49 results on '"Gratwicke B"'
Search Results
2. Introduced bullfrogs are associated with increased Batrachochytrium dendrobatidis prevalence and reduced occurrence of Korean treefrogs (vol 12, e0177860, 2017)
- Author
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Gratwicke, B, Borzee, A, Kosch, TA, Kim, M, Jang, Y, Gratwicke, B, Borzee, A, Kosch, TA, Kim, M, and Jang, Y
- Abstract
[This corrects the article DOI: 10.1371/journal.pone.0177860.].
- Published
- 2017
3. Factors affecting fish distribution in coastal habitats of the British Virgin Islands
- Author
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Gratwicke, B and Speight, M
- Subjects
Ecology (zoology) ,Life Sciences ,Biodiversity ,Environment ,Biology ,Zoological sciences - Abstract
Few studies of tropical fish communities compare fish distributions across the full range of near-shore tropical marine habitats. As a result, our understanding of tropical marine fish communities is often biased towards habitats preferred by researchers.The distribution and habitat preferences of all 136 fish species occurring at 106 stations in three bays off Tortola in the British Virgin Islands were assessed. At a species level, habitat type was often the key factor influencing fish distribution. Of the 44 species occurring at more than 10 stations, 3 were sand specialists, 5 were strongly associated with mangroves, 7 were dependent on seagrass and algal beds and 14 were found only on the forereef. Eleven species were widely distributed both on the forereef and in bays, and 9 of them showed clear evidence of ontogenetic partitioning. The juveniles all preferred bay habitat types and moved onto the forereef as they approached sexual maturity.At a community level, five distinct fish assemblages were found. The assemblage types were classified according to their distribution: 1) forereef, 2) reef flat, 3) non-mangrove associated seagrass, 4) mangrove associated seagrass and 5) eutrophic areas. Forereef stations were the most species-rich with 24 species per station while eutrophic stations had the most depauperate communities with only 4 species per station.Variation in fish species richness at each station was largely explained by a simple habitat complexity index. It accounted for 70% of the variation in fish species richness and 21% of the variation in fish abundance. Rugosity and variety of growth forms were the most important predictors of species richness, but the height of the habitat architecture was the most useful predictor of fish abundance. Artificial reefs were constructed to test the effects of each habitat complexity variable experimentally. Increasing rugosity, variety of growth forms and percentage hard substrate increased the observed number of species but increasing the variety of hole-sizes, and height had no effect. The only complexity variable that had a significant effect on fish abundance was percentage hard substrate. In addition to the static substrate structure, long-spined sea urchins Diadema antillarum affected fish distribution because small fish shelter from predators in their spines. The urchins increase species richness and abundance in low complexity seagrass beds, but on artificial reefs, where shelter was not a limiting factor, the effect was less pronounced.Organic pollution is another factor that negatively affects the fish community by reducing fish species richness and abundance. Poor water quality often alters the natural habitat, confounding observations, but fish species richness was reduced in polluted areas even when artificial reefs were used as habitat controls.The applications of these findings to the management and conservation of fish in the British Virgin Islands are discussed.
- Published
- 2016
4. Evaluating the probability of avoiding disease-related extinctions of Panamanian amphibians through captive breeding programs
- Author
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Gratwicke, B, Ross, H, Batista, Abel, Chaves, G., Crawford, A.J., Elizondro, L., Estrada, A., Evans, M., Garelle, D., Guerrel, J., Hertz, A., Hughey, M., Jaramillo, C.A., Kocke, B., Mandica, M., Medina, D., Richards-Zawacki, C.L., Ryan, M.J., Sosa-Bartuano, A., Voyles, J., Walker, B., Woodhams, D.C., and Ibáñez, R.
- Subjects
chytridiomycosis ,disease ,Panama ,extinction probability ,captive breeding ,amphibian ,ex situ conservation ,expert survey - Abstract
Amphibians around the world are declining from threats that cannot currently be mitigated, making it impossible to safeguard some species in their natural habitats. Amphibians in the mountainous neotropics are one example where severe diseaserelated declines prompted calls for the establishment of captive assurance colonies to avoid extinctions. We surveyed experts in Panamanian amphibians to determine the probability of avoiding chytridiomycosis-related extinctions using captive breeding programs. We ranked Panamanian amphibian species by perceived susceptibility to chytridiomycosis, then calculated the likelihood of avoiding extinction as the product of three probabilities, which include (1) finding sufficient founder animals, (2) successfully breeding these species in captivity and (3) becoming extinct in the wild. The likelihood of finding enough animals to create a captive founding population was low for many rare species, especially for salamanders and caecilians. It was also low for frogs which were once regularly encountered, but have already disappeared including Atelopus chiriquiensis, Craugastor emcelae, C. obesus, C. punctariolus, C. rhyacobatrachus, Ecnomiohyla rabborum, Isthmohyla calypsa and Oophaga speciosa. Our results indicate that captive breeding could improve the odds of avoiding extinction for species that have severely declined or are likely to decline due to chytridiomycosis including Atelopus certus, A. glyphus, A. limosus, A. varius, A. zeteki, Anotheca spinosa, Gastrotheca cornuta, Agalychnis lemur and Hemiphractus fasciatus. Priority species that experts predicted were highly susceptible to chytridiomycosis that might also benefit from ex situ management include Craugastor tabasarae, C. azueroensis, C. evanesco, Strabomantis bufoniformis and Colostethus panamansis. In spite of high levels of uncertainty, this expert assessment approach allowed us to refine our priorities for captive amphibian programs in Panama and identify priority conservation actions with a clearer understanding of the probability of success. Amphibians around the world are declining from threats that cannot currently be mitigated, making it impossible to safeguard some species in their natural habitats. Amphibians in the mountainous neotropics are one example where severe diseaserelated declines prompted calls for the establishment of captive assurance colonies to avoid extinctions. We surveyed experts in Panamanian amphibians to determine the probability of avoiding chytridiomycosis-related extinctions using captive breeding programs. We ranked Panamanian amphibian species by perceived susceptibility to chytridiomycosis, then calculated the likelihood of avoiding extinction as the product of three probabilities, which include (1) finding sufficient founder animals, (2) successfully breeding these species in captivity and (3) becoming extinct in the wild. The likelihood of finding enough animals to create a captive founding population was low for many rare species, especially for salamanders and caecilians. It was also low for frogs which were once regularly encountered, but have already disappeared including Atelopus chiriquiensis, Craugastor emcelae, C. obesus, C. punctariolus, C. rhyacobatrachus, Ecnomiohyla rabborum, Isthmohyla calypsa and Oophaga speciosa. Our results indicate that captive breeding could improve the odds of avoiding extinction for species that have severely declined or are likely to decline due to chytridiomycosis including Atelopus certus, A. glyphus, A. limosus, A. varius, A. zeteki, Anotheca spinosa, Gastrotheca cornuta, Agalychnis lemur and Hemiphractus fasciatus. Priority species that experts predicted were highly susceptible to chytridiomycosis that might also benefit from ex situ management include Craugastor tabasarae, C. azueroensis, C. evanesco, Strabomantis bufoniformis and Colostethus panamansis. In spite of high levels of uncertainty, this expert assessment approach allowed us to refine our priorities for captive amphibian programs in Panama and identify priority conservation actions with a clearer understanding of the probability of success.
