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Ujszegi J, Ujhegyi N, Balogh E, Mikó Z, Kásler A, Hettyey A, Bókony V. No sex-dependent mortality in an amphibian upon infection with the chytrid fungus, Batrachochytrium dendrobatidis. Ecol Evol 2024; 14:e70219. [PMID: 39219568 PMCID: PMC11362217 DOI: 10.1002/ece3.70219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 08/07/2024] [Accepted: 08/09/2024] [Indexed: 09/04/2024] Open
Abstract
One of the major factors driving the currently ongoing biodiversity crisis is the anthropogenic spread of infectious diseases. Diseases can have conspicuous consequences, such as mass mortality events, but may also exert covert but similarly severe effects, such as sex ratio distortion via sex-biased mortality. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is among the most important threats to amphibian biodiversity. Yet, whether Bd infection can skew sex ratios in amphibians is currently unknown, although such a hidden effect may cause the already dwindling amphibian populations to collapse. To investigate this possibility, we collected common toad (Bufo bufo) tadpoles from a natural habitat in Hungary and continuously treated them until metamorphosis with sterile Bd culture medium (control), or a liquid culture of a Hungarian or a Spanish Bd isolate. Bd prevalence was high in animals that died during the experiment but was almost zero in individuals that survived until the end of the experiment. Both Bd treatments significantly reduced survival after metamorphosis, but we did not observe sex-dependent mortality in either treatment. However, a small number of genotypically female individuals developed male phenotype (testes) in the Spanish Bd isolate treatment. Therefore, future research is needed to ascertain if larval Bd infection can affect sex ratio in common toads through female-to-male sex reversal.
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Affiliation(s)
- János Ujszegi
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
- Department of Systematic Zoology and EcologyELTE Eötvös Loránd UniversityBudapestHungary
| | - Nikolett Ujhegyi
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
| | - Emese Balogh
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
- Department of ZoologyUniversity of Veterinary Medicine BudapestBudapestHungary
| | - Zsanett Mikó
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
| | - Andrea Kásler
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
- Department of Systematic Zoology and EcologyELTE Eötvös Loránd UniversityBudapestHungary
- Doctoral School of Biology, Institute of BiologyELTE Eötvös Loránd UniversityBudapestHungary
| | - Attila Hettyey
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
- Department of Systematic Zoology and EcologyELTE Eötvös Loránd UniversityBudapestHungary
| | - Veronika Bókony
- Department of Evolutionary Ecology, HUN‐REN Centre for Agricultural ResearchPlant Protection InstituteBudapestHungary
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Orford JT, Tan H, Martin JM, Wong BBM, Alton LA. Impacts of Exposure to Ultraviolet Radiation and an Agricultural Pollutant on Morphology and Behavior of Tadpoles (Limnodynastes tasmaniensis). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:1615-1626. [PMID: 38837484 DOI: 10.1002/etc.5895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/27/2024] [Accepted: 04/17/2024] [Indexed: 06/07/2024]
Abstract
Amphibians are the most threatened vertebrate class globally. Multiple factors have been implicated in their global decline, and it has been hypothesized that interactions between stressors may be a major cause. Increased ultraviolet (UV) radiation, as a result of ozone depletion, has been identified as one such stressor. Exposure to UV radiation has been shown to have detrimental effects on amphibians and can exacerbate the effects of other stressors, such as chemical pollutants. Chemical pollution has likewise been recognized as a major factor contributing to amphibian declines, particularly, endocrine-disrupting chemicals. In this regard, 17β-trenbolone is a potent anabolic steroid used in the agricultural industry to increase muscle mass in cattle and has been repeatedly detected in the environment where amphibians live and breed. At high concentrations, 17β-trenbolone has been shown to impact amphibian survival and gonadal development. In the present study, we investigated the effects of environmentally realistic UV radiation and 17β-trenbolone exposure, both in isolation and in combination, on the morphology and behavior of tadpoles (Limnodynastes tasmaniensis). We found that neither stressor in isolation affected tadpoles, nor did we find any interactive effects. The results from our 17β-trenbolone treatment are consistent with recent research suggesting that, at environmentally realistic concentrations, tadpoles may be less vulnerable to this pollutant compared to other vertebrate classes. The absence of UV radiation-induced effects found in the present study could be due to species-specific variation in susceptibility, as well as the dosage utilized. We suggest that future research should incorporate long-term studies with multiple stressors to accurately identify the threats to, and subsequent consequences for, amphibians under natural conditions. Environ Toxicol Chem 2024;43:1615-1626. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Jack T Orford
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Hung Tan
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Jake M Martin
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Bob B M Wong
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Lesley A Alton
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
- Centre for Geometric Biology, Monash University, Melbourne, Victoria, Australia
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Rowley JJL, Symons A, Doyle C, Hall J, Rose K, Stapp L, Lettoof DC. Broad-scale pesticide screening finds anticoagulant rodenticide and legacy pesticides in Australian frogs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172526. [PMID: 38636866 DOI: 10.1016/j.scitotenv.2024.172526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/20/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Pesticide contamination poses a significant threat to non-target wildlife, including amphibians, many of which are already highly threatened. This study assessed the extent of pesticide exposure in dead frogs collected during a mass mortality event across eastern New South Wales, Australia between July 2021 and March 2022. Liver tissue from 77 individual frogs of six species were analysed for >600 legacy and contemporary pesticides, including rodenticides. More than a third (36 %) of the liver samples contained at least one of the following pesticides: brodifacoum, dieldrin, DDE, heptachlor/heptachlor epoxide, fipronil sulfone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA). Brodifacoum, a second-generation anticoagulant rodenticide, was found in four of the six frog species analysed: the eastern banjo frog (Limnodynastes dumerilii), cane toad (Rhinella marina), green tree frog (Litoria caerulea) and Peron's tree frog (Litoria peronii). This is the first report of anticoagulant rodenticide detected in wild amphibians, raising concerns about potential impacts on frogs and extending the list of taxa shown to accumulate rodenticides. Dieldrin, a banned legacy pesticide, was also detected in two species: striped marsh frog (Limnodynastes peronii) and green tree frog (Litoria caerulea). The toxicological effects of these pesticides on frogs are difficult to infer due to limited comparable studies; however, due to the low frequency of detection the presence of these pesticides was not considered a major contributing factor to the mass mortality event. Additional research is needed to investigate the effects of pesticide exposure on amphibians, particularly regarding the impacts of second-generation anticoagulant rodenticides. There is also need for continued monitoring and improved conservation management strategies for the mitigation of the potential threat of pesticide exposure and accumulation in amphibian populations.
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Affiliation(s)
- Jodi J L Rowley
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, New South Wales 2010, Australia; Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew Symons
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Christopher Doyle
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Jane Hall
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Laura Stapp
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Damian C Lettoof
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Centre for Environment and Life Sciences, Floreat, Western Australia 6014, Australia; School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, Western Australia 6102, Australia
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Chew A, West M, Berger L, Brannelly LA. The impacts of water quality on the amphibian chytrid fungal pathogen: A systematic review. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13274. [PMID: 38775382 PMCID: PMC11110485 DOI: 10.1111/1758-2229.13274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 04/06/2024] [Indexed: 05/25/2024]
Abstract
The pathogenic fungus Batrachochytrium dendrobatidis has caused declines of amphibians worldwide. Yet our understanding of how water quality influences fungal pathogenicity is limited. Here, we reviewed experimental studies on the effect of water quality on this pathogen to determine which parameters impacted disease dynamics consistently. The strongest evidence for protective effects is salinity which shows strong antifungal properties in hosts at natural levels. Although many fungicides had detrimental effects on the fungal pathogen in vitro, their impact on the host is variable and they can worsen infection outcomes. However, one fungicide, epoxiconazole, reduced disease effects experimentally and likely in the field. While heavy metals are frequently studied, there is weak evidence that they influence infection outcomes. Nitrogen and phosphorous do not appear to impact pathogen growth or infection in the amphibian host. The effects of other chemicals, like pesticides and disinfectants on infection were mostly unclear with mixed results or lacking an in vivo component. Our study shows that water chemistry does impact disease dynamics, but the effects of specific parameters require more investigation. Improving our understanding of how water chemistry influences disease dynamics will help predict the impact of chytridiomycosis, especially in amphibian populations affected by land use changes.
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Affiliation(s)
- Adeline Chew
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Matt West
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Lee Berger
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
| | - Laura A. Brannelly
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
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Aulsebrook LC, Wong BBM, Hall MD. Pharmaceutical pollution alters the cost of bacterial infection and its relationship to pathogen load. Proc Biol Sci 2024; 291:20231273. [PMID: 38196353 PMCID: PMC10777164 DOI: 10.1098/rspb.2023.1273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 12/01/2023] [Indexed: 01/11/2024] Open
Abstract
The relationship between pathogen proliferation and the cost of infection experienced by a host drives the ecology and evolution of host-pathogen dynamics. While environmental factors can shape this relationship, there is currently limited knowledge on the consequences of emerging contaminants, such as pharmaceutical pollutants, on the relationship between a pathogen's growth within the host and the damage it causes, termed its virulence. Here, we investigated how exposure to fluoxetine (Prozac), a commonly detected psychoactive pollutant, could alter this key relationship using the water flea Daphnia magna and its bacterial pathogen Pasteuria ramosa as a model system. Across a variety of fluoxetine concentrations, we found that fluoxetine shaped the damage a pathogen caused, such as the reduction in fecundity or intrinsic growth experienced by infected individuals, but with minimal change in average pathogen spore loads. Instead, fluoxetine modified the relationship between the degree of pathogen proliferation and its virulence, with both the strength of this trade-off and the component of host fitness most affected varying by fluoxetine concentration and host genotype. Our study underscores the potential for pharmaceutical pollution to modify the virulence of an invading pathogen, as well as the fundamental trade-off between host and pathogen fitness, even at the trace amounts increasingly found in natural waterways.
