surgically removing one row of labial teeth. we then used high-speed (500 frames/second) videography to test the ... | 2010 | 20413792 |
| habitat predictors of genetic diversity for two sympatric wetland-breeding amphibian species. | population genetic diversity is widely accepted as important to the conservation and management of wildlife. however, habitat features may differentially affect evolutionary processes that facilitate population genetic diversity among sympatric species. we measured genetic diversity for two pond-breeding amphibian species (dwarf salamanders, eurycea quadridigitata; and southern leopard frogs, lithobates sphenocephalus) to understand how habitat characteristics and spatial scale affect genetic di ... | 2017 | 28861231 |
| exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in rana sphenocephala. | 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 larv ... | 2009 | 18627796 |
| the influence of temperature and spatial distribution on the susceptibility of southern leopard frog eggs to disease. | since host defenses to infectious disease are often costly, one would expect hosts to use their defenses only when the threat of infection is high. southern leopard frogs (rana sphenocephala) at ellenton bay in south carolina (usa) have an extended breeding season and their eggs are exposed to a wide range of temperatures depending on the time of year when they are laid. adults aggregate their egg masses in cold temperatures, but separate them in warm temperatures. the spatial aggregation of egg ... | 2008 | 18368423 |
| alteration of larval development and metamorphosis by nitrate and perchlorate in southern leopard frogs (rana sphenocephala). | amphibians are sensitive to a great variety of agrochemicals. nitrate compounds are commonly applied as fertilizers, whereas perchlorate salts occur as by-products of the military industry and in some nitrate fertilizers. both compounds are highly soluble and can easily diffuse between ground and surface water, thus potentially affecting amphibians. nitrate reduces embryonic and larval survival and development, whereas perchlorate has a well-known goitrogenic effect and inhibits metamorphosis. w ... | 2007 | 17657452 |
| a new species of leopard frog (anura: ranidae) from the urban northeastern us. | 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, ... | 2012 | 22321689 |
| selenium:mercury molar ratios in bullfrog and leopard frog tadpoles from the northeastern united states. | vertebrates experience adverse effects from methylmercury, largely obtained through their food. selenium has the potential to reduce the toxic effects of methylmercury (and vice versa). in this paper, we examine the selenium:mercury molar ratios in tadpoles (lithobates sphenocephalus, lithobates catesbeianus (formerly rana), and a newly documented leopard frog species currently referred to as r. sp. nov.) and fully formed leopard frog metamorphs. there were no significant differences in metal le ... | 2014 | 24585386 |
| the acute thermal respiratory response is unique among species in a guild of larval anuran amphibians-implications for energy economy in a warmer future. | climate change is bringing about increased temperatures of amphibian habitats throughout the world, where ectothermic larvae will experience elevated respiratory (metabolic) energy demands. we compared the acute, thermal respiratory response ("trr") of four species of sympatric larval amphibians (lithobates sphenocephalus, l. catesbeianus, scaphiopus holbrookii, and hyla chrysoscelis) to determine species-specific differences in the rate at which metabolic energy requirements increase with tempe ... | 0 | 29128771 |
| adverse effects of ecologically relevant dietary mercury exposure in southern leopard frog (rana sphenocephala) larvae. | southern leopard frog (rana sphenocephala) larvae were exposed to experimental diets supplemented with aufwuchs from control and mercury-enriched mesocosms combined in proportions intended to mimic mercury concentrations and speciation in aufwuchs observed from aquatic systems contaminated by atmospheric deposition. observations on rates of mortality, malformation, and larval growth and development were made for 254 d. increased incidence of mortality, malformation, and changes in growth and dev ... | 2004 | 15648772 |
| dietary mercury exposure and bioaccumulation in southern leopard frog (rana sphenocephala) larvae. | aufwuchs was collected from three reservoirs, a constructed wetland used for groundwater treatment, and mercury (hg)-enriched mesocosms to examine the relationship between inorganic hg and methylmercury concentrations in the diet of tadpoles. four diets were then formulated with hg-enriched aufwuchs to concentrations that bracketed those of hg observed in aufwuchs from the field and reported in the literature from sites contaminated by atmospheric deposition. the diets were fed to southern leopa ... | 2004 | 15648771 |