- Published
- 2015
5. Evaluating the probability of avoiding disease‐related extinctions of Panamanian amphibians through captive breeding programs
- Author
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Gratwicke, B., primary, Ross, H., additional, Batista, A., additional, Chaves, G., additional, Crawford, A. J., additional, Elizondo, L., additional, Estrada, A., additional, Evans, M., additional, Garelle, D., additional, Guerrel, J., additional, Hertz, A., additional, Hughey, M., additional, Jaramillo, C. A., additional, Klocke, B., additional, Mandica, M., additional, Medina, D., additional, Richards‐Zawacki, C. L., additional, Ryan, M. J., additional, Sosa‐Bartuano, A., additional, Voyles, J., additional, Walker, B., additional, Woodhams, D. C., additional, and Ibáñez, R., additional
- Published
- 2016
- Full Text
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6. Variation in Thermal Performance of a Widespread Pathogen, the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis
- Author
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Gratwicke, B, Stevenson, LA, Alford, RA, Bell, SC, Roznik, EA, Berger, L, Pike, DA, Gratwicke, B, Stevenson, LA, Alford, RA, Bell, SC, Roznik, EA, Berger, L, and Pike, DA
- Abstract
Rates of growth and reproduction of the pathogens that cause emerging infectious diseases can be affected by local environmental conditions; these conditions can thus influence the strength and nature of disease outbreaks. An understanding of these relationships is important for understanding disease ecology and developing mitigation strategies. Widespread emergence of the fungal disease chytridiomycosis has had devastating effects on amphibian populations. The causative pathogen, Batrachochytriumdendrobatidis (Bd), is sensitive to temperature, but its thermal tolerances are not well studied. We examined the thermal responses of three Bd isolates collected across a latitudinal gradient in eastern Australia. Temperature affected all aspects of Bd growth and reproduction that we measured, in ways that often differed among Bd isolates. Aspects of growth, reproduction, and their relationships to temperature that differed among isolates included upper thermal maxima for growth (26, 27, or 28 °C, depending on the isolate), relationships between zoospore production and temperature, and zoospore activity and temperature. Two isolates decreased zoospore production as temperature increased, whereas the third isolate was less fecund overall, but did not show a strong response to temperature until reaching the upper limit of its thermal tolerance. Our results show differentiation in life-history traits among isolates within Australia, suggesting that the pathogen may exhibit local adaptation. An understanding of how environmental temperatures can limit pathogens by constraining fitness will enhance our ability to assess pathogen dynamics in the field, model pathogen spread, and conduct realistic experiments on host susceptibility and disease transmission.
- Published
- 2013
7. Prior Infection Does Not Improve Survival against the Amphibian Disease Chytridiomycosis
- Author
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Gratwicke, B, Cashins, SD, Grogan, LF, McFadden, M, Hunter, D, Harlow, PS, Berger, L, Skerratt, LF, Gratwicke, B, Cashins, SD, Grogan, LF, McFadden, M, Hunter, D, Harlow, PS, Berger, L, and Skerratt, LF
- Abstract
Many amphibians have declined globally due to introduction of the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Hundreds of species, many in well-protected habitats, remain as small populations at risk of extinction. Currently the only proven conservation strategy is to maintain species in captivity to be reintroduced at a later date. However, methods to abate the disease in the wild are urgently needed so that reintroduced and wild animals can survive in the presence of Bd. Vaccination has been widely suggested as a potential strategy to improve survival. We used captive-bred offspring of critically endangered booroolong frogs (Litoria booroolongensis) to test if vaccination in the form of prior infection improves survival following re exposure. We infected frogs with a local Bd isolate, cleared infection after 30 days (d) using itraconazole just prior to the onset of clinical signs, and then re-exposed animals to Bd at 110 d. We found prior exposure had no effect on survival or infection intensities, clearly showing that real infections do not stimulate a protective adaptive immune response in this species. This result supports recent studies suggesting Bd may evade or suppress host immune functions. Our results suggest vaccination is unlikely to be useful in mitigating chytridiomycosis. However, survival of some individuals from all experimental groups indicates existence of protective innate immunity. Understanding and promoting this innate resistance holds potential for enabling species recovery.
- Published
- 2013
8. Population Status of a Cryptic Top Predator: An Island-Wide Assessment of Tigers in Sumatran Rainforests
- Author
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Gratwicke, B, Wibisono, HT, Linkie, M, Guillera-Arroita, G, Smith, JA, Sunarto, Pusparini, W, Asriadi, Baroto, P, Brickle, N, Dinata, Y, Gemita, E, Gunaryadi, D, Haidir, IA, Herwansyah, Karina, I, Kiswayadi, D, Kristiantono, D, Kurniawan, H, Lahoz-Monfort, JJ, Leader-Williams, N, Maddox, T, Martyr, DJ, Maryati, Nugroho, A, Parakkasi, K, Priatna, D, Ramadiyanta, E, Ramono, WS, Reddy, GV, Rood, EJJ, Saputra, DY, Sarimudi, A, Salampessy, A, Septayuda, E, Suhartono, T, Sumantri, A, Susilo, Tanjung, I, Tarmizi, Yulianto, K, Yunus, M, Zulfahmi, Gratwicke, B, Wibisono, HT, Linkie, M, Guillera-Arroita, G, Smith, JA, Sunarto, Pusparini, W, Asriadi, Baroto, P, Brickle, N, Dinata, Y, Gemita, E, Gunaryadi, D, Haidir, IA, Herwansyah, Karina, I, Kiswayadi, D, Kristiantono, D, Kurniawan, H, Lahoz-Monfort, JJ, Leader-Williams, N, Maddox, T, Martyr, DJ, Maryati, Nugroho, A, Parakkasi, K, Priatna, D, Ramadiyanta, E, Ramono, WS, Reddy, GV, Rood, EJJ, Saputra, DY, Sarimudi, A, Salampessy, A, Septayuda, E, Suhartono, T, Sumantri, A, Susilo, Tanjung, I, Tarmizi, Yulianto, K, Yunus, M, and Zulfahmi
- Abstract
Large carnivores living in tropical rainforests are under immense pressure from the rapid conversion of their habitat. In response, millions of dollars are spent on conserving these species. However, the cost-effectiveness of such investments is poorly understood and this is largely because the requisite population estimates are difficult to achieve at appropriate spatial scales for these secretive species. Here, we apply a robust detection/non-detection sampling technique to produce the first reliable population metric (occupancy) for a critically endangered large carnivore; the Sumatran tiger (Panthera tigris sumatrae). From 2007-2009, seven landscapes were surveyed through 13,511 km of transects in 394 grid cells (17×17 km). Tiger sign was detected in 206 cells, producing a naive estimate of 0.52. However, after controlling for an unequal detection probability (where p = 0.13±0.017; ±S.E.), the estimated tiger occupancy was 0.72±0.048. Whilst the Sumatra-wide survey results gives cause for optimism, a significant negative correlation between occupancy and recent deforestation was found. For example, the Northern Riau landscape had an average deforestation rate of 9.8%/yr and by far the lowest occupancy (0.33±0.055). Our results highlight the key tiger areas in need of protection and have led to one area (Leuser-Ulu Masen) being upgraded as a 'global priority' for wild tiger conservation. However, Sumatra has one of the highest global deforestation rates and the two largest tiger landscapes identified in this study will become highly fragmented if their respective proposed roads networks are approved. Thus, it is vital that the Indonesian government tackles these threats, e.g. through improved land-use planning, if it is to succeed in meeting its ambitious National Tiger Recovery Plan targets of doubling the number of Sumatran tigers by 2022.