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Affiliation(s)
- Lucinda C. Aulsebrook
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Bob B. M. Wong
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Matthew D. Hall
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
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Hawley L, Smalling KL, Glaberman S. Critical review of the phytohemagglutinin assay for assessing amphibian immunity. CONSERVATION PHYSIOLOGY 2023; 11:coad090. [PMID: 38090122 PMCID: PMC10714196 DOI: 10.1093/conphys/coad090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/15/2023] [Accepted: 10/26/2023] [Indexed: 04/26/2024]
Abstract
Infectious diseases are a major driver of the global amphibian decline. In addition, many factors, including genetics, stress, pollution, and climate change can influence the response to pathogens. Therefore, it is important to be able to evaluate amphibian immunity in the laboratory and in the field. The phytohemagglutinin (PHA) assay is an inexpensive and relatively non-invasive tool that has been used extensively to assess immunocompetence, especially in birds, and more recently in amphibians. However, there is substantial variation in experimental methodology among amphibian PHA studies in terms of species and life stages, PHA doses and injection sites, and use of experimental controls. Here, we compile and compare all known PHA studies in amphibians to identify knowledge gaps and develop best practices for future work. We found that research has only been conducted on a limited number of species, which may not reflect the diversity of amphibians. There is also a lack of validation studies in most species, so that doses and timing of PHA injection and subsequent swelling measurements may not effectively evaluate immunocompetence. Based on these and other findings, we put forward a set of recommendations to make future PHA studies more consistent and improve the ability to utilize this assay in wild populations, where immune surveillance is greatly needed.
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Affiliation(s)
- Lauren Hawley
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
| | - Kelly L Smalling
- New Jersey Water Science Center, U.S. Geological Survey, Lawrenceville, NJ, USA
| | - Scott Glaberman
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
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Barragan EM, Hoskins TD, Allmon EB, McQuigg JL, Hamilton MT, Christian EN, Coogan GSM, Searle CL, Choi YJ, Lee LS, Hoverman JT, Sepúlveda MS. Toxicities of Legacy and Current-Use PFAS in an Anuran: Do Larval Exposures Influence Responses to a Terrestrial Pathogen Challenge? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19180-19189. [PMID: 37962853 DOI: 10.1021/acs.est.3c03191] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Legacy polyfluoroalkyl substances (PFAS) [perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA)] are being replaced by various other fluorinated compounds, such as hexafluoropropylene oxide dimer acid (GenX). These alternatives are thought to be less bioaccumulative and, therefore, less toxic than legacy PFAS. Contaminant exposures occur concurrently with exposure to natural stressors, including the fungal pathogen Batrachocytrium dendrobatidis (Bd). Despite evidence that other pollutants can increase the adverse effects of Bd on anurans, no studies have examined the interactive effects of Bd and PFAS. This study tested the growth and developmental effects of PFOS, PFOA, and GenX on gray treefrog (Hyla versicolor) tadpoles, followed by a Bd challenge after metamorphosis. Despite PFAS exposure only occurring during the larval stage, carry-over effects on growth were observed post metamorphosis. Further, PFAS interacted with Bd exposure to influence growth; Bd-exposed animals had significantly shorter SVL [snout-vent length (mm)] with significantly increased body condition, among other time-dependent effects. Our data suggest that larval exposure to PFAS can continue to impact growth in the juvenile stage after exposure has ended. Contrary to predictions, GenX affected terrestrial performance more consistently than its legacy congener, PFOA. Given the role of Bd in amphibian declines, further investigation of interactions of PFAS with Bd and other environmentally relevant pathogens is warranted.
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Affiliation(s)
- Evelyn M Barragan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tyler D Hoskins
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Elizabeth B Allmon
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jessica L McQuigg
- Department of Biology, Drew University, Madison, New Jersey 07940, United States
| | - Matthew T Hamilton
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Erin N Christian
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Grace S M Coogan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Catherine L Searle
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Youn Jeong Choi
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Linda S Lee
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Maria S Sepúlveda
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
- Sustainability Research Center and PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago 7550196, Chile
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Paetow LJ, Cue RI, Pauli BD, Marcogliese DJ. Effects of Herbicides and the Chytrid Fungus Batrachochytrium dendrobatidis on the growth, development and survival of Larval American Toads (Anaxyrus americanus). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 259:115021. [PMID: 37216860 DOI: 10.1016/j.ecoenv.2023.115021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 05/08/2023] [Accepted: 05/14/2023] [Indexed: 05/24/2023]
Abstract
Pesticides and pathogens adversely affect amphibian health, but their interactive effects are not well known. We assessed independent and combined effects of two agricultural herbicides and the fungal pathogen Batrachochytrium dendrobatidis (Bd) on the growth, development and survival of larval American toads (Anaxyrus americanus). Wild-caught tadpoles were exposed to four concentrations of atrazine (0.18, 1.8, 18.0, 180 μg/L) or glyphosate (7, 70, 700, 7000 µg a.e./L), respectively contained in Aatrex® Liquid 480 (Syngenta) or Vision® Silviculture Herbicide (Monsanto) for 14 days, followed by two doses of Bd. At day 14, atrazine had not affected survival, but it non-monotonically affected growth. Exposure to the highest concentration of glyphosate caused 100% mortality within 4 days, while lower doses had an increasing monotonic effect on growth. At day 65, tadpole survival was unaffected by atrazine and the lower doses of glyphosate. Neither herbicide demonstrated an interaction effect with Bd on survival, but exposure to Bd increased survival among both herbicide-exposed and herbicide-control tadpoles. At day 60, tadpoles exposed to the highest concentration of atrazine remained smaller than controls, indicating longer-term effects of atrazine on growth, but effects of glyphosate on growth disappeared. Growth was unaffected by any herbicide-fungal interaction but was positively affected by exposure to Bd following exposure to atrazine. Atrazine exhibited a slowing and non-monotonic effect on Gosner developmental stage, while exposure to Bd tended to speed up development and act antagonistically toward the observed effect of atrazine. Overall, atrazine, glyphosate and Bd all showed a potential to modulate larval toad growth and development.
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Affiliation(s)
- Linda J Paetow
- Department of Biology, Concordia University, 7141 Sherbrooke St. W, Montreal, Quebec H4B 1R6, Canada.
| | - Roger I Cue
- Department of Animal Science, McGill University, 21111 Lakeshore Rd., Ste. Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | - Bruce D Pauli
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1A 0H3, Canada
| | - David J Marcogliese
- Aquatic Contaminants Research Division, Water Science and Technology Directorate, Science and Technology Branch, St. Lawrence Centre, Environment and Climate Change Canada, 105 McGill, 7th Floor, Montreal, Quebec H2Y 2E7, Canada
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Supekar SC, Gramapurohit NP. Does atrazine induce changes in predator recognition, growth, morphology, and metamorphic traits of larval skipper frogs (Euphlyctis cyanophlyctis)? JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:125-137. [PMID: 36245429 DOI: 10.1002/jez.2661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/20/2022] [Accepted: 09/16/2022] [Indexed: 11/07/2022]
Abstract
Atrazine, an info disruptor, interferes with the olfaction of aquatic organisms by impairing the chemosensory system. Consequently, it affects behavior, physiology, and growth increases mortality and infections, and suppresses the immune system of aquatic animals. In this study, we wanted to determine the sensitivity of larval Euphlyctis cyanophlyctis to different concentrations of atrazine by assessing their antipredator behavior, growth, morphology, and metamorphic traits. The results indicate that exposure to atrazine did not affect the survival of tadpoles. However, it caused retarded growth at higher concentrations. Interestingly, the antipredator behavior of tadpoles toward conspecific alarm cues decreased in a dose-dependent manner with an increase in the concentration of atrazine. Tadpoles exposed to low concentrations of atrazine had deeper, wider bodies and tails while those exposed to higher concentrations had shallower and narrower bodies with shallower tail muscles. However, at low and moderate concentrations atrazine did not affect size at metamorphosis, it extended the larval duration at higher concentrations.
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Amphibian Dispersal Traits Not Impacted by Triclopyr Exposure during the Juvenile Stage. DIVERSITY 2023. [DOI: 10.3390/d15020215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Exposure to agrochemicals can have lethal and sublethal effects on amphibians. Most toxicology studies only examine exposure during the aquatic larval stage. Survival of the juvenile stage is the most important for population persistence and it is critical to understand the potential impacts of exposure during this life stage. We investigated how short-term exposure to triclopyr, an herbicide commonly used in forestry management, might impact several juvenile traits. To determine if juveniles perceived exposure as an environmental stressor, we measured their release of corticosterone. We also examined dispersal traits by measuring foraging and hopping behavior. We found no evidence that exposure negatively impacted these traits or was a stressor. Our results provide a preliminary assessment of the potential impact of triclopyr on juvenile amphibians, but we recommend additional research on the effects of agrochemicals on juvenile amphibians.
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Burgos-Aceves MA, Faggio C, Betancourt-Lozano M, González-Mille DJ, Ilizaliturri-Hernández CA. Ecotoxicological perspectives of microplastic pollution in amphibians. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2022; 25:405-421. [PMID: 36351281 DOI: 10.1080/10937404.2022.2140372] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Microplastics (MPs) are contaminants widely distributed in the environment and biota. Previously, most studies focused on identifying and characterizing microplastics in the marine environment, while their impact on freshwater ecosystems remains to be determined. This review summarizes recent findings regarding MPs physiological, immunological, and genetic effects on amphibians based upon the biological relevance of this species as indicators of freshwater pollution. Data demonstrated that MPs contamination may potentially alter various physiological processes in aquatic animals, mainly in the embryonic stages. It is worthwhile noting that adverse effects might be enhanced in synergy with other pollutants. However, amphibians might counteract the effect of MPs and other pollutants through microbiota present both in the intestine and on the skin. In addition, amphibian microbial composition might also be altered by MPs themselves in a manner that leads to unpredicted health consequences in amphibians.
