The Experts below are selected from a list of 1548 Experts worldwide ranked by ideXlab platform
Andrew R Blaustein - One of the best experts on this subject based on the ideXlab platform.
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Reproductive characteristics of American bullfrogs (Lithobates catesbeianus) in their invasive range of the Pacific Northwest, USA
Scientific Reports, 2020Co-Authors: Jenny Urbina, Andrew R Blaustein, Evan M Bredeweg, Christopher Cousins, Tiffany S GarciaAbstract:Invasive species pose a major threat to global biodiversity. The effects of invasive species can be strongly influenced and potentially mediated by their reproductive characteristics, such as fecundity, egg production, and duration and number of reproductive events. Selection for smaller body size at first reproduction can also play a role in their establishment, facilitating colonization and spread. The American bullfrog, native to the eastern U.S. ( Lithobates catesbeianus ), is a species that has invaded more than 40 countries across 4 continents. This species has become especially prevalent in the western United States since its introduction in the early 1900s. This study characterized reproductive characteristics of bullfrogs with emphasis on the minimum size at which males and females reach sexual maturity in the Willamette Valley, Oregon, USA invasion range. We collected and dissected 121 individuals in 2013 and 2017, quantifying characteristics of sexual maturity including snout-vent length, total length, sex, tympanum diameter, presence of distended oviducts or eggs for females, and testes length and sperm activity in males. Our results showed that the minimum reproductive size of both males and females was smaller relative to bullfrogs in their native range as well as in populations across their invasive range. Reduction in size at reproductive maturity is likely impacting the invasive success of American bullfrogs and this study gives us insight on management actions to control the invasion. Applying this insight, managers can adjust their definition of reproductively active adults, increasing the target population of culling and other control methods.
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Experimental evidence for american bullfrog (Lithobates catesbeianus) susceptibility to chytrid fungus (Batrachochytrium dendrobatidis). EcoHealth 10:166–71
2020Co-Authors: Stephanie S Gervasi, Tara Chestnut, Jenny Urbina, Rick A Relyea, Jessica Hua, Andrew R BlausteinAbstract:Abstract: The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been associated with global amphibian population declines and extinctions. American bullfrogs (Lithobates catesbeianus) are widely reported to be a tolerant host and a carrier of Bd that spreads the pathogen to less tolerant hosts. Here, we examined whether bullfrogs raised from eggs to metamorphosis in outdoor mesocosms were susceptible to Bd. We experimentally exposed metamorphic juveniles to Bd in the laboratory and compared mortality rates of pathogen-exposed animals to controls (non-exposed) in two separate experiments; one using a Bd strain isolated from a Western toad and another using a strain isolated from an American bullfrog. We wanted to examine whether metamorphic bullfrogs were susceptible to either of these strains. We show that bullfrogs were susceptible to one strain of Bd and not the other. In both experiments, infection load detected in the skin decreased over time, suggesting that metamorphic bullfrogs from some populations may be inefficient longterm carriers of Bd
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host pathogen dynamics among the invasive american bullfrog Lithobates catesbeianus and chytrid fungus batrachochytrium dendrobatidis
Hydrobiologia, 2018Co-Authors: Jenny Urbina, Evan M Bredeweg, Tiffany S Garcia, Andrew R BlausteinAbstract:The combination of introduced host species and emerging pathogens can result in unanticipated disease dynamics and novel host–pathogen interactions. The American bullfrog (Lithobates catesbeianus) is a successful invasive amphibian in the western U.S. that can act as a host to the emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd) implicated in the decline of amphibian populations worldwide. We examined if wild-caught invasive bullfrogs were differentially susceptible to two regionally distinct isolates of Bd. Newly metamorphosed bullfrog individuals were exposed to either a Bd strain originally isolated from bullfrogs in their endemic range or a strain from the invaded range in the western U.S. We quantified initial infection load and compared mortality rates and changes in infection load after 30 days to determine strain-specific susceptibility. Wild-caught bullfrogs from the western U.S. were particularly susceptible to an eastern Bd strain. Although infection loads were not different between strains, individuals exposed to the western strain survived, suggesting the ability to reduce their infection. Our findings highlight differences between strains and response variation of an invasive species host.