- Published
- 2011
9. Impact of Iron Duke Pyrite Mine on water chemistry and aquatic life – Mazowe Valley, Zimbabwe
- Author
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Ravengai, S, primary, Love, D, additional, Love, I, additional, Gratwicke, B, additional, Mandingaisa, O, additional, and Owen, RJS, additional
- Published
- 2007
- Full Text
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10. The relationship between fish species richness, abundance and habitat complexity in a range of shallow tropical marine habitats
- Author
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Gratwicke, B., primary and Speight, M. R., additional
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- 2005
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11. Effects of habitat complexity on Caribbean marine fish assemblages
- Author
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Gratwicke, B, primary and Speight, MR, additional
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- 2005
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12. The distribution and relative abundance of stream fishes in the upper Manyame River, Zimbabwe, in relation to land use, pollution and exotic predators
- Author
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Gratwicke, B, primary, Marshall, B E, additional, and Nhiwatiwa, T, additional
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- 2003
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13. The impact of Azolla filiculoides Lam. on animal biodiversity in streams in Zimbabwe
- Author
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Gratwicke, B., primary and Marshall, B. E., additional
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- 2001
- Full Text
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14. The relationship between the exotic predators Micropterus salmoides and Serranochromis robustus and native stream fishes in Zimbabwe
- Author
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Gratwicke, B., primary and Marshall, B. E., additional
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- 2001
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15. THE BARRED MINNOWS (TELEOSTEI: CYPRINIDAE) OF ZIMBABWE: IS THERE CAUSE FOR CONCERN?
- Author
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Marshall, B. E., primary and Gratwicke, B., additional
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- 1998
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16. THE EFFECT OF SEASON ON A BIOTIC WATER QUALITY INDEX: A CASE STUDY OF THE YELLOW JACKET AND MAZOWE RIVERS, ZIMBABWE.
- Author
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Gratwicke, B., primary
- Published
- 1998
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17. Range-wide salamander densities reveal a key component of terrestrial vertebrate biomass in eastern North American forests.
- Author
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Grant EHC, Fleming J, Bastiaans E, Brand AB, Brooks JL, Devlin C, Epp K, Evans M, Fisher-Reid MC, Gratwicke B, Grayson KL, Haydt NT, Hernández-Pacheco R, Hocking DJ, Hyde A, Losito M, MacKnight MG, Matlaga TJH, Mead L, Muñoz D, Peterman W, Puza V, Shafer C, Sterrett SC, Sutherland C, Thompson LM, Warwick AR, Wright AD, Yurewicz K, and Miller DAW
- Subjects
- Animals, Biodiversity, North America, Urodela physiology, Forests, Biomass, Population Density
- Abstract
Characterizing the population density of species is a central interest in ecology. Eastern North America is the global hotspot for biodiversity of plethodontid salamanders, an inconspicuous component of terrestrial vertebrate communities, and among the most widespread is the eastern red-backed salamander, Plethodon cinereus . Previous work suggests population densities are high with significant geographic variation, but comparisons among locations are challenged by lack of standardization of methods and failure to accommodate imperfect detection. We present results from a large-scale research network that accounts for detection uncertainty using systematic survey protocols and robust statistical models. We analysed mark-recapture data from 18 study areas across much of the species range. Estimated salamander densities ranged from 1950 to 34 300 salamanders ha
-1 , with a median of 9965 salamanders ha-1 . We compared these results to previous estimates for P. cinereus and other abundant terrestrial vertebrates. We demonstrate that overall the biomass of P. cinereus , a secondary consumer, is of similar or greater magnitude to widespread primary consumers such as white-tailed deer ( Odocoileus virginianus ) and Peromyscus mice, and two to three orders of magnitude greater than common secondary consumer species. Our results add empirical evidence that P. cinereus , and amphibians in general, are an outsized component of terrestrial vertebrate communities in temperate ecosystems.- Published
- 2024
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18. Mini saunas save endangered frogs from fungal disease.
- Author
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Gratwicke B and Savage A
- Subjects
- Animals, Anura microbiology, Mycoses microbiology, Mycoses veterinary, Mycoses drug therapy, Endangered Species
- Published
- 2024
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19. Sequence capture identifies fastidious chytrid fungi directly from host tissue.
- Author
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Mulder KP, Savage AE, Gratwicke B, Longcore JE, Bronikowski E, Evans M, Longo AV, Kurata NP, Walsh T, Pasmans F, McInerney N, Murray S, Martel A, and Fleischer RC
- Subjects
- Animals, Phylogeny, Amphibians genetics, Amphibians microbiology, Biological Evolution, DNA, Chytridiomycota genetics
- Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered in 1998 as the cause of chytridiomycosis, an emerging infectious disease causing mass declines in amphibian populations worldwide. The rapid population declines of the 1970s-1990s were likely caused by the spread of a highly virulent lineage belonging to the Bd-GPL clade that was introduced to naïve susceptible populations. Multiple genetically distinct and regional lineages of Bd have since been isolated and sequenced, greatly expanding the known biological diversity within this fungal pathogen. To date, most Bd research has been restricted to the limited number of samples that could be isolated using culturing techniques, potentially causing a selection bias for strains that can grow on media and missing other unculturable or fastidious strains that are also present on amphibians. We thus attempted to characterize potentially non-culturable genetic lineages of Bd from distinct amphibian taxa using sequence capture technology on DNA extracted from host tissue and swabs. We focused our efforts on host taxa from two different regions that likely harbored distinct Bd clades: (1) wild-caught leopard frogs (Rana) from North America, and (2) a Japanese Giant Salamander (Andrias japonicus) at the Smithsonian Institution's National Zoological Park that exhibited signs of disease and tested positive for Bd using qPCR, but multiple attempts failed to isolate and culture the strain for physiological and genetic characterization. We successfully enriched for and sequenced thousands of fungal genes from both host clades, and Bd load was positively associated with number of recovered Bd sequences. Phylogenetic reconstruction placed all the Rana-derived strains in the Bd-GPL clade. In contrast, the A. japonicus strain fell within the Bd-Asia3 clade, expanding the range of this clade and generating additional genomic data to confirm its placement. The retrieved ITS locus matched public barcoding data from wild A. japonicus and Bd infections found on other amphibians in India and China, suggesting that this uncultured clade is widespread across Asia. Our study underscores the importance of recognizing and characterizing the hidden diversity of fastidious strains in order to reconstruct the spatiotemporal and evolutionary history of Bd. The success of the sequence capture approach highlights the utility of directly sequencing pathogen DNA from host tissue to characterize cryptic diversity that is missed by culture-reliant approaches., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2024
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20. Phylosymbiosis shapes skin bacterial communities and pathogen-protective function in Appalachian salamanders.