| metal levels in southern leopard frogs from the savannah river site: location and body compartment effects. | 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 ... | 2001 | 11437462 |
| social influences on androgen levels in the southern leopard frog, rana sphenocephala. | social cues play an important role in modulating neuroendocrine and hormonal states in many vertebrates. social cues in the form of conspecific advertisement calls have been demonstrated to modulate plasma androgen levels in male rana sphenocephala, the southern leopard frog. male r. sphenocephala were captured and brought to the laboratory for testing. animals were exposed to one of two acoustical environments: a recording of an active conspecific breeding chorus or a recording of the same chor ... | 2001 | 11161771 |
| long-term effects of pesticide exposure at various life stages of the southern leopard frog (rana sphenocephala). | 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 thr ... | 2000 | 10790507 |
| cryptic diversity in metropolis: confirmation of a new leopard frog species (anura: ranidae) from new york city and surrounding atlantic coast regions. | 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 ... | 2014 | 25354068 |
| mouthparts of southern leopard frog, lithobates sphenocephalus, tadpoles not affected by exposure to a formulation of glyphosate. | this study evaluated the impacts of roundup® on tadpole mouthpart damage as a mechanism for reduced growth and developmental rates in lithobates sphenocephalus (southern leopard frog) tadpoles. we did not find evidence that roundup(®) damages larval mouthparts, nor was there a significant relationship between mouthpart damage and either body condition or developmental rate. however, the highest concentration of roundup® significantly stunted development compared to all other treatments. although ... | 2013 | 24068468 |
| a novel sample preparation method that enables nucleic acid analysis from ultrathin sections. | the ability to isolate and perform nucleic acid analyses of individual cells is critical to studying the development of various cell types and structures. we present a novel biological sample preparation method developed for laser capture microdissection-assisted nucleic acid analysis of ultrathin cell/tissue sections. we used cells of the mitotic bed of the tadpole teeth of lithobates sphenocephalus (southern leopard frog). cells from the mitotic beds at the base of the developing teeth series ... | 2013 | 23518143 |
| prostaglandin f2 alpha inhibits acidification in h(+)-secreting epithelia. | the role of prostaglandins in the regulation of acidification mechanisms in h(+)-secreting epithelia has been investigated in the abdominal skin of the southern leopard frog, rana pipiens. exogenous administration of prostaglandin (pg) e2 and pgf1 alpha (10(-7) m) to the serosal media of paired skins mounted in modified ussing chambers showed no significant alteration on h+ excretion rates. pgf2 alpha exhibited a dose-dependent inhibition of acidification in both the mucosal and serosal media of ... | 1990 | 2319476 |
| adaptive changes of h+ secreting cells in the epidermis of the leopard frog rana pipiens. | 1. mitochondria-rich (mr) cells in the integument of the southern leopard frog, rana pipiens, berlandieri, were stained with agno3 under a variety of environmental and metabolic treatment conditions known to increase h+ excretion rates across the skin. in this tissue agno3 proved to be a good stain for discriminating the mr cell populations from the granular cells. 2. high salinity adapted southern frogs showed no change in the mr cell population. the inability of the mr cell number to significa ... | 1990 | 1980436 |
| role of sodium on h+ excretion in the integument of the leopard frog rana pipiens. | 1. the northern leopard frog, rana pipiens, pipiens, in contrast to the southern leopard frog, rana pipiens, berlandieri, did not demonstrate any significant h+ excretion across its integument even during a challenge of chronic metabolic acidosis. likewise, no increase in the number of h+ secreting mitochondria-rich cells were observed in the northern frogs. 2. under normal acid-base conditions in the southern frogs, h+ excretion was found to be dependent on mucosal sodium concentrations, wherea ... | 1988 | 2904333 |