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experimental evidence for american bullfrog Lithobates catesbeianus susceptibility to chytrid fungus batrachochytrium dendrobatidis
Ecohealth, 2013Co-Authors: Stephanie S Gervasi, Tara Chestnut, Jenny Urbina, Rick A Relyea, Andrew R BlausteinAbstract:The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been associated with global amphibian population declines and extinctions. American bullfrogs (Lithobates catesbeianus) are widely reported to be a tolerant host and a carrier of Bd that spreads the pathogen to less tolerant hosts. Here, we examined whether bullfrogs raised from eggs to metamorphosis in outdoor mesocosms were susceptible to Bd. We experimentally exposed metamorphic juveniles to Bd in the laboratory and compared mortality rates of pathogen-exposed animals to controls (non-exposed) in two separate experiments; one using a Bd strain isolated from a Western toad and another using a strain isolated from an American bullfrog. We wanted to examine whether metamorphic bullfrogs were susceptible to either of these strains. We show that bullfrogs were susceptible to one strain of Bd and not the other. In both experiments, infection load detected in the skin decreased over time, suggesting that metamorphic bullfrogs from some populations may be inefficient long-term carriers of Bd.
Dario Elbio Cardozo - One of the best experts on this subject based on the ideXlab platform.
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american bullfrog Lithobates catesbeianus shaw 1802 invasion in argentina
Biological Invasions, 2010Co-Authors: Mauricio Sebastián Akmentins, Dario Elbio CardozoAbstract:The American bullfrog (Lithobates catesbeianus) has been introduced throughout the world over the past two centuries. This taxa is a potentially devastating invader because of its large size, prolific reproductive output, and broad ecological niche. Consequently, the extent of this ongoing biological invasion is an increasing conservation concern. In Argentina, several introduced populations have been reported. In most cases, these introductions have been intentional or incidental releases from breeding facilities, yet the consequences and effective controls for captive-breeding programs have not been assessed by government environmental agencies. Further studies are needed regarding the trophic ecology, reproductive biology, ecological niche, and chytrid fungus infection prevalence to predict the ultimate impacts of this species on native ecosystems. The aim of this work is to report a new alien population of L. catesbeianus at La Candelaria, Salta province, Argentina. This record represents the first population of American bullfrogs detected in northwestern Argentina.
Jenny Urbina - One of the best experts on this subject based on the ideXlab platform.
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Reproductive characteristics of American bullfrogs (Lithobates catesbeianus) in their invasive range of the Pacific Northwest, USA
Scientific Reports, 2020Co-Authors: Jenny Urbina, Andrew R Blaustein, Evan M Bredeweg, Christopher Cousins, Tiffany S GarciaAbstract:Invasive species pose a major threat to global biodiversity. The effects of invasive species can be strongly influenced and potentially mediated by their reproductive characteristics, such as fecundity, egg production, and duration and number of reproductive events. Selection for smaller body size at first reproduction can also play a role in their establishment, facilitating colonization and spread. The American bullfrog, native to the eastern U.S. ( Lithobates catesbeianus ), is a species that has invaded more than 40 countries across 4 continents. This species has become especially prevalent in the western United States since its introduction in the early 1900s. This study characterized reproductive characteristics of bullfrogs with emphasis on the minimum size at which males and females reach sexual maturity in the Willamette Valley, Oregon, USA invasion range. We collected and dissected 121 individuals in 2013 and 2017, quantifying characteristics of sexual maturity including snout-vent length, total length, sex, tympanum diameter, presence of distended oviducts or eggs for females, and testes length and sperm activity in males. Our results showed that the minimum reproductive size of both males and females was smaller relative to bullfrogs in their native range as well as in populations across their invasive range. Reduction in size at reproductive maturity is likely impacting the invasive success of American bullfrogs and this study gives us insight on management actions to control the invasion. Applying this insight, managers can adjust their definition of reproductively active adults, increasing the target population of culling and other control methods.