- Author
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Osborne OG, Jiménez RR, Byrne AQ, Gratwicke B, Ellison A, and Muletz-Wolz CR
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- Animals, Bacteria classification, Bacteria genetics, Bacteria isolation & purification, Urodela microbiology, Microbiota, Skin microbiology, Symbiosis, Phylogeny, Batrachochytrium genetics
- Abstract
Phylosymbiosis is an association between host-associated microbiome composition and host phylogeny. This pattern can arise via the evolution of host traits, habitat preferences, diets, and the co-diversification of hosts and microbes. Understanding the drivers of phylosymbiosis is vital for modelling disease-microbiome interactions and manipulating microbiomes in multi-host systems. This study quantifies phylosymbiosis in Appalachian salamander skin in the context of infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd), while accounting for environmental microbiome exposure. We sampled ten salamander species representing >150M years of divergence, assessed their Bd infection status, and analysed their skin and environmental microbiomes. Our results reveal a significant signal of phylosymbiosis, whereas the local environmental pool of microbes, climate, geography, and Bd infection load had a smaller impact. Host-microbe co-speciation was not evident, indicating that the effect stems from the evolution of host traits influencing microbiome assembly. Bd infection is correlated with host phylogeny and the abundance of Bd-inhibitory bacterial strains, suggesting that the long-term evolutionary dynamics between salamander hosts and their skin microbiomes affect the present-day distribution of the pathogen, along with habitat-linked exposure risk. Five Bd-inhibitory bacterial strains showed unusual generalism: occurring in most host species and habitats. These generalist strains may enhance the likelihood of probiotic manipulations colonising and persisting on hosts. Our results underscore the substantial influence of host-microbiome eco-evolutionary dynamics on environmental health and disease outcomes., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)
- Published
- 2024
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21. Author Correction: Ongoing declines for the world's amphibians in the face of emerging threats.
- Author
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Luedtke JA, Chanson J, Neam K, Hobin L, Maciel AO, Catenazzi A, Borzée A, Hamidy A, Aowphol A, Jean A, Sosa-Bartuano Á, Fong G A, de Silva A, Fouquet A, Angulo A, Kidov AA, Muñoz Saravia A, Diesmos AC, Tominaga A, Shrestha B, Gratwicke B, Tjaturadi B, Martínez Rivera CC, Vásquez Almazán CR, Señaris C, Chandramouli SR, Strüssmann C, Cortez Fernández CF, Azat C, Hoskin CJ, Hilton-Taylor C, Whyte DL, Gower DJ, Olson DH, Cisneros-Heredia DF, Santana DJ, Nagombi E, Najafi-Majd E, Quah ESH, Bolaños F, Xie F, Brusquetti F, Álvarez FS, Andreone F, Glaw F, Castañeda FE, Kraus F, Parra-Olea G, Chaves G, Medina-Rangel GF, González-Durán G, Ortega-Andrade HM, Machado IF, Das I, Dias IR, Urbina-Cardona JN, Crnobrnja-Isailović J, Yang JH, Jianping J, Wangyal JT, Rowley JJL, Measey J, Vasudevan K, Chan KO, Gururaja KV, Ovaska K, Warr LC, Canseco-Márquez L, Toledo LF, Díaz LM, Khan MMH, Meegaskumbura M, Acevedo ME, Napoli MF, Ponce MA, Vaira M, Lampo M, Yánez-Muñoz MH, Scherz MD, Rödel MO, Matsui M, Fildor M, Kusrini MD, Ahmed MF, Rais M, Kouamé NG, García N, Gonwouo NL, Burrowes PA, Imbun PY, Wagner P, Kok PJR, Joglar RL, Auguste RJ, Brandão RA, Ibáñez R, von May R, Hedges SB, Biju SD, Ganesh SR, Wren S, Das S, Flechas SV, Ashpole SL, Robleto-Hernández SJ, Loader SP, Incháustegui SJ, Garg S, Phimmachak S, Richards SJ, Slimani T, Osborne-Naikatini T, Abreu-Jardim TPF, Condez TH, De Carvalho TR, Cutajar TP, Pierson TW, Nguyen TQ, Kaya U, Yuan Z, Long B, Langhammer P, and Stuart SN
- Published
- 2024
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22. Ongoing declines for the world's amphibians in the face of emerging threats.
- Author
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Luedtke JA, Chanson J, Neam K, Hobin L, Maciel AO, Catenazzi A, Borzée A, Hamidy A, Aowphol A, Jean A, Sosa-Bartuano Á, Fong G A, de Silva A, Fouquet A, Angulo A, Kidov AA, Muñoz Saravia A, Diesmos AC, Tominaga A, Shrestha B, Gratwicke B, Tjaturadi B, Martínez Rivera CC, Vásquez Almazán CR, Señaris C, Chandramouli SR, Strüssmann C, Cortez Fernández CF, Azat C, Hoskin CJ, Hilton-Taylor C, Whyte DL, Gower DJ, Olson DH, Cisneros-Heredia DF, Santana DJ, Nagombi E, Najafi-Majd E, Quah ESH, Bolaños F, Xie F, Brusquetti F, Álvarez FS, Andreone F, Glaw F, Castañeda FE, Kraus F, Parra-Olea G, Chaves G, Medina-Rangel GF, González-Durán G, Ortega-Andrade HM, Machado IF, Das I, Dias IR, Urbina-Cardona JN, Crnobrnja-Isailović J, Yang JH, Jianping J, Wangyal JT, Rowley JJL, Measey J, Vasudevan K, Chan KO, Gururaja KV, Ovaska K, Warr LC, Canseco-Márquez L, Toledo LF, Díaz LM, Khan MMH, Meegaskumbura M, Acevedo ME, Napoli MF, Ponce MA, Vaira M, Lampo M, Yánez-Muñoz MH, Scherz MD, Rödel MO, Matsui M, Fildor M, Kusrini MD, Ahmed MF, Rais M, Kouamé NG, García N, Gonwouo NL, Burrowes PA, Imbun PY, Wagner P, Kok PJR, Joglar RL, Auguste RJ, Brandão RA, Ibáñez R, von May R, Hedges SB, Biju SD, Ganesh SR, Wren S, Das S, Flechas SV, Ashpole SL, Robleto-Hernández SJ, Loader SP, Incháustegui SJ, Garg S, Phimmachak S, Richards SJ, Slimani T, Osborne-Naikatini T, Abreu-Jardim TPF, Condez TH, De Carvalho TR, Cutajar TP, Pierson TW, Nguyen TQ, Kaya U, Yuan Z, Long B, Langhammer P, and Stuart SN
- Subjects
- Animals, Biodiversity, Conservation of Natural Resources economics, Conservation of Natural Resources trends, Extinction, Biological, Risk, Urodela classification, Amphibians classification, Climate Change statistics & numerical data, Ecosystem, Endangered Species statistics & numerical data, Endangered Species trends
- Abstract
Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action
1,2 . Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4 . Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends., (© 2023. The Author(s).)- Published
- 2023
- Full Text
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23. Immune priming prior to pathogen exposure sheds light on the relationship between host, microbiome and pathogen in disease.