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Affiliation(s)
- Mario A Burgos-Aceves
- Centro de Investigación Aplicada en Ambiente y Salud (CIAAS), CIACyT, Facultad de Medicina. Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - Caterina Faggio
- Department of Chemical, Biological, Pharmaceutical, and Environmental Sciences, University of Messina, Viale F. Stagno d'Alcontres, 31, Messina, Italy
| | | | - Donají J González-Mille
- Programa Cátedras del Consejo Nacional de Ciencia y Tecnología (CONACyT). Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - César A Ilizaliturri-Hernández
- Centro de Investigación Aplicada en Ambiente y Salud (CIAAS), CIACyT, Facultad de Medicina. Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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Smalling KL, Mosher BA, Iwanowicz LR, Loftin KA, Boehlke A, Hladik ML, Muletz-Wolz CR, Córtes-Rodríguez N, Femmer R, Campbell Grant EH. Site- and Individual-Level Contaminations Affect Infection Prevalence of an Emerging Infectious Disease of Amphibians. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:781-791. [PMID: 35040181 DOI: 10.1002/etc.5291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/29/2021] [Accepted: 01/09/2022] [Indexed: 06/14/2023]
Abstract
Emerging infectious disease outbreaks are one of multiple stressors responsible for amphibian declines globally. In the northeastern United States, ranaviral diseases are prevalent in amphibians and other ectothermic species, but there is still uncertainty as to whether their presence is leading to population-level effects. Further, there is also uncertainty surrounding the potential interactions among disease infection prevalence in free-ranging animals and habitat degradation (co-occurrence of chemical stressors). The present study was designed to provide field-based estimates of the relationship between amphibian disease and chemical stressors. We visited 40 wetlands across three protected areas, estimated the prevalence of ranavirus among populations of larval wood frogs and spotted salamanders, and assessed chemical and biological stressors in wetland habitats and larval amphibians using a suite of selected bioassays, screening tools, and chemical analyses. Ranavirus was detected on larval amphibians from each protected area with an estimated occupancy ranging from 0.27 to 0.55. Considerable variation in ranavirus occupancy was also observed within and among each protected area. Of the stressors evaluated, ranavirus prevalence was strongly and positively related to concentrations of metalloestrogens (metals with the potential to bind to estrogen receptors) and total metals in wetland sediments and weakly and negatively related to total pesticide concentrations in larval amphibians. These results can be used by land managers to refine habitat assessments to include such environmental factors with the potential to influence disease susceptibility. Environ Toxicol Chem 2022;41:781-791. © 2022 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Kelly L Smalling
- New Jersey Water Science Center, US Geological Survey, Lawrenceville, New Jersey, USA
| | - Brittany A Mosher
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, USA
| | - Luke R Iwanowicz
- Eastern Ecological Science Center at Leetown, US Geological Survey, Kearneysville, West Virginia, USA
| | - Keith A Loftin
- Kansas Water Science Center, US Geological Survey, Lawrence, Kansas, USA
| | - Adam Boehlke
- Geology, Geochemistry and Geophysics Science Center, US Geological Survey, Denver, Colorado, USA
| | - Michelle L Hladik
- California Water Science Center, US Geological Survey, Sacramento, California, USA
| | - Carly R Muletz-Wolz
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Nandadevi Córtes-Rodríguez
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
- Department of Biological Sciences, Ithaca College, Ithaca, New York, USA
| | - Robin Femmer
- Kansas Water Science Center, US Geological Survey, Lawrence, Kansas, USA
| | - Evan H Campbell Grant
- Eastern Ecological Science Center, S.O. Conte Anadromous Fish Research Laboratory, US Geological Survey, Turner Falls, Massachusetts, USA
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13
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Bosch J, Thumsová B, López-Rojo N, Pérez J, Alonso A, Fisher MC, Boyero L. Microplastics increase susceptibility of amphibian larvae to the chytrid fungus Batrachochytrium dendrobatidis. Sci Rep 2021; 11:22438. [PMID: 34789869 PMCID: PMC8599647 DOI: 10.1038/s41598-021-01973-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 11/08/2021] [Indexed: 11/09/2022] Open
Abstract
Microplastics (MPs), a new class of pollutants that pose a threat to aquatic biodiversity, are of increasing global concern. In tandem, the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causing the disease chytridiomycosis is emerging worldwide as a major stressor to amphibians. We here assess whether synergies exist between this infectious disease and MP pollution by mimicking natural contact of a highly susceptible species (midwife toads, Alytes obstetricans) with a Bd-infected reservoir species (fire salamanders, Salamandra salamandra) in the presence and absence of MPs. We found that MP ingestion increases the burden of infection by Bd in a dose-dependent manner. However, MPs accumulated to a greater extent in amphibians that were not exposed to Bd, likely due to Bd-damaged tadpole mouthparts interfering with MP ingestion. Our experimental approach showed compelling interactions between two emergent processes, chytridiomycosis and MP pollution, necessitating further research into potential synergies between these biotic and abiotic threats to amphibians.
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Affiliation(s)
- Jaime Bosch
- Biodiversity Research Institute, University of Oviedo-Principality of Asturias-CSIC, Mieres, Spain. .,Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, Rascafría, Spain. .,Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain.
| | - Barbora Thumsová
- Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain.,Asociación Herpetológica Española, Madrid, Spain
| | - Naiara López-Rojo
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain.,Laboratoire d'Ecologie Alpine (LECA), Université Grenoble Alpes, UMR CNRS-UGA-USMB, Grenoble, France
| | - Javier Pérez
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Alberto Alonso
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial School of Public Health, London, UK
| | - Luz Boyero
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Leioa, Spain.,IKERBASQUE, Bilbao, Spain
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14
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Urbina J, Bredeweg EM, Blaustein AR, Garcia TS. Direct and Latent Effects of Pathogen Exposure Across Native and Invasive Amphibian Life Stages. Front Vet Sci 2021; 8:732993. [PMID: 34778428 PMCID: PMC8585985 DOI: 10.3389/fvets.2021.732993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
Emerging infectious diseases are one of the multiple factors contributing to the current "biodiversity crisis". As part of the worldwide biodiversity crisis, amphibian populations are declining globally. Chytridiomycosis, an emerging infectious disease, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is a major cause of amphibian population declines. This fungus primarily affects keratinized structures in larval, juvenile, and adult amphibians as well as heart function. However, we know little about how Bd can impact embryos as well as potential latent effects of Bd exposure over ontogeny. Using two different Bd strains and multiple exposure times, we examined the effects of Bd exposure in Pacific chorus frog (Pseudacris regilla), Western toad (Anaxyrus boreas) and American bullfrog (Lithobates catesbeianus) life stages. Using a factorial experimental design, embryos of these three species were exposed to Bd at early and late embryonic stages, with some individuals re-exposed after hatching. Embryonic Bd exposure resulted in differential survival as a function of host species, Bd strain and timing of exposure. P. regilla experienced embryonic mortality when exposed during later developmental stages to one Bd strain. There were no differences across the treatments in embryonic mortality of A. boreas and embryonic mortality of L. catesbeianus occurred in all Bd exposure treatments. We detected latent effects in A. boreas and L. catesbeianus larvae, as mortality increased when individuals had been exposed to any of the Bd strains during the embryonic stage. We also detected direct effects on larval mortality in all three anuran species as a function of Bd strain, and when individuals were double exposed (late in the embryonic stage and again as larvae). Our results suggest that exposure to Bd can directly affect embryo survival and has direct and latent effects on larvae survival of both native and invasive species. However, these impacts were highly context dependent, with timing of exposure and Bd strain influencing the severity of the effects.
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Affiliation(s)
- Jenny Urbina
- Environmental Sciences Graduate Program, Oregon State University, Corvallis, OR, United States
| | - Evan M Bredeweg
- Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, OR, United States
| | - Andrew R Blaustein
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States
| | - Tiffany S Garcia
- Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, OR, United States
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15
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Zhao Q, Huang M, Liu Y, Wan Y, Duan R, Wu L. Effects of atrazine short-term exposure on jumping ability and intestinal microbiota diversity in male Pelophylax nigromaculatus adults. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:36122-36132. [PMID: 33683588 DOI: 10.1007/s11356-021-13234-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Atrazine, a common chemical pesticide, has toxicity to adult and juvenile amphibians in natural ecosystems; however, it is more common to study its effects on larvae instead of adults. This study assessed the impacts of atrazine in water through short-term exposure (7 days) on male black spotted frog (Pelophylax nigromaculatus) adults fed every day. The jumping ability, including jumping height, distance, time, and speed, was measured by 3D motion analysis software, and the intestinal content microbiota was determined by 16S rRNA amplicon sequencing with QIIME software. The results showed that male P. nigromaculatus exposure to 200 and 500 μg/L atrazine significantly increased jumping distance and jumping time compared to control groups. Conversely, 500 μg/L atrazine treatments significantly decreased the diversity and changed the composition and structure of intestinal content microflora in male P. nigromaculatus compared to control groups. At the phylum level, Chlamydiae was only detected in the control group, and Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were the dominant microflora in the atrazine treatment groups. At the genus level, the abundance of Lactobacillus and Weissella significantly increased in atrazine treatment groups compared to control groups. This study can provide a new framework based on movement behavior and intestinal microbiota to evaluate the response of amphibians to short-term exposure to environmental pollution.
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Affiliation(s)
- Qiang Zhao
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Minyi Huang
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Yang Liu
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Yuyue Wan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China
| | - Renyan Duan
- College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, Hunan, China.
| | - Lianfu Wu
- Key Laboratory of Biodiversity Research and Ecological Conservation in Southwest Anhui Province, Anqing, 246011, Anhui, China
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16
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Rohr JR. The Atrazine Saga and its Importance to the Future of Toxicology, Science, and Environmental and Human Health. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1544-1558. [PMID: 33999476 DOI: 10.1002/etc.5037] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/12/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
The herbicide atrazine is one of the most commonly used, well studied, and controversial pesticides on the planet. Much of the controversy involves the effects of atrazine on wildlife, particularly amphibians, and the ethically questionable decision making of members of industry, government, the legal system, and institutions of higher education, in most cases in an effort to "bend science," defined as manipulating research to advance economic, political, or ideological ends. In this Critical Perspective I provide a timeline of the most salient events in the history of the atrazine saga, which includes a multimillion-dollar smear campaign, lawsuits, investigative reporting, accusation of impropriety against the US Environmental Protection Agency, and a multibillion-dollar transaction. I argue that the atrazine controversy must be more than just a true story of cover-ups, bias, and vengeance. It must be used as an example of how manufacturing uncertainty and bending science can be exploited to delay undesired regulatory decisions and how greed and conflicts of interest-situations where personal or organizational considerations have compromised or biased professional judgment and objectivity-can affect environmental and public health and erode trust in the discipline of toxicology, science in general, and the honorable functioning of societies. Most importantly, I offer several recommendations that should help to 1) prevent the history of atrazine from repeating itself, 2) enhance the credibility and integrity of science, and 3) enrich human and environmental health. Environ Toxicol Chem 2021;40:1544-1558. © 2021 SETAC.