| effects of lead-contaminated sediment on rana sphenocephala tadpoles. | 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 microg/l. tadpoles exposed to lead concentrations in sed ... | 2006 | 16823520 |
| 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 |
| dietary mercury exposure and bioaccumulation in amphibian larvae inhabiting carolina bay wetlands. | inorganic mercury and methylmercury concentrations were measured both in guts and remaining carcasses of southern leopard frog (rana sphenocephala) larvae from 10 carolina bay wetlands in south carolina, usa. significant variation among bays in methylmercury and inorganic mercury concentrations existed both in guts and carcasses. there was a moderate negative correlation between dissolved organic carbon concentration in bays and mean inorganic mercury concentrations in guts. there was also a wea ... | 2005 | 15734584 |
| distribution and reproductive plasticity of gyrinicola batrachiensis (oxyuroidea: pharyngodonidae) in tadpoles of five anuran species. | previous studies on gyrinicola batrachiensis indicate that these pinworms have distinct reproductive strategies dependent on the development time to metamorphosis of their anuran tadpole hosts. in tadpoles of amphibian species with short developmental periods (a few weeks), female nematodes reproduce parthenogenetically, and only produce thick-shelled eggs used as transmission agents from tadpole to tadpole. in contrast, nematodes in tadpoles with longer larval developmental periods (months to y ... | 2017 | 29280071 |
| remarkable amphibian biomass and abundance in an isolated wetland: implications for wetland conservation. | despite the continuing loss of wetland habitats and associated declines in amphibian populations, attempts to translate wetland losses into measurable losses to ecosystems have been lacking. we estimated the potential productivity from the amphibian community that would be compromised by the loss of a single isolated wetland that has been protected from most industrial, agricultural, and urban impacts for the past 54 years. we used a continuous drift fence at ellenton bay, a 10-ha freshwater wet ... | 2006 | 17002763 |
| species- and stage-specific differences in trace element tissue concentrations in amphibians: implications for the disposal of coal-combustion wastes. | information on species- and stage-specific patterns of contaminant accumulation is generally lacking for amphibians, yet such information could provide valuable knowledge on how amphibians interact with contaminants. we assessed concentrations of as, cd, cu, ni, pb, se, sr, and zn in whole bodies of larval, recently metamorphosed, and adult life stages in bufo terrestris and rana sphenocephala from a site that currently receives coal combustion waste (ccw) discharge, a site where ccw was formerl ... | 2005 | 15840543 |
| draft genome sequence of xenophilus sp., a novel bacterium isolated from the skin of a southern leopard frog (rana sphenocephala) in florida, usa. | we report here the draft genome sequence of a novel xenophilus species cultured from the skin of a southern leopard frog (rana sphenocephala). compared to previously sequenced bacterial genomes, our novel isolate showed the most significant homology with xenophilus azovorans the assembled genome is 3,978,285 bp, with 3,704 predicted genes and one predicted plasmid. | 2017 | 28963224 |
| reproductive plasticity in the nematode gyrinicola batrachiensis: does an intermediate reproductive strategy exist in sexually reproducing, didelphic pinworms? | phenotypic plasticity is a process in which multiple phenotypes arise from 1 genotype because of environmental selection pressures. gyrinicola batrachiensis has a heterogeneous reproductive strategy such that females reproduce either via parthogenesis with thick-shelled eggs in a single uterus or sexual reproduction with thick- and thin-shelled eggs in separate uterine horns. no evidence exists that strains of g. batrachiensis are able to switch between parthenogenetic and sexual reproduction. t ... | 2017 | 28732178 |
| mismatched anti-predator behavioral responses in predator-naïve larval anurans. | organisms are adept at altering behaviors to balance the tradeoff between foraging and predation risk in spatially and temporally shifting predator environments. in order to optimize this tradeoff, prey need to be able to display an appropriate response based on degree of predation risk. to be most beneficial in the earliest life stages in which many prey are vulnerable to predation, innate anti-predator responses should scale to match the risk imposed by predators until learned anti-predator re ... | 2015 | 26664805 |