- Author
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Kaganer AW, Ossiboff RJ, Keith NI, Schuler KL, Comizzoli P, Hare MP, Fleischer RC, Gratwicke B, and Bunting EM
- Abstract
Dynamic interactions between host, pathogen and host-associated microbiome dictate infection outcomes. Pathogens including Batrachochytrium dendrobatidis (Bd) threaten global biodiversity, but conservation efforts are hindered by limited understanding of amphibian host, Bd and microbiome interactions. We conducted a vaccination and infection experiment using Eastern hellbender salamanders ( Cryptobranchus alleganiensis alleganiensis ) challenged with Bd to observe infection, skin microbial communities and gene expression of host skin, pathogen and microbiome throughout the experiment. Most animals survived high Bd loads regardless of their vaccination status and vaccination did not affect pathogen load, but host gene expression differed based on vaccination. Oral vaccination (exposure to killed Bd) stimulated immune gene upregulation while topically and sham-vaccinated animals did not significantly upregulate immune genes. In early infection, topically vaccinated animals upregulated immune genes but orally and sham-vaccinated animals downregulated immune genes. Bd increased pathogenicity-associated gene expression in late infection when Bd loads were highest. The microbiome was altered by Bd, but there was no correlation between anti-Bd microbe abundance or richness and pathogen burden. Our observations suggest that hellbenders initially generate a vigorous immune response to Bd, which is ineffective at controlling disease and is subsequently modulated. Interactions with antifungal skin microbiota did not influence disease progression., (© 2023 The Authors.)
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- 2023
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24. Body condition, skin bacterial communities and disease status: insights from the first release trial of the limosa harlequin frog, Atelopus limosus .
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Estrada A, Medina D, Gratwicke B, Ibáñez R, and Belden LK
- Subjects
- Animals, Anura genetics, Bacteria, Bufonidae genetics, Plant Breeding, RNA, Ribosomal, 16S genetics, Skin microbiology, Chytridiomycota genetics, Mycoses microbiology, Mycoses veterinary
- Abstract
Many endangered amphibian species survive in captive breeding facilities, but there have been few attempts to reintroduce captive-born individuals to rebuild wild populations. We conducted a soft-release trial of limosa harlequin frogs, Atelopus limosus, which are highly susceptible to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), to understand changes associated with the transition from captivity to the wild. Specifically, we assessed changes in body condition, skin-associated bacterial communities and disease status after release. Frogs were housed individually in field mesocosms and monitored for 27 days. Body condition did not significantly change in the mesocosms, and was similar to, or higher than, that of wild conspecifics at day 27. The skin bacteria of captive-born frogs, based on 16S rRNA gene amplicons, became similar to that of wild conspecifics after 27 days in mesocosms. Prevalence of Bd in wild conspecifics was 13-27%, and 15% of the A. limosus in mesocosms became infected with Bd, but no mortality of infected frogs was observed. We conclude that mesocosms are suitable for systematically and repeatedly monitoring amphibians during release trials, and that body condition, the skin microbiome, and Bd status can all change within one month of placement of captive-born individuals back into the wild.
- Published
- 2022
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25. Inhibitory Bacterial Diversity and Mucosome Function Differentiate Susceptibility of Appalachian Salamanders to Chytrid Fungal Infection.
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Jiménez RR, Carfagno A, Linhoff L, Gratwicke B, Woodhams DC, Chafran LS, Bletz MC, Bishop B, and Muletz-Wolz CR
- Subjects
- Animals, Bacteria genetics, RNA, Ribosomal, 16S genetics, Urodela microbiology, Chytridiomycota genetics, Mycoses microbiology, Mycoses veterinary
- Abstract
Mucosal defenses are crucial in animals for protection against pathogens and predators. Host defense peptides (antimicrobial peptides, AMPs) as well as skin-associated microbes are key components of mucosal immunity, particularly in amphibians. We integrate microbiology, molecular biology, network-thinking, and proteomics to understand how host and microbially derived products on amphibian skin (referred to as the mucosome) serve as pathogen defenses. We studied defense mechanisms against chytrid pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), in four salamander species with different Batrachochytrium susceptibilities. Bd infection was quantified using qPCR, mucosome function (i.e., ability to kill Bd or Bsal zoospores in vitro ), skin bacterial communities using 16S rRNA gene amplicon sequencing, and the role of Bd-inhibitory bacteria in microbial networks across all species. We explored the presence of candidate-AMPs in eastern newts and red-backed salamanders. Eastern newts had the highest Bd prevalence and mucosome function, while red-back salamanders had the lowest Bd prevalence and mucosome function, and two-lined salamanders and seal salamanders were intermediates. Salamanders with highest Bd infection intensity showed greater mucosome function. Bd infection prevalence significantly decreased as putative Bd-inhibitory bacterial richness and relative abundance increased on hosts. In co-occurrence networks, some putative Bd-inhibitory bacteria were found as hub-taxa, with red-backs having the highest proportion of protective hubs and positive associations related to putative Bd-inhibitory hub bacteria. We found more AMP candidates on salamanders with lower Bd susceptibility. These findings suggest that salamanders possess distinct innate mechanisms that affect chytrid fungi. IMPORTANCE How host mucosal defenses interact, and influence disease outcome is critical in understanding host defenses against pathogens. A more detailed understanding is needed of the interactions between the host and the functioning of its mucosal defenses in pathogen defense. This study investigates the variability of chytrid susceptibility in salamanders and the innate defenses each species possesses to mediate pathogens, thus advancing the knowledge toward a deeper understanding of the microbial ecology of skin-associated bacteria and contributing to the development of bioaugmentation strategies to mediate pathogen infection and disease. This study improves the understanding of complex immune defense mechanisms in salamanders and highlights the potential role of the mucosome to reduce the probability of Bd disease development and that putative protective bacteria may reduce likelihood of Bd infecting skin.
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- 2022
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26. Genetically modifying skin microbe to produce violacein and augmenting microbiome did not defend Panamanian golden frogs from disease.