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Affiliation(s)
- Jason R Rohr
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
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17
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Forsburg ZR, Guzman A, Gabor CR. Artificial light at night (ALAN) affects the stress physiology but not the behavior or growth of Rana berlandieri and Bufo valliceps. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 277:116775. [PMID: 33639600 DOI: 10.1016/j.envpol.2021.116775] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/03/2021] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
Artificial light at night (ALAN) alters the natural light dark patterns in ecosystems. ALAN can have a suite of effects on community structure and is a driver of evolutionary processes that influences a range of behavioral and physiological traits. Our understanding of possible effects of ALAN across species amphibians is lacking and research is warranted as ALAN could contribute to stress and declines of amphibian populations, particularly in urban areas. We tested the hypothesis that exposure to constant light or pulsed ALAN would physiologically stress Rio Grande leopard frog (Rana berlandieri) and Gulf Coast toad (Bufo valliceps) tadpoles. We reared tadpoles under constant or pulsed (on and off again) ALAN for 14 days and measured corticosterone release rates over time using a non-invasive water-borne hormone protocol. ALAN treatments did not affect behavior or growth. Tadpoles of both species had higher corticosterone (cort) release rates after 14 days of constant light exposure. Leopard frog tadpoles had lower cort release rates after exposure to pulsed ALAN while toad tadpoles had higher cort release rates. These results suggest that short-term exposure to constant or pulsed light at night may contribute to stress in tadpoles but that each species differentially modulated their cort response to ALAN exposure and a subsequent stressor. This flexibility in the upregulation and downregulation of hypothalamic-pituitary-interrenal axis response may indicate an alternative mechanism for diminishing the deleterious effects of chronic stress. Nonetheless, ALAN should be considered in management and conservation plans for amphibians.
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Affiliation(s)
- Zachery R Forsburg
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA.
| | - Alex Guzman
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA
| | - Caitlin R Gabor
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA
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18
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Ramsay C, Rohr JR. The application of community ecology theory to co-infections in wildlife hosts. Ecology 2021; 102:e03253. [PMID: 33222193 DOI: 10.1002/ecy.3253] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/27/2020] [Accepted: 09/18/2020] [Indexed: 11/11/2022]
Abstract
Priority effect theory, a foundational concept from community ecology, states that the order and timing of species arrival during species assembly can affect species composition. Although this theory has been applied to co-infecting parasite species, it has almost always been with a single time lag between co-infecting parasites. Thus, how the timing of parasite species arrival affects co-infections and disease remains poorly understood. To address this gap in the literature, we exposed postmetamorphic Cuban tree frogs (Osteopilus septentrionalis) to Ranavirus, the fungus Batrachochytrium dendrobatidis (Bd), a nematode Aplectana hamatospicula, or pairs of these parasites either simultaneously or sequentially at a range of time lags and quantified load of the secondary parasite and host growth, survival, and parasite tolerance. Prior exposure to Bd or A. hamatospicula significantly increased viral loads relative to hosts singly infected with Ranavirus, whereas A. hamatospicula loads in hosts were higher when coexposed to Bd than when coexposed to Ranavirus. There was a significant positive relationship between time since Ranavirus infection and Bd load, and prior exposure to A. hamatospicula decreased Bd loads compared to simultaneous co-infection with these parasites. Infections with Bd and Ranavirus either singly or in co-infections decreased host growth and survival. This research reveals that time lags between co-infections can affect parasite loads, in line with priority effects theory. As co-infections in the field are unlikely to be simultaneous, an understanding of when co-infections are impacted by time lags between parasite exposures may play a major role in controlling problematic co-infections.
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Affiliation(s)
- Chloe Ramsay
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556, USA
| | - Jason R Rohr
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556, USA
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19
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Preuss JF, Greenspan SE, Rossi EM, Lucas Gonsales EM, Neely WJ, Valiati VH, Woodhams DC, Becker CG, Tozetti AM. Widespread Pig Farming Practice Linked to Shifts in Skin Microbiomes and Disease in Pond-Breeding Amphibians. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11301-11312. [PMID: 32845628 DOI: 10.1021/acs.est.0c03219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Farming practices may reshape the structure of watersheds, water quality, and the health of aquatic organisms. Nutrient enrichment from agricultural pollution increases disease pressure in many host-pathogen systems, but the mechanisms underlying this pattern are not always resolved. For example, nutrient enrichment should strongly influence pools of aquatic environmental bacteria, which has the potential to alter microbiome composition of aquatic animals and their vulnerability to disease. However, shifts in the host microbiome have received little attention as a link between nutrient enrichment and diseases of aquatic organisms. We examined nutrient enrichment through the widespread practice of integrated pig-fish farming and its effects on microbiome composition of Brazilian amphibians and prevalence of the globally distributed amphibian skin pathogen Batrachochytrium dendrobatidis (Bd). This farming system drove surges in fecal coliform bacteria, disturbing amphibian skin bacterial communities such that hosts recruited higher proportions of Bd-facilitative bacteria and carried higher Bd prevalence. Our results highlight previously overlooked connections between global trends in land use change, microbiome dysbiosis, and wildlife disease. These interactions may be particularly important for disease management in the tropics, a region with both high biodiversity and continually intensifying anthropogenic pressures on aquatic wildlife habitats.
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Affiliation(s)
- Jackson F Preuss
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Eliandra M Rossi
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Elaine M Lucas Gonsales
- Departamento de Zootecnia e Ciências Biológicas, Universidade Federal de Santa Maria, RS 98300-000, Brazil
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Victor Hugo Valiati
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Alexandro M Tozetti
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
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20
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Cope KL, Schook MW, Benard MF. Exposure to artificial light at night during the larval stage has delayed effects on juvenile corticosterone concentration in American toads, Anaxyrus americanus. Gen Comp Endocrinol 2020; 295:113508. [PMID: 32442544 DOI: 10.1016/j.ygcen.2020.113508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 05/02/2020] [Accepted: 05/08/2020] [Indexed: 02/02/2023]
Abstract
Artificial Light At Night (ALAN) is an environmental stressor that can disrupt individual physiology and ecological interactions. Hormones such as corticosterone are often responsible for mediating an organism's response to environmental stressors. We investigated whether ALAN was associated with a corticosterone response and whether it exacerbated the effects of another common stressor, predation. We tested for consumptive, non-consumptive, and physiological effects of ALAN and predator presence (dragonfly larvae) on a widespread amphibian, the American toad (Anaxyrus americanus). We found predators had consumptive (decreased survival) and non-consumptive (decreased growth) effects on larval toads. ALAN did not affect larval toads nor did it interact with the predator treatment to increase larval toad predation. Despite the consumptive and non-consumptive effects of predators, neither predators nor ALAN affected corticosterone concentration in the larval and metamorph life-stages. In contrast to studies in other organisms, we did not find any evidence that suggested ALAN alters predator-prey interactions between dragonfly larvae and toads. However, there was an inverse relationship between corticosterone and survival that was exacerbated by exposure to ALAN when predators were absent. Additionally, larval-stage exposure to ALAN increased corticosterone concentration in juvenile toads. Our results suggest the physiological effects of ALAN may not be demonstrated until later life-stages.
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Affiliation(s)
- Kacey L Cope
- Department of Biology, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44016, USA.
| | - Mandi W Schook
- Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH 44109, USA; Disney's Animals, Science and Environment, 1200 East Savannah Circle, Bay Lake, FL, USA.
| | - Michael F Benard
- Department of Biology, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44016, USA.
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21
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Nataraj MBR, Krishnamurthy SVB. Individual and combined effects of organophosphate and carbamate pesticides on the cricket frog Fejervarya limnocharis. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2020; 42:1767-1774. [PMID: 31520318 DOI: 10.1007/s10653-019-00418-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Many amphibians use water bodies associated with agro-ecosystem for breeding and thus are exposed to multiple chemicals. Fejervarya limnocharis is a common frog occurring in rice paddy fields. The timings of pesticide application generally coincide with the tenure of the occurrence of tadpoles in shallow waters of paddy fields. Malathion and carbaryl are frequently used in rice paddy fields to control leafhoppers and rice bugs, respectively. Therefore, effects of mixtures of malathion and carbaryl insecticides on the survival of tadpoles and emergence of froglets of Fejervarya limnocharis were studied in the laboratory using combinations of three concentrations of carbaryl (0, 25, 50 µg l-1) with four concentrations of malathion (0, 100, 250, 500 µg l-1). Both malathion and carbaryl were found to be toxic to tadpoles. A reduction in tadpole survival and froglet emergence was recorded with increasing concentrations of carbaryl and malathion. We found significant interaction between carbaryl and malathion on tadpole survival and froglet emergence. Tadpoles exposed to combination of pesticides showed early emergence as froglets compared to control. The extent of toxicity and pesticide interactions are varied when mixed in different concentrations. The reduction in survival, froglet emergence and delay in emergence of metamorphs can occur in rice paddy field as both pesticides are used simultaneously. Therefore, combinations of pesticides may have significant negative effects on the frog population of agro-ecosystems, which requires further confirmation through appropriate field experiments.
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Affiliation(s)
- Makkimane Bhaskar Rao Nataraj
- Department of Environmental Science, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shimoga, Karnataka, 577 451, India
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22
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Jacquin L, Petitjean Q, Côte J, Laffaille P, Jean S. Effects of Pollution on Fish Behavior, Personality, and Cognition: Some Research Perspectives. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00086] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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23
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Forsburg ZR, Goff CB, Perkins HR, Robicheaux JA, Almond GF, Gabor CR. Validation of water-borne cortisol and corticosterone in tadpoles: Recovery rate from an acute stressor, repeatability, and evaluating rearing methods. Gen Comp Endocrinol 2019; 281:145-152. [PMID: 31199927 DOI: 10.1016/j.ygcen.2019.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/21/2019] [Accepted: 06/10/2019] [Indexed: 12/23/2022]
Abstract
Amphibian populations are declining globally, so understanding how individuals respond to anthropogenic and environmental stressors may aid conservation efforts. Using a non-invasive water-borne hormone assay, we measured the release rates of two glucocorticoid hormones, corticosterone and cortisol, in Rio Grande Leopard frog, Rana berlandieri, tadpoles. We validated this method pharmacologically and biologically using an adrenocorticotropic hormone (ACTH) challenge, exposure to exogenous corticosterone, and an agitation test. We calculated the repeatability of hormone release rates, the recovery time from an acute stressor, and explored rearing methods for tadpoles. Tadpole corticosterone release rates increased following an ACTH challenge, exposure to exogenous corticosterone, and agitation, validating the use of water-borne hormone methods in this species. After exposure to an acute stressor via agitation, corticosterone release rates began to decline after 2 h and were lowest after 6 h, suggesting a relatively rapid recovery from an acute stressor. Tadpoles reared in groups had higher corticosterone release rates than tadpoles reared individually, and lost mass by Day 7, while tadpoles reared individually did not show a stress response, therefore either rearing method is viable, but have differing physiological costs for tadpoles. Repeatability of corticosterone release rates was moderate to high in R. berlandieri tadpoles, indicating that this species can show a response to selection and potentially respond to rapid environmental change. Our results show that the water-borne hormone assay is a viable way to measure glucocorticoids in this species and is useful in the field of conservation physiology for rare and endangered species.