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Experimental evidence for american bullfrog (Lithobates catesbeianus) susceptibility to chytrid fungus (Batrachochytrium dendrobatidis). EcoHealth 10:166–71
2020Co-Authors: Stephanie S Gervasi, Tara Chestnut, Jenny Urbina, Rick A Relyea, Jessica Hua, Andrew R BlausteinAbstract:Abstract: The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been associated with global amphibian population declines and extinctions. American bullfrogs (Lithobates catesbeianus) are widely reported to be a tolerant host and a carrier of Bd that spreads the pathogen to less tolerant hosts. Here, we examined whether bullfrogs raised from eggs to metamorphosis in outdoor mesocosms were susceptible to Bd. We experimentally exposed metamorphic juveniles to Bd in the laboratory and compared mortality rates of pathogen-exposed animals to controls (non-exposed) in two separate experiments; one using a Bd strain isolated from a Western toad and another using a strain isolated from an American bullfrog. We wanted to examine whether metamorphic bullfrogs were susceptible to either of these strains. We show that bullfrogs were susceptible to one strain of Bd and not the other. In both experiments, infection load detected in the skin decreased over time, suggesting that metamorphic bullfrogs from some populations may be inefficient longterm carriers of Bd
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host pathogen dynamics among the invasive american bullfrog Lithobates catesbeianus and chytrid fungus batrachochytrium dendrobatidis
Hydrobiologia, 2018Co-Authors: Jenny Urbina, Evan M Bredeweg, Tiffany S Garcia, Andrew R BlausteinAbstract:The combination of introduced host species and emerging pathogens can result in unanticipated disease dynamics and novel host–pathogen interactions. The American bullfrog (Lithobates catesbeianus) is a successful invasive amphibian in the western U.S. that can act as a host to the emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd) implicated in the decline of amphibian populations worldwide. We examined if wild-caught invasive bullfrogs were differentially susceptible to two regionally distinct isolates of Bd. Newly metamorphosed bullfrog individuals were exposed to either a Bd strain originally isolated from bullfrogs in their endemic range or a strain from the invaded range in the western U.S. We quantified initial infection load and compared mortality rates and changes in infection load after 30 days to determine strain-specific susceptibility. Wild-caught bullfrogs from the western U.S. were particularly susceptible to an eastern Bd strain. Although infection loads were not different between strains, individuals exposed to the western strain survived, suggesting the ability to reduce their infection. Our findings highlight differences between strains and response variation of an invasive species host.
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experimental evidence for american bullfrog Lithobates catesbeianus susceptibility to chytrid fungus batrachochytrium dendrobatidis
Ecohealth, 2013Co-Authors: Stephanie S Gervasi, Tara Chestnut, Jenny Urbina, Rick A Relyea, Andrew R BlausteinAbstract:The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been associated with global amphibian population declines and extinctions. American bullfrogs (Lithobates catesbeianus) are widely reported to be a tolerant host and a carrier of Bd that spreads the pathogen to less tolerant hosts. Here, we examined whether bullfrogs raised from eggs to metamorphosis in outdoor mesocosms were susceptible to Bd. We experimentally exposed metamorphic juveniles to Bd in the laboratory and compared mortality rates of pathogen-exposed animals to controls (non-exposed) in two separate experiments; one using a Bd strain isolated from a Western toad and another using a strain isolated from an American bullfrog. We wanted to examine whether metamorphic bullfrogs were susceptible to either of these strains. We show that bullfrogs were susceptible to one strain of Bd and not the other. In both experiments, infection load detected in the skin decreased over time, suggesting that metamorphic bullfrogs from some populations may be inefficient long-term carriers of Bd.
Monica Jonescosta - One of the best experts on this subject based on the ideXlab platform.
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effects of lithium and selenium in the tail muscle of american bullfrog tadpoles Lithobates catesbeianus during premetamorphosis
Environmental Science and Pollution Research, 2021Co-Authors: Felipe Augusto Pintovidal, Cleoni Dos Santos Carvalho, Fabio Camargo Abdalla, Heidi Samantha Moraes Utsunomiya, Raquel Fernanda Salla, Monica JonescostaAbstract:The amphibian populations have faced a drastic decline over the past decades. This decline has been associated with the presence of contaminants in the environment, among other environmental stressors. The present study tested the responses following the exposure to lithium (2.5 mg L−1) and selenium (10μg L−1), both isolated and as a mixture, on the metabolic status of the tail muscle of premetamorphic American bullfrog (Lithobates catesbeianus) through the assessment of the total protein content, mobilization of glucose and triglycerides, and the activity of lactate dehydrogenase (LDH). The exposure followed a 21-day assay with two sampling periods (on the 7th and 21st day after the onset of exposure) to evaluate the effects over time. The group exposed to the mixture presented a statistically decreased LDH activity (P 0.05). The total protein content did not show any statistical difference in the treated groups throughout the experiment (P > 0.05). The presented results highlight the importance of the assessment of mixtures that can occur in the environment, since the combination of contaminants may elicit distinct toxicity compared with the effects triggered by the chemicals isolated.