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Becker MH, Brophy JAN, Barrett K, Bronikowski E, Evans M, Glassey E, Kaganer AW, Klocke B, Lassiter E, Meyer AJ, Muletz-Wolz CR, Fleischer RC, Voigt CA, and Gratwicke B
- Abstract
We designed two probiotic treatments to control chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) on infected Panamanian golden frogs (Atelopus zeteki), a species that is thought to be extinct in the wild due to Bd. The first approach disrupted the existing skin microbe community with antibiotics then exposed the frogs to a core golden frog skin microbe (Diaphorobacter sp.) that we genetically modified to produce high titers of violacein, a known antifungal compound. One day following probiotic treatment, the engineered Diaphorobacter and the violacein-producing pathway could be detected on the frogs but the treatment failed to improve frog survival when exposed to Bd. The second approach exposed frogs to the genetically modified bacterium mixed into a consortium with six other known anti-Bd bacteria isolated from captive A. zeteki, with no preliminary antibiotic treatment. The consortium treatment increased the frequency and abundance of three probiotic isolates (Janthinobacterium, Chryseobacterium, and Stenotrophomonas) and these persisted on the skin 4 weeks after probiotic treatment. There was a temporary increase in the frequency and abundance of three other probiotics isolates (Masillia, Serratia, and Pseudomonas) and the engineered Diaphorobacter isolate, but they subsequently disappeared from the skin. This treatment also failed to reduce frog mortality upon exposure., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)
- Published
- 2021
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27. Physiological impacts of temperature variability and climate warming in hellbenders ( Cryptobranchus alleganiensis ).
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Terrell KA, Quintero RP, Galicia VA, Bronikowski E, Evans M, Kleopfer JD, Murray S, Murphy JB, Nissen BD, and Gratwicke B
- Abstract
Cold-adapted hellbender salamanders that inhabit cool mountain streams are expected to fare poorly under warmer projected climate scenarios. This study investigated the physiological consequences of long-term, naturalistic temperature variation on juvenile hellbenders under simulated current and warmer (+1.6 C) climates vs. controlled steady temperatures. Mean temperature and temperature variability were both important predictors of growth as indicated by monthly body mass change (%), stress as indicated by neutrophil:lymphocyte (N:L) ratio and bacteria-killing ability of blood. Cold exposure in hellbenders was associated with weight loss, increased N:L ratios and reduced Escherichia coli killing ability of blood, and these effects were less pronounced under a warmer climate scenario. These observations suggest that cold periods may be more stressful for hellbenders than previously understood. Growth rates peaked in late spring and late fall around 14-17°C. Hellbenders experiencing warmer simulated climates retained body condition better in winter, but this was counter-balanced by a prolonged lack of growth in the 3-month summer period leading up to the fall breeding season where warmer simulated conditions resulted in an average loss of -0.6% body mass/month, compared to a gain +1.5% body mass/month under current climate scenario. Hellbenders can physiologically tolerate projected warmer temperatures and temperature fluctuations, but warmer summers may cause animals to enter the fall breeding season with a caloric deficit that may have population-level consequences., (© The Author(s) 2021. Published by Oxford University Press and the Society for Experimental Biology.)
- Published
- 2021
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28. Expanded host and geographic range of tadpole associations with the Severe Perkinsea Infection group.
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Smilansky V, Jirků M, Milner DS, Ibáñez R, Gratwicke B, Nicholls A, Lukeš J, Chambouvet A, and Richards TA
- Subjects
- Alaska, Animals, Florida, North America, Phylogeny, Larva
- Abstract
Severe Perkinsea infection is an emerging disease of amphibians, specifically tadpoles. Disease presentation correlates with liver infections of a subclade of Perkinsea (Alveolata) protists, named Pathogenic Perkinsea Clade (PPC). Tadpole mortality events associated with PPC infections have been reported across North America, from Alaska to Florida. Here, we investigate the geographic and host range of PPC associations in seemingly healthy tadpoles sampled from Panama, a biogeographic provenance critically affected by amphibian decline. To complement this work, we also investigate a mortality event among Hyla arborea tadpoles in captive-bred UK specimens. PPC SSU rDNA was detected in 10 of 81 Panama tadpoles tested, and H. arborea tadpoles from the UK. Phylogenies of the Perkinsea SSU rDNA sequences demonstrate they are highly similar to PPC sequences sampled from mortality events in the USA, and phylogenetic analysis of tadpole mitochondrial SSU rDNA demonstrates, for the first time, PPC associations in diverse hylids. These data provide further understanding of the biogeography and host range of this putative pathogenic group, factors likely to be important for conservation planning.
- Published
- 2021
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29. David E. Wildt-An Inspiring Leader in the Conservation of Wild Species.
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Pukazhenthi B, Songsasen N, Brown J, Comizzoli P, Crosier A, Hagedorn M, Gratwicke B, Pitt W, and Monfort S
- Subjects
- Animals, Endangered Species, History, 20th Century, History, 21st Century, Museums, Reproduction, Conservation of Natural Resources history
- Published
- 2020
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30. Sustained immune activation is associated with susceptibility to the amphibian chytrid fungus.
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Savage AE, Gratwicke B, Hope K, Bronikowski E, and Fleischer RC
- Subjects
- Animals, Anura genetics, Phylogeny, Ranidae, Chytridiomycota genetics, Mycoses genetics, Mycoses veterinary
- Abstract
The disease chytridiomycosis caused by the fungus Bd has devastated amphibian populations worldwide. Functional genomic contributions to host susceptibility remain enigmatic and vary between species and populations. We conducted experimental Bd infections in Rana yavapaiensis, a species with intraspecific variation in chytridiomycosis susceptibility, to assess the skin and spleen transcriptomic response to infection over time. We predicted that increased immune gene expression would be associated with a positive disease outcome, but we instead found that surviving frogs had significantly reduced immune gene expression compared to susceptible frogs and to uninfected controls. MHC class IIβ gene expression was also significantly higher in susceptible frogs compared to surviving frogs. Furthermore, susceptible frogs expressed a significantly larger number of distinct class IIβ alleles, demonstrating a negative correlation between class IIβ expression, functional diversity, and survival. Expression of the MHC class IIβ locus previously associated with Bd disease outcomes was a significant predictor of Bd infection intensity at early infection stages but not at late infection stages, suggesting initial MHC-linked immune processes are important for ultimate disease outcomes. We infer through disease association and phylogenetic analysis that certain MHC variants are linked to the immune expression that was negatively associated with survival, and we hypothesize that frogs that did not express these alleles could better survive infections. Our study finds that MHC expression at early and late infection stages predicts Bd infection intensity, and suggests that generating a sustained immune response against Bd may be counterproductive for surviving chytridiomycosis in this partially susceptible species., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2020
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31. Spindly leg syndrome in Atelopus varius is linked to environmental calcium and phosphate availability.