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Affiliation(s)
- Zachery R Forsburg
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States.
| | - Cory B Goff
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States
| | - Hannah R Perkins
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States
| | - Joseph A Robicheaux
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States
| | - Grayson F Almond
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States
| | - Caitlin R Gabor
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666 United States
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24
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Rohr JR, Barrett CB, Civitello DJ, Craft ME, Delius B, DeLeo GA, Hudson PJ, Jouanard N, Nguyen KH, Ostfeld RS, Remais JV, Riveau G, Sokolow SH, Tilman D. Emerging human infectious diseases and the links to global food production. NATURE SUSTAINABILITY 2019; 2:445-456. [PMID: 32219187 PMCID: PMC7091874 DOI: 10.1038/s41893-019-0293-3] [Citation(s) in RCA: 230] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 04/17/2019] [Indexed: 05/07/2023]
Abstract
Infectious diseases are emerging globally at an unprecedented rate while global food demand is projected to increase sharply by 2100. Here, we synthesize the pathways by which projected agricultural expansion and intensification will influence human infectious diseases and how human infectious diseases might likewise affect food production and distribution. Feeding 11 billion people will require substantial increases in crop and animal production that will expand agricultural use of antibiotics, water, pesticides and fertilizer, and contact rates between humans and both wild and domestic animals, all with consequences for the emergence and spread of infectious agents. Indeed, our synthesis of the literature suggests that, since 1940, agricultural drivers were associated with >25% of all - and >50% of zoonotic - infectious diseases that emerged in humans, proportions that will likely increase as agriculture expands and intensifies. We identify agricultural and disease management and policy actions, and additional research, needed to address the public health challenge posed by feeding 11 billion people.
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Affiliation(s)
- Jason R. Rohr
- Department of Biological Sciences, Eck Institute for Global Health, and Environmental Change Initiative, University of Notre Dame, Notre Dame, IN USA
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | | | | | - Meggan E. Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN USA
| | - Bryan Delius
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | - Giulio A. DeLeo
- Department of Biology and Woods Institute for the Environment, Hopkins Marine Station, Stanford University, Pacific Grove, CA USA
| | - Peter J. Hudson
- Center for Infectious Disease Dynamics, Pennsylvania State University, College Station, PA USA
| | - Nicolas Jouanard
- Laboratoire de Recherches Biomédicales, Espoir pour la Santé, Saint-Louis, Senegal
| | - Karena H. Nguyen
- Department of Integrative Biology, University of South Florida, Tampa, FL USA
| | | | - Justin V. Remais
- Division of Environmental Health Sciences, University of California, Berkeley, Berkeley, CA USA
| | - Gilles Riveau
- Laboratoire de Recherches Biomédicales, Espoir pour la Santé, Saint-Louis, Senegal
| | - Susanne H. Sokolow
- Department of Biology and Woods Institute for the Environment, Hopkins Marine Station, Stanford University, Pacific Grove, CA USA
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA USA
| | - David Tilman
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN USA
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25
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Gavel MJ, Richardson SD, Dalton RL, Soos C, Ashby B, McPhee L, Forbes MR, Robinson SA. Effects of 2 Neonicotinoid Insecticides on Blood Cell Profiles and Corticosterone Concentrations of Wood Frogs (Lithobates sylvaticus). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:1273-1284. [PMID: 30901102 DOI: 10.1002/etc.4418] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/19/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
Neonicotinoids are widely used insecticides that are detectable in agricultural waterways. These insecticides are of concern due to their potential impacts on nontarget organisms. Pesticides can affect development of amphibians and suppress the immune system, which could impact disease susceptibility and tolerance. No previous studies on amphibians have examined the effects of these insecticides on differential blood cell proportions or concentrations of corticosterone (a general stress hormone). We investigated the effects of chronic exposure to 2 neonicotinoids, thiamethoxam and clothianidin, on immunometrics of wood frogs (Lithobates sylvaticus). Frogs were exposed to single, chronic treatments of 2.5 or 250 µg/L of clothianidin or thiamethoxam for 7 wk from Gosner stages 25 to 46. The juvenile frogs were then maintained for 3 wk post metamorphosis without exposure to neonicotinoids. We measured water-borne corticosterone twice: at 6 d and 8 wk after exposure in larval and juvenile frogs, respectively. We assessed differential blood cell profiles from juvenile frogs. Corticosterone was significantly lower in tadpoles exposed to 250 µg/L of thiamethoxam compared with other tadpole treatments, but no significant differences in corticosterone concentrations were found in treatments using juvenile frogs. Anemia was detected in all treatments compared with controls with the exception of tadpoles exposed to 2.5 µg/L of clothianidin. Neutrophil-to-leukocyte and neutrophil-to-lymphocyte ratios were elevated in frogs exposed to 250 µg/L of thiamethoxam. Collectively, these results indicate that chronic exposure to neonicotinoids has varied impacts on blood cell profiles and corticosterone concentrations of developing wood frogs, which are indicative of stress. Future studies should investigate whether exposure to neonicotinoids increases susceptibility to infection by parasites in both larval and adult wood frogs. Environ Toxicol Chem 2019;38:1273-1284. © 2019 Crown in the right of Canada. Published by Wiley Periodicals Inc. on behalf of SETAC.
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Affiliation(s)
- Melody J Gavel
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | | | - Rebecca L Dalton
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
- Science and Technology Branch, Science and Risk Assessment Directorate, Ecological Assessment Division, Environment and Climate Change Canada, Gatineau, Quebec, Canada
| | - Catherine Soos
- Science and Technology Branch, Wildlife and Landscape Science Directorate, Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
- Department of Veterinary Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Brendan Ashby
- Science and Technology Branch, Wildlife and Landscape Science Directorate, Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Landon McPhee
- Science and Technology Branch, Wildlife and Landscape Science Directorate, Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Mark R Forbes
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Stacey A Robinson
- Science and Technology Branch, Wildlife and Landscape Science Directorate, Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Ottawa, Ontario, Canada
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26
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Gabor CR, Perkins HR, Heitmann AT, Forsburg ZR, Aspbury AS. Roundup™ With Corticosterone Functions as an Infodisruptor to Antipredator Response in Tadpoles. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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27
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Martin LB, Vitousek M, Donald JW, Flock T, Fuxjager MJ, Goymann W, Hau M, Husak J, Johnson MA, Kircher B, Knapp R, Miller ET, Schoenle LA, Williams T, Francis CD. IUCN Conservation Status Does Not Predict Glucocorticoid Concentrations in Reptiles and Birds. Integr Comp Biol 2019; 58:800-813. [PMID: 30052988 DOI: 10.1093/icb/icy102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Circulating glucocorticoids (GCs) are the most commonly used biomarkers of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether International Union for the Conservation of Nature (IUCN) listing status (concern versus no obvious concern) and/or location within a geographic range (edge versus non-edge) predicted baseline and post-restraint concentrations of corticosterone (CORT) among many species of birds and reptiles. Even though such an approach can be viewed as coarse, we asked in this analysis whether CORT concentrations might be useful to implicate species at risk. Indeed, our effort, relying on HormoneBase, a repository of data on wildlife steroids, complements several other large-scale efforts in this issue to describe and understand GC variation. Using a phylogenetically informed Bayesian approach, we found little evidence that either IUCN status or edge/non-edge location in a geographic distribution were related to GC levels. However, we did confirm patterns described in previous studies, namely that breeding condition and evolutionary relatedness among species predicted some GC variation. Given the broad scope of our work, we are reluctant to conclude that IUCN status and location within a range are unrelated to GC regulation. We encourage future more targeted efforts on GCs in at-risk populations to reveal how factors leading to IUCN listing or the environmental conditions at range edges impact individual performance and fitness, particularly in the mammals, amphibians, and fish species we could not study here because data are currently unavailable.
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Affiliation(s)
- Lynn B Martin
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Maren Vitousek
- Cornell Lab of Ornithology, Ithaca, NY 14850, USA.,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jeremy W Donald
- Coates Library, Trinity University, San Antonio, TX 78212, USA
| | - Travis Flock
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Matthew J Fuxjager
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | | | - Michaela Hau
- Max Planck Institute for Ornithology, 82319 Starnberg, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Jerry Husak
- Department of Biology, University of St. Thomas, St. Paul, MN 55105, USA
| | - Michele A Johnson
- Department of Biology, Trinity University, San Antonio, TX 78212, USA
| | - Bonnie Kircher
- Department of Biology, University of Florida, Gainesville, FL 32608, USA
| | - Rosemary Knapp
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | | | - Laura A Schoenle
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA.,Department of Biology, Hamilton College, Clinton, NY 13323, USA
| | - Tony Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Clinton D Francis
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
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28
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Zubrod JP, Bundschuh M, Arts G, Brühl CA, Imfeld G, Knäbel A, Payraudeau S, Rasmussen JJ, Rohr J, Scharmüller A, Smalling K, Stehle S, Schulz R, Schäfer RB. Fungicides: An Overlooked Pesticide Class? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3347-3365. [PMID: 30835448 PMCID: PMC6536136 DOI: 10.1021/acs.est.8b04392] [Citation(s) in RCA: 277] [Impact Index Per Article: 55.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 12/14/2018] [Accepted: 03/05/2019] [Indexed: 05/23/2023]
Abstract
Fungicides are indispensable to global food security and their use is forecasted to intensify. Fungicides can reach aquatic ecosystems and occur in surface water bodies in agricultural catchments throughout the entire growing season due to their frequent, prophylactic application. However, in comparison to herbicides and insecticides, the exposure to and effects of fungicides have received less attention. We provide an overview of the risk of fungicides to aquatic ecosystems covering fungicide exposure (i.e., environmental fate, exposure modeling, and mitigation measures) as well as direct and indirect effects of fungicides on microorganisms, macrophytes, invertebrates, and vertebrates. We show that fungicides occur widely in aquatic systems, that the accuracy of predicted environmental concentrations is debatable, and that fungicide exposure can be effectively mitigated. We additionally demonstrate that fungicides can be highly toxic to a broad range of organisms and can pose a risk to aquatic biota. Finally, we outline central research gaps that currently challenge our ability to predict fungicide exposure and effects, promising research avenues, and shortcomings of the current environmental risk assessment for fungicides.