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metabolic immunologic and histopathologic responses on premetamorphic american bullfrog Lithobates catesbeianus following exposure to lithium and selenium
Environmental Pollution, 2021Co-Authors: Felipe Augusto Pintovidal, Cleoni Dos Santos Carvalho, Fabio Camargo Abdalla, Heidi Samantha Moraes Utsunomiya, Raquel Fernanda Salla, Leticia Ceschibertoli, Renan Henrique Da Silva, Monica JonescostaAbstract:Abstract The presence of chemicals and the destruction of freshwater habitats have been addressed as one of the reasons for the decline in the amphibians’ populations worldwide. Considering the threat that these animals have been suffering in tropical regions, the present study tested if the Brazilian legislation, concerning the permissive levels of lithium and selenium in water bodies and effluents, warrants the protection of aquatic life. To do so, we assessed the metabolic, immunologic, and histopathologic alterations in liver samples of American bullfrog (Lithobates catesbeianus), at the premetamorphic stage, through biomarkers indicative of general energetic status, i.e., glucose, lipid, and protein metabolism using biochemical and histochemical approaches. The immunologic responses were assessed by the quantification of melanomacrophage centres (MMCs); the histopathologic evaluation of the liver sections was also performed. The assay was carried out over 21 days with two periods of sampling (after 7 and 21 days) to assess the effects of exposure over time. The animals were exposed to the considered safe levels of lithium (2.5 mg L−1) and selenium (10 μg L−1), both, isolated and mixed. The exposed animals showed alterations in glucose and lipid metabolism throughout the experiment. The intense presence of MMCs and histopathological responses are compatible with hepatotoxicity. The toxicity expressed by the employed animal model indicates that the Brazilian environmental legislation for the protection of aquatic life needs to be updated. With this study, we intend to provide data for better environmental policies and bring attention to sublethal effects triggered by the presence of contaminants in the aquatic environment.
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metamorphic acceleration following the exposure to lithium and selenium on american bullfrog tadpoles Lithobates catesbeianus
Ecotoxicology and Environmental Safety, 2021Co-Authors: Felipe Augusto Pinto Vidal, Cleoni Dos Santos Carvalho, Fabio Camargo Abdalla, Heidi Samantha Moraes Utsunomiya, Raquel Fernanda Salla, Leonardo Antonio Teixeira Oliveira, Monica JonescostaAbstract:Abstract To regulate the presence of contaminants in Brazilian water, the Brazilian Environmental Council (CONAMA) promulgates regulations regarding the concentrations of given compounds that are supposed to be safe for aquatic life. Considering these regulations, this study tested the effects of considered safe levels of lithium (2.5 mgL−1) and selenium (0.01 mgL−1), isolated and mixed, on the American bullfrog (Lithobates catesbeianus) tadpoles. The evaluation was done through the use of biomarkers of larval development as total wet weight (TWW), snout-vent-length (SVL), hind-limb-length (HLL), activity level (AL), histologic evaluation of the thyroid gland and the mortality rate. The tadpoles were allocated into four groups (n = 20 each): a control group (CT); a group exposed to lithium (LI), a group exposed to selenium (SE), and a group exposed to both lithium and selenium (SELI). The whole assay was carried out over 21 days, with two rounds of data collection (on 7th and 21st day) to evaluate the responses over time. A statistical reduction in the AL was observed in the tadpoles from the LI and SELI groups after 7 days of exposure, the same pattern was observed after 21 days. Histological analyses of the thyroid gland showed signs of up-regulation (i.e. statistic reduction in number and area of the follicles, as well a significant reduction in the area of the gland) in all exposed groups, which represents an endocrine response as an adaptative strategy to deal with polluted aquatic environment. The stress triggered by the polluted medium is discussed.
Tiffany S Garcia - One of the best experts on this subject based on the ideXlab platform.
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Reproductive characteristics of American bullfrogs (Lithobates catesbeianus) in their invasive range of the Pacific Northwest, USA
Scientific Reports, 2020Co-Authors: Jenny Urbina, Andrew R Blaustein, Evan M Bredeweg, Christopher Cousins, Tiffany S GarciaAbstract:Invasive species pose a major threat to global biodiversity. The effects of invasive species can be strongly influenced and potentially mediated by their reproductive characteristics, such as fecundity, egg production, and duration and number of reproductive events. Selection for smaller body size at first reproduction can also play a role in their establishment, facilitating colonization and spread. The American bullfrog, native to the eastern U.S. ( Lithobates catesbeianus ), is a species that has invaded more than 40 countries across 4 continents. This species has become especially prevalent in the western United States since its introduction in the early 1900s. This study characterized reproductive characteristics of bullfrogs with emphasis on the minimum size at which males and females reach sexual maturity in the Willamette Valley, Oregon, USA invasion range. We collected and dissected 121 individuals in 2013 and 2017, quantifying characteristics of sexual maturity including snout-vent length, total length, sex, tympanum diameter, presence of distended oviducts or eggs for females, and testes length and sperm activity in males. Our results showed that the minimum reproductive size of both males and females was smaller relative to bullfrogs in their native range as well as in populations across their invasive range. Reduction in size at reproductive maturity is likely impacting the invasive success of American bullfrogs and this study gives us insight on management actions to control the invasion. Applying this insight, managers can adjust their definition of reproductively active adults, increasing the target population of culling and other control methods.