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Lassiter E, Garcés O, Higgins K, Baitchman E, Evans M, Guerrel J, Klaphake E, Snellgrove D, Ibáñez R, and Gratwicke B
- Subjects
- Animals, Bufonidae growth & development, Calcium administration & dosage, Environment, Musculoskeletal Abnormalities etiology, Phosphates administration & dosage, Syndrome, Bufonidae abnormalities, Calcium adverse effects, Musculoskeletal Abnormalities pathology, Phosphates adverse effects
- Abstract
Spindly leg syndrome (SLS) is a relatively common musculoskeletal abnormality associated with captive-rearing of amphibians with aquatic larvae. We conducted an experiment to investigate the role of environmental calcium and phosphate in causing SLS in tadpoles. Our 600-tadpole experiment used a fully-factorial design, rearing Atelopus varius tadpoles in water with either high (80mg/l CaCO3), medium (50mg/l CaCO3), or low calcium hardness (20mg/l CaCO3), each was combined with high (1.74 mg/l PO4) or low (0.36 mg/l PO4) phosphate levels. We found that calcium supplementation significantly improved tadpole survival from 19% to 49% and that low calcium treatments had 60% SLS that was reduced to about 15% at the medium and high calcium treatments. Phosphate supplementation significantly reduced SLS prevalence in low calcium treatments. This experimental research clearly links SLS to the calcium: phosphate homeostatic system, but we were unable to completely eliminate the issue, suggesting an interactive role of other unidentified factors., Competing Interests: D. Snellgrove is employed by by Waltham Petcare Science Institute, part of Mars Petcare UK. The Waltham Petcare Science Institute provided support in the form of salary for author DS, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section.
- Published
- 2020
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32. Response to Comment on "Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity".
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Scheele BC, Pasmans F, Skerratt LF, Berger L, Martel A, Beukema W, Acevedo AA, Burrowes PA, Carvalho T, Catenazzi A, De la Riva I, Fisher MC, Flechas SV, Foster CN, Frías-Álvarez P, Garner TWJ, Gratwicke B, Guayasamin JM, Hirschfeld M, Kolby JE, Kosch TA, La Marca E, Lindenmayer DB, Lips KR, Longo AV, Maneyro R, McDonald CA, Mendelson J 3rd, Palacios-Rodriguez P, Parra-Olea G, Richards-Zawacki CL, Rödel MO, Rovito SM, Soto-Azat C, Toledo LF, Voyles J, Weldon C, Whitfield SM, Wilkinson M, Zamudio KR, and Canessa S
- Subjects
- Amphibians, Animals, Biodiversity, Retrospective Studies, Chytridiomycota, Mycoses
- Abstract
Lambert et al question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species., (Copyright © 2020, American Association for the Advancement of Science.)
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- 2020
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33. Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity.
- Author
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Scheele BC, Pasmans F, Skerratt LF, Berger L, Martel A, Beukema W, Acevedo AA, Burrowes PA, Carvalho T, Catenazzi A, De la Riva I, Fisher MC, Flechas SV, Foster CN, Frías-Álvarez P, Garner TWJ, Gratwicke B, Guayasamin JM, Hirschfeld M, Kolby JE, Kosch TA, La Marca E, Lindenmayer DB, Lips KR, Longo AV, Maneyro R, McDonald CA, Mendelson J 3rd, Palacios-Rodriguez P, Parra-Olea G, Richards-Zawacki CL, Rödel MO, Rovito SM, Soto-Azat C, Toledo LF, Voyles J, Weldon C, Whitfield SM, Wilkinson M, Zamudio KR, and Canessa S
- Subjects
- Americas epidemiology, Animals, Anura classification, Australia epidemiology, Mycoses epidemiology, Anura microbiology, Anura physiology, Biodiversity, Chytridiomycota, Extinction, Biological, Mycoses veterinary
- Abstract
Anthropogenic trade and development have broken down dispersal barriers, facilitating the spread of diseases that threaten Earth's biodiversity. We present a global, quantitative assessment of the amphibian chytridiomycosis panzootic, one of the most impactful examples of disease spread, and demonstrate its role in the decline of at least 501 amphibian species over the past half-century, including 90 presumed extinctions. The effects of chytridiomycosis have been greatest in large-bodied, range-restricted anurans in wet climates in the Americas and Australia. Declines peaked in the 1980s, and only 12% of declined species show signs of recovery, whereas 39% are experiencing ongoing decline. There is risk of further chytridiomycosis outbreaks in new areas. The chytridiomycosis panzootic represents the greatest recorded loss of biodiversity attributable to a disease., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
- Published
- 2019
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34. The relationship between spindly leg syndrome incidence and water composition, overfeeding, and diet in newly metamorphosed harlequin frogs (Atelopus spp.).
- Author
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Camperio Ciani JF, Guerrel J, Baitchman E, Diaz R, Evans M, Ibáñez R, Ross H, Klaphake E, Nissen B, Pessier AP, Power ML, Arlotta C, Snellgrove D, Wilson B, and Gratwicke B
- Subjects
- Animal Feed adverse effects, Animal Nutritional Physiological Phenomena, Animals, Dietary Proteins adverse effects, Incidence, Metamorphosis, Biological, Animal Feed analysis, Animal Welfare statistics & numerical data, Bufonidae growth & development, Water analysis
- Abstract
Spindly Leg Syndrome (SLS) is a persistent animal welfare issue associated with the rearing of amphibians in captivity. We conducted two experiments to investigate the effects of diet, water composition and overfeeding on prevalence of SLS in newly metamorphosed harlequin frogs (Atelopus spp.). In our first experiment, we offered 400 full-sibling tadpoles of Atelopus certus isocaloric diets in treatments of 31%, 37%, 42% and 48% crude protein respectively. Tadpoles fed higher protein diets metamorphosed faster, but the incidence of SLS exceeded 80% in all treatments leading to the conclusion that variation in dietary protein was not responsible for causing SLS. We used 720 full-sibling Atelopus glyphus tadpoles in a second experiment to examine the effects of diet type, water composition and diet ration on SLS. We found that an overall incidence of 58% spindly leg in tadpoles reared in tap water, but reduced to about 10% in water treated by reverse osmosis and then reconstituted. It is possible that the reverse osmosis treatment removed some factor that caused the SLS, or that the reconstitution may have added a mineral lacking in the original tap water. Within tap water treatments, overfeeding tadpoles in tanks increased the incidence of SLS. We recommend further experimental research into this condition to identify the causative factors in the water. Additional research into the nutritional composition of food available to wild tadpoles would be useful in formulating captive diets, that have to date been solely based on surrogate species., Competing Interests: Donna Snellgrove is employed by Waltham Center for Pet Nutrition. This study was funded in part by First Quantum Minerals. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials.
- Published
- 2018
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35. BATRACHOCHYTRIUM DENDROBATIDIS IN A CAPTIVE COLLECTION OF GREEN SALAMANDERS ( ANEIDES AENEUS), LONG-TAILED SALAMANDERS ( EURYCEA LONGICAUDA), AND TWO-LINED SALAMANDERS ( EURYCEA BISLINEATA).