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Affiliation(s)
- Jochen P. Zubrod
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
- Eußerthal
Ecosystem Research Station, University of
Koblenz-Landau, Birkenthalstraße
13, D-76857 Eußerthal, Germany
| | - Mirco Bundschuh
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
- Department
of Aquatic Sciences and Assessment, Swedish
University of Agricultural Sciences, Lennart Hjelms väg 9, SWE-75007 Uppsala, Sweden
| | - Gertie Arts
- Wageningen
Environmental Research, Wageningen University
and Research, Wageningen, The Netherlands
| | - Carsten A. Brühl
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
| | - Gwenaël Imfeld
- Laboratoire
d’Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/ENGEES, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
| | - Anja Knäbel
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
| | - Sylvain Payraudeau
- Laboratoire
d’Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/ENGEES, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
| | - Jes J. Rasmussen
- Aarhus
University, Dept. of Bioscience, Vejlsoevej 25, 8600 Silkeborg, Denmark
| | - Jason Rohr
- University
of South Florida, Department of Integrative
Biology, Tampa, Florida, United States
- Department
of Biological Sciences, Environmental Change Initiative, and Eck Institute
for Global Health, University of Notre Dame, Notre Dame, Indiana, United
States
| | - Andreas Scharmüller
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
| | - Kelly Smalling
- U.S.
Geological Survey, New Jersey Water Science
Center, Lawrenceville, New Jersey, United States
| | - Sebastian Stehle
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
- Eußerthal
Ecosystem Research Station, University of
Koblenz-Landau, Birkenthalstraße
13, D-76857 Eußerthal, Germany
| | - Ralf Schulz
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
- Eußerthal
Ecosystem Research Station, University of
Koblenz-Landau, Birkenthalstraße
13, D-76857 Eußerthal, Germany
| | - Ralf B. Schäfer
- Institute
for Environmental Sciences, University of
Koblenz-Landau, Fortstraße
7, D-76829 Landau, Germany
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29
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Cohen JM, Civitello DJ, Venesky MD, McMahon TA, Rohr JR. An interaction between climate change and infectious disease drove widespread amphibian declines. GLOBAL CHANGE BIOLOGY 2019; 25:927-937. [PMID: 30484936 DOI: 10.1111/gcb.14489] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/02/2018] [Indexed: 06/09/2023]
Abstract
Climate change might drive species declines by altering species interactions, such as host-parasite interactions. However, few studies have combined experiments, field data, and historical climate records to provide evidence that an interaction between climate change and disease caused any host declines. A recently proposed hypothesis, the thermal mismatch hypothesis, could identify host species that are vulnerable to disease under climate change because it predicts that cool- and warm-adapted hosts should be vulnerable to disease at unusually warm and cool temperatures, respectively. Here, we conduct experiments on Atelopus zeteki, a critically endangered, captively bred frog that prefers relatively cool temperatures, and show that frogs have high pathogen loads and high mortality rates only when exposed to a combination of the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) and high temperatures, as predicted by the thermal mismatch hypothesis. Further, we tested various hypotheses to explain recent declines experienced by species in the amphibian genus Atelopus that are thought to be associated with B. dendrobatidis and reveal that these declines are best explained by the thermal mismatch hypothesis. As in our experiments, only the combination of rapid increases in temperature and infectious disease could account for the patterns of declines, especially in species adapted to relatively cool environments. After combining experiments on declining hosts with spatiotemporal patterns in the field, our findings are consistent with the hypothesis that widespread species declines, including possible extinctions, have been driven by an interaction between increasing temperatures and infectious disease. Moreover, our findings suggest that hosts adapted to relatively cool conditions will be most vulnerable to the combination of increases in mean temperature and emerging infectious diseases.
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Affiliation(s)
- Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, Tampa, Florida
| | | | | | | | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, Florida
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30
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Larsen AE, Patton M, Martin EA. High highs and low lows: Elucidating striking seasonal variability in pesticide use and its environmental implications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:828-837. [PMID: 30253365 DOI: 10.1016/j.scitotenv.2018.09.206] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/11/2018] [Accepted: 09/16/2018] [Indexed: 06/08/2023]
Abstract
Despite substantial public and scientific concern regarding unintended environmental and health consequences of agricultural pesticide use, identifying when and where high levels of use occur is stymied by a dearth of data at biologically relevant spatial or temporal scales. Here we investigate intra-annual patterns in pesticide use by crop and by pesticide type using unique pesticide use data from agriculturally diverse croplands of California, USA. We find that timing and type of pesticide use is strongly crop-dependent, and that for many high pesticide use crops, monthly application rates are highly consistent from year-to-year. Further, while pesticide use hotspots are concentrated in early summer, regions with very high use occur throughout the year with spatial distributions varying therein. The enormity of intra-annual variation in pesticide use, as well as the consistency in those patterns through time, suggests opportunities for crop-specific pest management and region-specific mitigation approaches to limit environmental and human health hazards from agricultural pesticide use.
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Affiliation(s)
- Ashley E Larsen
- Bren School of Environmental Science & Management, University of California, Santa Barbara, United States of America.
| | - Michael Patton
- Bren School of Environmental Science & Management, University of California, Santa Barbara, United States of America
| | - Emily A Martin
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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31
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Rumschlag SL, Boone MD. High juvenile mortality in amphibians during overwintering related to fungal pathogen exposure. DISEASES OF AQUATIC ORGANISMS 2018; 131:13-28. [PMID: 30324911 DOI: 10.3354/dao03277] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The result of pathogen exposures may depend upon trade-offs in energetic demands for immune responses against host growth and survival. Environmental conditions may influence these trade-offs by affecting host size, or trade-offs may change across seasons, altering impacts of pathogens. We exposed northern leopard frog Lithobates pipiens tadpoles to different larval environments (low leaf litter, high density of conspecifics, atrazine, caged fish, or controls) that influenced size at metamorphosis. Subsequently, we exposed metamorphs to Batrachochytrium dendrobatidis (Bd), a fungal pathogen, just after metamorphosis and/or prior to overwintering 12 wk later. Bd exposure dramatically reduced survival during overwintering, with the strongest effects when hosts were exposed at both time points. Larval environments resulted in differences in host size. Those exposed to caged fish were 2.5 times larger than the smallest (those exposed to high density of conspecifics), but larval environment did not influence Bd effects on growth and survival. The largest frogs exposed to caged fish had greater survival through overwintering, but in the absence of Bd. We built stage-structured models to evaluate if overwinter mortality from Bd is capable of having effects on host populations. Our models suggest that Bd exposure after metamorphosis or before overwintering can reduce population growth rates. Our study demonstrates that hosts suffer little effects of Bd exposures following metamorphosis and that small body size did not hamper growth and survival. Instead, we provide evidence that winter mortality from Bd exposure is capable of reducing population sizes, providing a plausible mechanism for amphibian declines in temperate regions.
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32
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Effects of Emerging Infectious Diseases on Amphibians: A Review of Experimental Studies. DIVERSITY-BASEL 2018. [DOI: 10.3390/d10030081] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Numerous factors are contributing to the loss of biodiversity. These include complex effects of multiple abiotic and biotic stressors that may drive population losses. These losses are especially illustrated by amphibians, whose populations are declining worldwide. The causes of amphibian population declines are multifaceted and context-dependent. One major factor affecting amphibian populations is emerging infectious disease. Several pathogens and their associated diseases are especially significant contributors to amphibian population declines. These include the fungi Batrachochytrium dendrobatidis and B. salamandrivorans, and ranaviruses. In this review, we assess the effects of these three pathogens on amphibian hosts as found through experimental studies. Such studies offer valuable insights to the causal factors underpinning broad patterns reported through observational studies. We summarize key findings from experimental studies in the laboratory, in mesocosms, and from the field. We also summarize experiments that explore the interactive effects of these pathogens with other contributors of amphibian population declines. Though well-designed experimental studies are critical for understanding the impacts of disease, inconsistencies in experimental methodologies limit our ability to form comparisons and conclusions. Studies of the three pathogens we focus on show that host susceptibility varies with such factors as species, host age, life history stage, population and biotic (e.g., presence of competitors, predators) and abiotic conditions (e.g., temperature, presence of contaminants), as well as the strain and dose of the pathogen, to which hosts are exposed. Our findings suggest the importance of implementing standard protocols and reporting for experimental studies of amphibian disease.
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33
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Cross-Life Stage Effects of Aquatic Larval Density and Terrestrial Moisture on Growth and Corticosterone in the Spotted Salamander. DIVERSITY 2018. [DOI: 10.3390/d10030068] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
For organisms with complex life cycles, conditions experienced during early life stages may constrain later growth and survival. Conversely, compensatory mechanisms may attenuate negative effects from early life stages. We used the spotted salamander, Ambystoma maculatum, to test how aquatic larval density and terrestrial moisture influence juvenile growth, food intake, evaporative water loss and water reuptake rates, and corticosterone levels. We conducted an outdoor mesocosm experiment to manipulate larval density and transferred metamorphosed salamanders into low and high terrestrial moisture treatments in laboratory terrariums. After the larval stage, high-density salamanders were significantly smaller and had higher corticosterone release rates than those from low-density treatments. Salamanders in the low terrestrial moisture treatment consumed fewer roaches, had lower mass-specific growth rates, higher water reuptake, and higher corticosterone release rates than salamanders in high terrestrial moisture treatments. Across moisture treatments, smaller salamanders had higher mass-specific growth rates than larger salamanders. Our results suggest that salamanders can partially compensate for competition in the larval aquatic habitat with increased growth as juveniles, but this response is dependent on terrestrial habitat quality. Thus, the persistence of early life stage effects can be an important, yet context-dependent, component of amphibian life cycles.
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34
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Dananay KL, Benard MF. Artificial light at night decreases metamorphic duration and juvenile growth in a widespread amphibian. Proc Biol Sci 2018; 285:20180367. [PMID: 30051829 PMCID: PMC6053935 DOI: 10.1098/rspb.2018.0367] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/11/2018] [Indexed: 12/31/2022] Open
Abstract
Artificial light at night (ALAN) affects over 20% of the earth's surface and is estimated to increase 6% per year. Most studies of ALAN have focused on a single mechanism or life stage. We tested for indirect and direct ALAN effects that occurred by altering American toads' (Anaxyrus americanus) ecological interactions or by altering toad development and growth, respectively. We conducted an experiment over two life stages using outdoor mesocosms and indoor terraria. In the first phase, the presence of ALAN reduced metamorphic duration and periphyton biomass. The effects of ALAN appeared to be mediated through direct effects on toad development, and we found no evidence for indirect effects of ALAN acting through altered ecological interactions or colonization. In the second phase, post-metamorphic toad growth was reduced by 15% in the ALAN treatment. Juvenile-stage ALAN also affected toad activity: in natural light, toads retreated into leaf litter at night whereas ALAN toads did not change behaviour. Carry-over effects of ALAN were also present; juvenile toads that had been exposed to larval ALAN exhibited marginally increased activity. In this time frame and system, our experiments suggested ALAN's effects act primarily through direct effects, rather than indirect effects, and can persist across life stages.