| increased larval density induces accelerated metamorphosis independently of growth rate in the frog rana sphenocephala. | we grew larval rana sphenocephala at different densities but maintained equal mean growth rates among density treatments (via equal per capita food levels) to test the hypothesis that larval density can influence metamorphic timing independently of larval growth rate. tadpoles at high density metamorphosed earlier than tadpoles at low density despite growing at similar rates. food reductions did not accelerate metamorphosis. these results support the hypothesis that density can be a sufficient c ... | 2009 | 29276310 |
| cholinesterase activity and behavior in chlorpyrifos-exposed rana sphenocephala tadpoles. | recent studies have found a correlation between organophosphate (op) pesticide exposure and declines in amphibian populations. we evaluated the hypothesis that this relationship is driven by behavioral changes in developing larvae. specifically, we examined how exposure to a common op pesticide, chlorpyrifos, influenced cholinesterase (che) activity, mass, and swim speed in rana sphenocephala tadpoles. we also determined how the presence of natural pond sediments in exposure chambers influenced ... | 2006 | 16986800 |
| acute toxicities of toxaphene and endrin to larvae of seven species of amphibians. | seven species of amphibian larvae were exposed to toxaphene and endrin in a continuous-flow dosing system to determine differences in sensitivity to the two compounds, ec50 and lc50 estimates varied from those for rana sphenocephala by no more than one order of magnitude when calculated on the basis of intended concentrations. removal of pesticides from water by the test animals was significant and it makes interpretation of results difficult. continuous-flow toxicity tests conflict with the ada ... | 1981 | 6975506 |
| taste responses to amino acids in the southern leopard frog, rana sphenocephala. | integrated taste recordings of the glossopharyngeal (ix) nerve innervating the tongue of the southern leopard frog were studied in response to various amino acids and quinine hydrochloride. amino acids and quinine hydrochloride elicited primarily phasic taste responses. acidic (l-aspartic and l-glutamic) and basic (l-lysine and l-arginine) amino acids, adjusted to ph8, were effective taste stimuli. all glossopharyngeal nerve twigs that responded to amino acid stimuli also responded to quinine; h ... | 1985 | 2863039 |
| vasculature of the parotoid glands of four species of toads (bufonidae: bufo). | the parotoid glands of toads (bufonidae) consist of large aggregations of granular glands located between the otic region of the skull and the scapular region. to determine the circulatory pattern of these glands, we perfused the vascular systems of bufo alvarius, b. marinus, b. terrestris, and b. valliceps with either india ink or microfil, a fine latex. the perfused glands were studied by gross dissection, microscopic examination, and histology. the vascular patterns of the parotoid glands wer ... | 2004 | 15108163 |
| effects of cover and predator size on survival and development of ranautricularia tadpoles. | size-limited predation is an important process during the development of many aquatic species, and mortality rates of early larval stages and small individuals can be particularly high. structurally complex habitats can mediate predator-prey interactions and provide a potentially important mechanism for decreasing predation pressure on larvae. to determine whether structurally complex habitats mediate predation on tadpoles of the southern leopard frog (ranautricularia), we designed a factorial e ... | 1998 | 28307940 |
| prostaglandin regulation of h+ secretion in amphibian epithelia. | the role of prostaglandins in regulating h+ excretion in amphibian epithelia was investigated. the abdominal skin of the southern leopard frog rana pipiens and the urinary bladder of the toad bufo marinus were used to measure proton excretion across their mucosal surface. prostaglandin f2 alpha (pgf2 alpha) produced a dose-dependent inhibition of h+ excretion across the frog skin. frogs pretreated with ibuprofen (30 mg.kg-1.day-1 for 3 days) showed an enhanced proton excretion similar to that ob ... | 1991 | 1903604 |
| molecular confirmation of frogs (anura) as hosts of corethrellidae (diptera) in the southeastern united states. | flies in the family corethrellidae edwards 1932 (diptera) are known to be attracted to the mating calls of male frogs. for the first time, the hosts of corethrellids were identified to species by analyzing bloodmeals taken from resting female flies. a portion of the cytochrome b gene was amplified and sequenced from blood-engorged flies using vertebrate-specific primers. the flies were collected over 6 yr at two locations in the southeastern united states from resting boxes and natural resting s ... | 2017 | 29117370 |