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host pathogen dynamics among the invasive american bullfrog Lithobates catesbeianus and chytrid fungus batrachochytrium dendrobatidis
Hydrobiologia, 2018Co-Authors: Jenny Urbina, Evan M Bredeweg, Tiffany S Garcia, Andrew R BlausteinAbstract:The combination of introduced host species and emerging pathogens can result in unanticipated disease dynamics and novel host–pathogen interactions. The American bullfrog (Lithobates catesbeianus) is a successful invasive amphibian in the western U.S. that can act as a host to the emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd) implicated in the decline of amphibian populations worldwide. We examined if wild-caught invasive bullfrogs were differentially susceptible to two regionally distinct isolates of Bd. Newly metamorphosed bullfrog individuals were exposed to either a Bd strain originally isolated from bullfrogs in their endemic range or a strain from the invaded range in the western U.S. We quantified initial infection load and compared mortality rates and changes in infection load after 30 days to determine strain-specific susceptibility. Wild-caught bullfrogs from the western U.S. were particularly susceptible to an eastern Bd strain. Although infection loads were not different between strains, individuals exposed to the western strain survived, suggesting the ability to reduce their infection. Our findings highlight differences between strains and response variation of an invasive species host.
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antipredator behavior of american bullfrogs Lithobates catesbeianus in a novel environment
Ethology, 2012Co-Authors: Tiffany S Garcia, Lindsey L Thurman, Jennifer C Rowe, Stephen M SelegoAbstract:Invasive species capable of recognizing potential predators may have increased establishment rates in novel environments. Individuals may retain historical predator recognition and invoke innate responses in the presence of taxonomically or ecologically similar predators, generalize antipredator responses, or learn to avoid risky species in novel environments. Invasive amphibians in aquatic environments often use chemical cues to assess predation risk and learn to avoid novel predators via direct experience and/or associated chemical cues. Ontogeny may also influence recognition; experience with predators may need to occur at certain developmental stages for individuals to respond correctly. We tested predator recognition in invasive American bullfrog (Lithobates catesbeianus) tadpoles that varied in experience with fish predators at the population and individual scale. We found that bullfrog tadpoles responded to a historical predator, largemouth bass (Micropterus salmoides), only if the population was locally sympatric with largemouth bass. Individuals from a population that did not co-occur with largemouth bass did not increase refuge use in response to either largemouth bass chemical cues alone or chemical cues with diet cues (largemouth bass fed bullfrog tadpoles). To test whether this behavioral response was generalized across fish predators, we exposed tadpoles to rainbow trout (Oncorhynchus mykiss) and found that tadpoles could not recognize this novel predator regardless of co-occurrence with other fish species. These results suggest that environment may be more important for predator recognition than evolutionary history for this invasive species, and individuals do not retain predator recognition or generalize across fish predators.
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population genetics of introduced bullfrogs rana Lithobates catesbeianus in the willamette valley oregon usa
Biological Invasions, 2011Co-Authors: Chris W Funk, Tiffany S Garcia, George A Cortina, Rebbecca H HillAbstract:The American bullfrog, Rana (Lithobates) catesbeianus, is endemic to eastern North America, but has been introduced to approximately 40 countries on four continents and is considered one of the hundred worst invasive alien species in the world. Here, we investigated the genetics of invasive bullfrogs in the Willamette Valley, Oregon, USA, where bullfrogs are widespread and abundant to determine: (1) the minimum number of bullfrog introductions; (2) the native source population(s); and (3) whether genetic variation is reduced compared to source populations. To answer these questions, we analyzed partial sequences of the mitochondrial cytochrome b gene for 251 bullfrogs from the Willamette Valley and the native range. We found that bullfrogs from the Mississippi River basin and Great Lakes region were introduced at least once to the Willamette Valley. Genetic variation measured as haplotype diversity (h) and nucleotide diversity (πn) was not significantly different between Willamette Valley and source populations. Our results were in contrast to a recent genetic analysis of invasive bullfrog populations in Europe, which found that genetic variation in European bullfrog populations was much lower than in source populations. European bullfrogs also originated from different source populations than Willamette Valley bullfrogs. The difference in genetic composition between Willamette Valley and European bullfrogs is likely due to differences in their invasion histories and may have implications for the potential of bullfrogs in these different regions to adapt and expand.