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Affiliation(s)
- Kacey L Dananay
- Department of Biology, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106-7080, USA
| | - Michael F Benard
- Department of Biology, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106-7080, USA
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35
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McCoy KA, Peralta AL. Pesticides Could Alter Amphibian Skin Microbiomes and the Effects of Batrachochytrium dendrobatidis. Front Microbiol 2018; 9:748. [PMID: 29731742 PMCID: PMC5919957 DOI: 10.3389/fmicb.2018.00748] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/03/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Krista A McCoy
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Ariane L Peralta
- Department of Biology, East Carolina University, Greenville, NC, United States
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36
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Proximity to parasites reduces host fitness independent of infection in a Drosophila-Macrocheles system. Parasitology 2018. [PMID: 29530103 DOI: 10.1017/s0031182018000379] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Parasites are known to have direct negative effects on host fitness; however, the indirect effects of parasitism on host fitness sans infection are less well understood. Hosts undergo behavioural and physiological changes when in proximity to parasites. Yet, there is little experimental evidence showing that these changes lead to long-term decreases in host fitness. We aimed to determine if parasite exposure affects host fitness independent of contact, because current approaches to parasite ecology may underestimate the effect of parasites on host populations. We assayed the longevity and reproductive output of Drosophila nigrospiracula exposed or not exposed to ectoparasitic Macrocheles subbadius. In order to preclude contact and infection, mites and flies were permanently separated with a mesh screen. Exposed flies had shorter lives and lower fecundity relative to unexposed flies. Recent work in parasite ecology has argued that parasite-host systems show similar processes as predator-prey systems. Our findings mirror the non-consumptive effects observed in predator-prey systems, in which prey species suffer reduced fitness even if they never come into direct contact with predators. Our results support the perspective that there are analogous effects in parasite-host systems, and suggest new directions for research in both parasite ecology and the ecology of fear.
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37
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Are the adverse effects of stressors on amphibians mediated by their effects on stress hormones? Oecologia 2017; 186:393-404. [DOI: 10.1007/s00442-017-4020-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 11/22/2017] [Indexed: 11/25/2022]
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38
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Rohr JR, Brown J, Battaglin WA, McMahon TA, Relyea RA. A pesticide paradox: fungicides indirectly increase fungal infections. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2290-2302. [PMID: 28763165 PMCID: PMC5711531 DOI: 10.1002/eap.1607] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 04/21/2017] [Accepted: 07/11/2017] [Indexed: 05/17/2023]
Abstract
There are many examples where the use of chemicals have had profound unintended consequences, such as fertilizers reducing crop yields (paradox of enrichment) and insecticides increasing insect pests (by reducing natural biocontrol). Recently, the application of agrochemicals, such as agricultural disinfectants and fungicides, has been explored as an approach to curb the pathogenic fungus, Batrachochytrium dendrobatidis (Bd), which is associated with worldwide amphibian declines. However, the long-term, net effects of early-life exposure to these chemicals on amphibian disease risk have not been thoroughly investigated. Using a combination of laboratory experiments and analysis of data from the literature, we explored the effects of fungicide exposure on Bd infections in two frog species. Extremely low concentrations of the fungicides azoxystrobin, chlorothalonil, and mancozeb were directly toxic to Bd in culture. However, estimated environmental concentrations of the fungicides did not reduce Bd on Cuban tree frog (Osteopilus septentrionalis) tadpoles exposed simultaneously to any of these fungicides and Bd, and fungicide exposure actually increased Bd-induced mortality. Additionally, exposure to any of these fungicides as tadpoles resulted in higher Bd abundance and greater Bd-induced mortality when challenged with Bd post-metamorphosis, an average of 71 d after their last fungicide exposure. Analysis of data from the literature revealed that previous exposure to the fungicide itraconazole, which is commonly used to clear Bd infections, made the critically endangered booroolong frog (Litoria booroolongensis) more susceptible to Bd. Finally, a field survey revealed that Bd prevalence was positively associated with concentrations of fungicides in ponds. Although fungicides show promise for controlling Bd, these results suggest that, if fungicides do not completely eliminate Bd or if Bd recolonizes, exposure to fungicides has the potential to do more harm than good. To ensure that fungicide applications have the intended consequence of curbing amphibian declines, researchers must identify which fungicides do not compromise the pathogen resistance mechanisms of amphibians.
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Affiliation(s)
- Jason R. Rohr
- University of South Florida, Department of Integrative Biology, Tampa, FL 33620, USA
| | - Jenise Brown
- University of South Florida, Department of Integrative Biology, Tampa, FL 33620, USA
- SWCA Environmental Consultants, Pittsburgh, PA, 15017, USA
| | | | | | - Rick A. Relyea
- Department of Biological Sciences, Rensselaer Polytechnic Inst., Troy, NY 12180, USA
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Knutie SA, Gabor CR, Kohl KD, Rohr JR. Do host-associated gut microbiota mediate the effect of an herbicide on disease risk in frogs? J Anim Ecol 2017; 87:489-499. [PMID: 29030867 DOI: 10.1111/1365-2656.12769] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 09/21/2017] [Indexed: 12/21/2022]
Abstract
Environmental stressors, such as pollutants, can increase disease risk in wildlife. For example, the herbicide atrazine affects host defences (e.g. resistance and tolerance) of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), but the mechanisms for these associations are not entirely clear. Given that pollutants can alter the gut microbiota of hosts, which in turn can affect their health and immune systems, one potential mechanism by which pollutants could increase infection risk is by influencing host-associated microbiota. Here, we test whether early-life exposure to the estimated environmental concentration (EEC; 200 μg/L) of atrazine affects the gut bacterial composition of Cuban tree frog (Osteopilus septentrionalis) tadpoles and adults and whether any atrazine-induced change in community composition might affect host defences against Bd. We also determine whether early-life changes in the stress hormone corticosterone affect gut microbiota by experimentally inhibiting corticosterone synthesis with metyrapone. With the exception of changing the relative abundances of two bacterial genera in adulthood, atrazine did not affect gut bacterial diversity or community composition of tadpoles (in vivo or in vitro) or adults. Metyrapone did not significantly affect bacterial diversity of tadpoles, but significantly increased bacterial diversity of adults. Gut bacterial diversity during Bd exposure did not predict host tolerance or resistance to Bd intensity in tadpoles or adults. However, early-life bacterial diversity negatively predicted Bd intensity as adult frogs. Specifically, Bd intensity as adults was associated negatively with the relative abundance of phylum Fusobacteria in the guts of tadpoles. Our results suggest that the effect of atrazine on Bd infection risk is not mediated by host-associated microbiota because atrazine does not affect microbiota of tadpoles or adults. However, host-associated microbes seem important in host resistance to Bd because the early-life microbiota, during immune system development, predicted later-life infection risk with Bd. Overall, our study suggests that increasing gut bacterial diversity and relative abundances of Fusobacteria might have lasting positive effects on amphibian health.
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Affiliation(s)
- Sarah A Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | - Caitlin R Gabor
- Department of Biology, Texas State University, San Marcos, TX, USA
| | - Kevin D Kohl
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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Knutie SA, Shea LA, Kupselaitis M, Wilkinson CL, Kohl KD, Rohr JR. Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs. Integr Comp Biol 2017; 57:732-742. [PMID: 28662573 PMCID: PMC5886343 DOI: 10.1093/icb/icx028] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against parasitic gut worms of frogs, but these effects depend on the stage of the host and infection, respectively.
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Affiliation(s)
- Sarah A. Knutie
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Lauren A. Shea
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Marinna Kupselaitis
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | | | - Kevin D. Kohl
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jason R. Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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Jayawardena UA, Rohr JR, Amerasinghe PH, Navaratne AN, Rajakaruna RS. Effects of agrochemicals on disease severity of Acanthostomum burminis infections (Digenea: Trematoda) in the Asian common toad, Duttaphrynus melanostictus. BMC ZOOL 2017. [DOI: 10.1186/s40850-017-0022-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Rodeo™ Herbicide Negatively Affects Blanchard's Cricket Frogs (Acris blanchardi) Survival and Alters the Skin-Associated Bacterial Community. J HERPETOL 2017. [DOI: 10.1670/16-092] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Early-life disruption of amphibian microbiota decreases later-life resistance to parasites. Nat Commun 2017; 8:86. [PMID: 28729558 PMCID: PMC5519754 DOI: 10.1038/s41467-017-00119-0] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 06/02/2017] [Indexed: 02/08/2023] Open
Abstract
Changes in the early-life microbiota of hosts might affect infectious disease risk throughout life, if such disruptions during formative times alter immune system development. Here, we test whether an early-life disruption of host-associated microbiota affects later-life resistance to infections by manipulating the microbiota of tadpoles and challenging them with parasitic gut worms as adults. We find that tadpole bacterial diversity is negatively correlated with parasite establishment in adult frogs: adult frogs that had reduced bacterial diversity as tadpoles have three times more worms than adults without their microbiota manipulated as tadpoles. In contrast, adult bacterial diversity during parasite exposure is not correlated with parasite establishment in adult frogs. Thus, in this experimental setup, an early-life disruption of the microbiota has lasting reductions on host resistance to infections, which is possibly mediated by its effects on immune system development. Our results support the idea that preventing early-life disruption of host-associated microbiota might confer protection against diseases later in life. Early-life microbiota alterations can affect infection susceptibility later in life, in animal models. Here, Knutie et al. show that manipulating the microbiota of tadpoles leads to increased susceptibility to parasitic infection in adult frogs, in the absence of substantial changes in the adults’ microbiota.
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Exposure to the Herbicide Atrazine Nonlinearly Affects Tadpole Corticosterone Levels. J HERPETOL 2017. [DOI: 10.1670/16-126] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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McMahon TA, Rohr JR, Bernal XE. Light and noise pollution interact to disrupt interspecific interactions. Ecology 2017; 98:1290-1299. [PMID: 28170099 DOI: 10.1002/ecy.1770] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/22/2016] [Accepted: 01/19/2017] [Indexed: 12/27/2022]
Abstract
Studies on the consequences of urbanization often examine the effects of light, noise, and heat pollution independently on isolated species providing a limited understanding of how these combined stressors affect species interactions. Here, we investigate how these factors interact to affect parasitic frog-biting midges (Corethrella spp.) and their túngara frog (Engystomops pustulosus) hosts. A survey of túngara frog calling sites revealed that frog abundance was not significantly correlated with urbanization, light, noise, or temperature. In contrast, frog-biting midges were sensitive to light pollution and noise pollution. Increased light intensity significantly reduced midge abundance at low noise levels. At high noise intensity, there were no midges regardless of light level. Two field experiments controlling light and noise levels to examine attraction of the midges to their host and their feeding behavior confirmed the causality of these field patterns. These findings demonstrate that both light and noise pollution disrupt this host-parasite interaction and highlight the importance of considering interactions among species and types of pollutants to accurately assess the impacts of urbanization on ecological communities.