| preparatory immunity: seasonality of mucosal skin defenses and batrachochytrium infections in southern leopard frogs. | accurately predicting the impacts of climate change on wildlife health requires a deeper understanding of seasonal rhythms in host-pathogen interactions. the amphibian pathogen, batrachochytrium dendrobatidis (bd), exhibits seasonality in incidence; however, the role that biological rhythms in host defenses play in defining this pattern remains largely unknown. the aim of this study was to examine whether host immune and microbiome defenses against bd correspond with infection risk and seasonal ... | 2020 | 33179786 |
| agrochemical mixtures and amphibians: the combined effects of pesticides and fertilizer on stress, acetylcholinesterase activity, and bioaccumulation in a terrestrial environment. | tank mixtures are popular within the agricultural community because they are time- and cost-effective, but field applications leave nontarget organisms at risk of exposure. we explored the effects of a common herbicide (atrazine and alachlor) and fertilizer (urea) tank mixture on juvenile frog corticosterone stress levels, acetylcholinesterase (ache) activity, and pesticide bioaccumulation. single agrochemical or tank mixtures were applied to terrestrial microcosms, and then individual southern ... | 2019 | 30698848 |
| effect of hydration status on pesticide uptake in anurans following exposure to contaminated soils. | in this study, the impact of hydration status on dermal uptake of pesticides in two species of amphibians is examined. absorption of pesticides in anurans occurs primarily through a highly vascularized dermal seat patch; however, pesticides can also enter through the superficial dermis following exposure. despite the growing body of literature on dermal exposure in amphibians, little is known on how hydration status influences uptake. thus, the objective of this study was to investigate the infl ... | 2018 | 29594883 |
| move it or lose it: interspecific variation in risk response of pond-breeding anurans. | changes in behavior are often the proximate response of animals to human disturbance, with variability in tolerance levels leading some species to exhibit striking shifts in life history, fitness, and/or survival. thus, elucidating the effects of disturbance on animal behavior, and how this varies among taxonomically similar species with inherently different behaviors and life histories is of value for management and conservation. we evaluated the risk response of three anuran species-southern l ... | 2019 | 31211010 |
| effects of elevated corticosterone on humoral innate and antibody-mediated immunity in southern leopard frog (lithobates sphenocephalus) tadpoles. | as a free-living larval stage of a vertebrate, tadpoles are good subjects for the study of the development of physiological systems and the study of evolutionarily conserved, context-dependent responses to variable environments. while the basic components of innate and adaptive immune defenses in tadpoles are known, the impact of glucocorticoids on immune defenses in tadpoles is not well-studied. we completed four experiments to assess effects of elevation of corticosterone on humoral innate def ... | 2020 | 32798287 |
| a bacillus thuringiensis kurstaki biopesticide does not reduce hatching success or tadpole survival at environmentally relevant concentrations in southern leopard frogs (lithobates sphenocephalus). | amphibians are in global decline, and anthropogenic activities are known leading causes of their demise. thus the interaction between agriculture and amphibian health has been examined for decades. many facets of amphibian physiology and ecology place them at high risk among the nontarget organisms affected by agricultural byproducts. research has shown that many chemicals and fertilizers affect amphibian growth, reproduction, and survival. the impacts differ based on the type of agricultural by ... | 2020 | 31499575 |
| effects of the neonicotinoid insecticide clothianidin on southern leopard frog (rana sphenocephala) tadpole behavior. | neonicotinoid insecticides are highly water soluble with relatively long half-lives, which allows them to move into and persist in aquatic ecosystems. however, little is known of the impacts of neonicotinoids on non-target vertebrates, especially at sublethal concentrations. we evaluated the effects of the neonicotinoid clothianidin on the behavior of southern leopard frog tadpoles (rana sphenocephala) after a 96-h exposure at 6 concentrations, including 0 (control), 0.375, 0.75, 1.5, 3.0, 6.0 µ ... | 2019 | 31492972 |
| out in the cold and sick: low temperatures and fungal infections impair a frog's skin defenses. | amphibians worldwide continue to battle an emerging infectious disease, chytridiomycosis, caused by batrachochytrium dendrobatidis (bd). southern leopard frogs, rana sphenocephala, are known to become infected with this pathogen, yet they are considered 'of least concern' for declines due to chytridiomycosis. previous studies have shown that r. sphenocephala secretes four antimicrobial peptides (amps) onto their skin which may play an important role in limiting susceptibility to chytridiomycosis ... | 2019 | 31488625 |
| seasonality in batrachochytrium dendrobatidis detection in amphibians in central oklahoma, usa. | chytridiomycosis, an infectious disease caused by the fungus batrachochytrium dendrobatidis (chytrid or bd), has not been well studied in oklahoma. this is of particular concern regarding the connection between seasonality and chytrid infection. to further investigate this connection, chytrid prevalence and infection load were quantified within amphibians in central oklahoma from march to october, across two sites in oklahoma co. and two sites in cleveland co. the results show a trend between se ... | 2019 | 31260222 |
| effect of individual and combined treatments of pesticide, fertilizer, and salt on growth and corticosterone levels of larval southern leopard frogs (lithobates sphenocephala). | human activities have introduced a variety of chemicals, including pesticides, fertilizers, and salt, into the environment, which may have deleterious effects on the organisms inhabiting these areas. amphibians are especially susceptible to absorption of chemical pollutants. to determine the possible combined effects of these chemicals on amphibian development and stress levels, southern leopard frog (lithobates sphenocephala) larvae were exposed to one of eight individual or combined treatments ... | 2019 | 31020372 |
| comparative analysis of amphibian somite morphogenesis: cell rearrangement patterns during rosette formation and myoblast fusion. | detailed sem observations of the changes in cellular morphology, arrangements, and contacts that occur during the process of somite formation were made in two species of urodele amphibians, ambystoma mexicanum and pleurodeles waltlii, and one species of anuran amphibian, rana sphenocephala. after fixation, embryos were fractured transversely, horizontally, and parasagittally, and the intrasomitic cellular arrangement pattern was examined with the sem. it was found that ambystoma and pleurodeles ... | 1981 | 7338706 |
| the importance of species: pygmy rattlesnake venom toxicity differs between native prey and related non-native species. | venom toxicity assessments are often based upon non-native surrogate prey species that are not consumed in the wild by the venomous predator. this raises questions about the relevance of toxicity results on these "model" prey in addressing ecological or evolutionary questions about venom effects on native prey. we explore this issue by comparing the toxicity of venom from pygmy rattlesnakes (sistrurus miliarius) on taxonomically-diverse sets of model (non-native) and native prey. specifically, w ... | 2018 | 29410327 |
| pathogen dynamics in an invasive frog compared to native species. | emerging infectious diseases threaten the survival of wildlife populations and species around the world. in particular, amphibians are experiencing population declines and species extinctions primarily in response to two pathogens, the fungus batrachochytrium dendrobatidis (bd) and the iridovirus ranavirus (rv). here, we use field surveys and quantitative (q)pcr to compare infection intensity and prevalence of bd and rv across species and seasons on jekyll island, a barrier island off the coast ... | 2019 | 31332577 |
| distinguishing anuran species by high-resolution melting analysis of the coi barcode (coi-hrm). | taxonomic identification can be difficult when two or more species appear morphologically similar. dna barcoding based on the sequence of the mitochondrial cytochrome c oxidase 1 gene (coi) is now widely used in identifying animal species. high-resolution melting analysis (hrm) provides an alternative method for detecting sequence variations among amplicons without having to perform dna sequencing. the purpose of this study was to determine whether hrm of the coi barcode can be used to distingui ... | 2019 | 31871662 |