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Affiliation(s)
- Taegan A McMahon
- Department of Biology, University of Tampa, 401 W. Kennedy Avenue, Tampa, Florida, 33606, USA
| | - Jason R Rohr
- Integrative Biology Department, University of South Florida, SCA 110, 4202 East Fowler Avenue, Tampa, Florida, 33620, USA
| | - Ximena E Bernal
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panamá City, Panamá.,Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana, 47907, USA
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Romansic JM, Johnson JE, Wagner RS, Hill RH, Gaulke CA, Vredenburg VT, Blaustein AR. Complex interactive effects of water mold, herbicide, and the fungus Batrachochytrium dendrobatidis on Pacific treefrog Hyliola regilla hosts. DISEASES OF AQUATIC ORGANISMS 2017; 123:227-238. [PMID: 28322209 DOI: 10.3354/dao03094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Infectious diseases pose a serious threat to global biodiversity. However, their ecological impacts are not independent of environmental conditions. For example, the pathogenic fungus Batrachochytrium dendrobatidis (Bd), which has contributed to population declines and extinctions in many amphibian species, interacts with several environmental factors to influence its hosts, but potential interactions with other pathogens and environmental contaminants are understudied. We examined the combined effects of Bd, a water mold (Achlya sp.), and the herbicide Roundup® Regular (hereafter, Roundup®) on larval Pacific treefrog Hyliola regilla hosts. We employed a 2 wk, fully factorial laboratory experiment with 3 ecologically realistic levels (0, 1, and 2 mg l-1 of active ingredient) of field-formulated Roundup®, 2 Achlya treatments (present and absent), and 2 Bd treatments (present and absent). Our results were consistent with sublethal interactive effects involving all 3 experimental factors. When Roundup® was absent, the proportion of Bd-exposed larvae infected with Bd was elevated in the presence of Achlya, consistent with Achlya acting as a synergistic cofactor that facilitated the establishment of Bd infection. However, this Achlya effect became nonsignificant at 1 mg l-1 of the active ingredient of Roundup® and disappeared at the highest Roundup® concentration. In addition, Roundup® decreased Bd loads among Bd-exposed larvae. Our study suggests complex interactive effects of a water mold and a contaminant on Bd infection in amphibian hosts. Achlya and Roundup® were both correlated with altered patterns of Bd infection, but in different ways, and Roundup® appeared to remove the influence of Achlya on Bd.
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Affiliation(s)
- John M Romansic
- Department of Integrative Biology, 3029 Cordley Hall, Oregon State University, Corvallis, Oregon 97331, USA
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Pochini KM, Hoverman JT. Reciprocal effects of pesticides and pathogens on amphibian hosts: The importance of exposure order and timing. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 221:359-366. [PMID: 27939635 DOI: 10.1016/j.envpol.2016.11.086] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/21/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
Ecological communities are increasingly exposed to natural and anthropogenic stressors. While the effects of individual stressors have been broadly investigated, there is growing evidence that multiple stressors are frequently encountered underscoring the need to examine interactive effects. Pesticides and infectious diseases are two common stressors that regularly occur together in nature. Given the documented lethal and sublethal effects of each stressor on individuals, there is the potential for interactive effects that alter disease outcomes and pesticide toxicity. Using larval wood frogs (Lithobates sylvaticus), we examined the reciprocal interaction between insecticides (carbaryl and thiamethoxam) and the viral pathogen ranavirus by testing whether: (1) prior ranavirus infection influences pesticide toxicity and (2) sublethal pesticide exposure increases susceptibility to and transmission of ranavirus. We found that prior infection with ranavirus increased pesticide toxicity; median lethal concentration (LC50) estimates were reduced by 72 and 55% for carbaryl and thiamethoxam, respectively. Importantly, LC50 estimates were reduced to concentrations found in natural systems. This is the first demonstration that an infection can alter pesticide toxicity. We also found that prior pesticide exposure exacerbated disease-induced mortality by increasing mortality rates, but effects on infection prevalence and transmission of the pathogen were minimal. Collectively, our results underscore the importance of incorporating complexity (i.e. order and timing of exposures) into research examining the interactions between natural and anthropogenic stressors. Given the environmental heterogeneity present in nature, such research will provide a more comprehensive understanding of how stressors affect wildlife.
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Affiliation(s)
- Katherine M Pochini
- Department of Forestry and Natural Resources, Purdue University, 715 West State St., West Lafayette, IN 47907-2061, United States.
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, 715 West State St., West Lafayette, IN 47907-2061, United States
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Immediate and lag effects of pesticide exposure on parasite resistance in larval amphibians. Parasitology 2017; 144:817-822. [DOI: 10.1017/s0031182016002560] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SUMMARYAcross host–parasite systems, there is evidence that pesticide exposure increases parasite loads and mortality following infection. However, whether these effects are driven by reductions in host resistance to infection or slower rates of parasite clearance is often unclear. Using controlled laboratory experiments, we examined the ability of larval northern leopard frogs (Lithobates pipiens) and American toads (Anaxyrus americanus) to resist and clear trematode (Echinoparyphium sp.) infections following exposure to the insecticide carbaryl. Northern leopard frogs exposed to 1 mg L−1 of carbaryl had 61% higher parasite loads compared with unexposed individuals, while there was no immediate effect of carbaryl on parasite encystment in American toads. However, when tadpoles were exposed to carbaryl and moved to freshwater for 14 days before the parasite challenge, we recovered 37 and 63% more parasites from carbaryl-exposed northern leopard frogs and American toads, respectively, compared with the control. No effects on clearance were found for either species. Collectively, our results suggest that pesticide exposure can reduce the ability of amphibians to resist parasite infections and that these effects can persist weeks following exposure. It is critical for researchers to incorporate species interactions into toxicity studies to improve our understanding of how contaminants affect ecological communities.
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Jones DK, Dang TD, Urbina J, Bendis RJ, Buck JC, Cothran RD, Blaustein AR, Relyea RA. Effect of Simultaneous Amphibian Exposure to Pesticides and an Emerging Fungal Pathogen, Batrachochytrium dendrobatidis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:671-679. [PMID: 28001054 DOI: 10.1021/acs.est.6b06055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Amphibian declines have been linked to numerous factors, including pesticide use and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Moreover, research has suggested a link between amphibian sensitivity to Bd and pesticide exposure. We simultaneously exposed postmetamorphic American toads (Anaxyrus americanus), western toads (A. boreas), spring peepers (Pseudacris crucifer), Pacific treefrogs (P. regilla), leopard frogs (Lithobates pipiens), and Cascades frogs (Rana cascadae) to a factorial combination of two pathogen treatments (Bd+, Bd-) and four pesticide treatments (control, ethanol vehicle, herbicide mixture, and insecticide mixture) for 14 d to quantify survival and infection load. We found no interactive effects of pesticides and Bd on anuran survival and no effects of pesticides on infection load. Mortality following Bd exposure increased in spring peepers and American toads and was dependent upon snout-vent length in western toads, American toads, and Pacific treefrogs. Previous studies reported effects of early sublethal pesticide exposure on amphibian Bd sensitivity and infection load at later life stages, but we found simultaneous exposure to sublethal pesticide concentrations and Bd had no such effect on postmetamorphic juvenile anurans. Future research investigating complex interactions between pesticides and Bd should employ a variety of pesticide formulations and Bd strains and follow the effects of exposure throughout ontogeny.
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Affiliation(s)
- Devin K Jones
- Department of Biological Sciences, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | | | | | - Randall J Bendis
- Department of Biological Sciences, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Julia C Buck
- Marine Science Institute, University of California Santa Barbara , Santa Barbara, California 93106, United States
| | - Rickey D Cothran
- Department of Biological Sciences, Southwestern Oklahoma State University , Weatherford, Oklahoma 73096, United States
| | | | - Rick A Relyea
- Department of Biological Sciences, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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50
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Dinh KV, Janssens L, Therry L, Bervoets L, Bonte D, Stoks R. Delayed effects of chlorpyrifos across metamorphosis on dispersal-related traits in a poleward moving damselfly. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 218:634-643. [PMID: 27476426 DOI: 10.1016/j.envpol.2016.07.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 06/13/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
How exposure to contaminants may interfere with the widespread poleward range expansions under global warming is largely unknown. Pesticide exposure may negatively affect traits shaping the speed of range expansion, including traits related to population growth rate and dispersal-related traits. Moreover, rapid evolution of growth rates during poleward range expansions may come at a cost of a reduced investment in detoxification and repair thereby increasing the vulnerability to contaminants at expanding range fronts. We tested effects of a sublethal concentration of the widespread pesticide chlorpyrifos on traits related to range expansion in replicated edge and core populations of the poleward moving damselfly Coenagrion scitulum reared at low and high food levels in a common garden experiment. Food limitation in the larval stage had strong negative effects both in the larval stage and across metamorphosis in the adult stage. Exposure to chlorpyrifos during the larval stage did not affect larval traits but caused delayed effects across metamorphosis by increasing the incidence of wing malformations during metamorphosis and by reducing a key component of the adult immune response. There was some support for an evolutionary trade-off scenario as the faster growing edge larvae suffered a higher mortality during metamorphosis. Instead, there was no clear support for the faster growing edge larvae being more vulnerable to chlorpyrifos. Our data indicate that sublethal delayed effects of pesticide exposure, partly in association with the rapid evolution of faster growth rates, may slow down range expansions.
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Affiliation(s)
- Khuong Van Dinh
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven, Leuven, Belgium.
| | - Lizanne Janssens
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven, Leuven, Belgium.
| | - Lieven Therry
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven, Leuven, Belgium; Centre National de la Recherche Scientifique (CNRS), Station d'Ecologie Expérimentale du CNRS à Moulis, USR 2936, F-09200, Moulis, France.
| | - Lieven Bervoets
- Systemic, Physiological and Ecotoxicological Research Group, University of Antwerp, Antwerp, Belgium.
| | - Dries Bonte
- Terrestrial Ecology Unit, Department of Biology, Faculty of Sciences, Ghent University, Ghent, Belgium.
| | - Robby Stoks
- Laboratory of Aquatic Ecology, Evolution and Conservation, University of Leuven, Leuven, Belgium.
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