- Author
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Bauer KL, Steeil JC, Walsh TF, Evans MJ, Klocke B, Gratwicke B, Siegal-Willott JL, and Neiffer DL
- Subjects
- Animals, Animals, Zoo, Antifungal Agents therapeutic use, District of Columbia, Itraconazole therapeutic use, Mycoses drug therapy, Mycoses microbiology, Chytridiomycota isolation & purification, Disease Outbreaks veterinary, Disease Susceptibility, Mycoses veterinary, Urodela
- Abstract
A chytridiomycosis outbreak from Batrachochytrium dendrobatidis ( Bd) in a mixed-species plethodontid salamander exhibit resulted in four green salamander ( Aneides aeneus) deaths. One green salamander died before treatment, and three died during treatment with daily 0.005% itraconazole baths. All salamanders had evidence of severe Bd infections via cytology, histopathology, and/or polymerase chain reaction (PCR) at the time of death. Ten long-tailed salamanders ( Eurycea longicauda) and one two-lined salamander ( Eurycea bislineata) that shared the enclosure were initially negative for Bd on quantitative PCR but were prophylactically treated with daily 0.01% itraconazole baths for 11 days. Posttreatment testing yielded eight long-tailed salamanders and one two-lined salamander positive for Bd with low gene equivalents. All salamanders were negative after two to three treatment courses, and there were no additional mortalities. The difference in mortality and fungal load suggested that genus Aneides salamanders may be more susceptible to Bd than genus Eurycea salamanders.
- Published
- 2018
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36. Prodigiosin, Violacein, and Volatile Organic Compounds Produced by Widespread Cutaneous Bacteria of Amphibians Can Inhibit Two Batrachochytrium Fungal Pathogens.
- Author
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Woodhams DC, LaBumbard BC, Barnhart KL, Becker MH, Bletz MC, Escobar LA, Flechas SV, Forman ME, Iannetta AA, Joyce MD, Rabemananjara F, Gratwicke B, Vences M, and Minbiole KPC
- Subjects
- Animals, Antifungal Agents pharmacology, Anura microbiology, Bacteria classification, Bacteria isolation & purification, Biological Control Agents antagonists & inhibitors, Chytridiomycota growth & development, Chytridiomycota pathogenicity, Indoles chemistry, Microbial Sensitivity Tests, Panama, Phylogeny, Prodigiosin chemistry, Serratia classification, Serratia isolation & purification, Serratia metabolism, Skin microbiology, Switzerland, Symbiosis, United States, Volatile Organic Compounds chemistry, Bacteria metabolism, Chytridiomycota drug effects, Indoles antagonists & inhibitors, Indoles metabolism, Prodigiosin antagonists & inhibitors, Prodigiosin metabolism, Volatile Organic Compounds antagonists & inhibitors, Volatile Organic Compounds metabolism
- Abstract
Symbiotic bacteria can produce secondary metabolites and volatile compounds that contribute to amphibian skin defense. Some of these symbionts have been used as probiotics to treat or prevent the emerging disease chytridiomycosis. We examined 20 amphibian cutaneous bacteria for the production of prodigiosin or violacein, brightly colored defense compounds that pigment the bacteria and have characteristic spectroscopic properties making them readily detectable, and evaluated the antifungal activity of these compounds. We detected violacein from all six isolates of Janthinobacterium lividum on frogs from the USA, Switzerland, and on captive frogs originally from Panama. We detected prodigiosin from five isolates of Serratia plymuthica or S. marcescens, but not from four isolates of S. fonticola or S. liquefaciens. All J. lividum isolates produced violacein when visibly purple, while prodigiosin was only detected on visibly red Serratia isolates. When applied to cultures of chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), prodigiosin caused significant growth inhibition, with minimal inhibitory concentrations (MIC) of 10 and 50 μM, respectively. Violacein showed a MIC of 15 μM against both fungi and was slightly more active against Bsal than Bd at lower concentrations. Although neither violacein nor prodigiosin showed aerosol activity and is not considered a volatile organic compound (VOC), J. lividum and several Serratia isolates did produce antifungal VOCs. White Serratia isolates with undetectable prodigiosin levels could still inhibit Bd growth indicating additional antifungal compounds in their chemical arsenals. Similarly, J. lividum can produce antifungal compounds such as indole-3-carboxaldehyde in addition to violacein, and isolates are not always purple, or turn purple under certain growth conditions. When Serratia isolates were grown in the presence of cell-free supernatant (CFS) from the fungi, CFS from Bd inhibited growth of the prodigiosin-producing isolates, perhaps indicative of an evolutionary arms race; Bsal CFS did not inhibit bacterial growth. In contrast, growth of one J. lividum isolate was facilitated by CFS from both fungi. Isolates that grow and continue to produce antifungal compounds in the presence of pathogens may represent promising probiotics for amphibians infected or at risk of chytridiomycosis. In a global analysis, 89% of tested Serratia isolates and 82% of J. lividum isolates were capable of inhibiting Bd and these have been reported from anurans and caudates from five continents, indicating their widespread distribution and potential for host benefit.
- Published
- 2018
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37. Influence of extracellular environment on the motility and structural properties of spermatozoa collected from hormonally stimulated Panamanian Golden Frog (Atelopus zeteki).
- Author
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Della Togna G, Gratwicke B, Evans M, Augustine L, Chia H, Bronikowski E, Murphy JB, and Comizzoli P
- Subjects
- Animals, Chorionic Gonadotropin pharmacology, DNA Damage, Endangered Species, Gonadotropin-Releasing Hormone analogs & derivatives, Gonadotropin-Releasing Hormone pharmacology, Male, Metoclopramide pharmacology, Semen Analysis veterinary, Sperm Motility drug effects, Anura physiology, Spermatozoa physiology
- Abstract
A better understanding of the factors influencing the biology of amphibian spermatozoa after release from the testis is a prerequisite to the development of sperm preservation methods. The objective of the study was to determine the effect of extracellular conditions (exposure to water and different temperatures) over time on the sperm motility and structural properties (including morphology and DNA integrity) collected from hormonally stimulated Atelopus zeteki. Following intraperitoneal injection of gonadotropin-releasing hormone agonist (des-Gly
10 , D-Ala6 , Pro-NHEt9 GnRH; 4 μg/g of body weight), human chorionic gonadotropin (hCG, 10 IU/gbw), or Amphiplex™ (0.4 μg/gbw GnRH-A + 10 μg/gbw metoclopramide hydrochloride), spermic urine samples from 27 males were collected and analyzed for sperm motility, morphology and DNA integrity while maintained at room temperature (23 °C), 4 °C, or diluted in water (hypo-osmotic environment) over a period of 46 min post-collection. Percentages of sperm motility and forward progressive motility remained high (>60%) when spermic urine was kept at room temperature or at 4 °C for 46 min regardless of the hormonal stimulation method. Dilution in water at room temperature greatly reduced the percentage of motile spermatozoa and forward progression (<50%) as well as DNA integrity (32.8% of intact cells) after 23 min while morphology did not differ (30.4% of normal cells), regardless of the hormone stimulation. This is the first systematic study on the effect of extracellular environment over time on A. zeteki sperm quality. This will contribute to the development of sperm handling protocols and reproductive technologies for this and other endangered Atelopus species., (Published by Elsevier Inc.)- Published
- 2018
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38. Batrachochytrium salamandrivorans not detected in U.S. survey of pet salamanders.
- Author
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Klocke B, Becker M, Lewis J, Fleischer RC, Muletz-Wolz CR, Rockwood L, Aguirre AA, and Gratwicke B
- Subjects
- Animals, Biodiversity, Mycoses microbiology, Skin microbiology, Urodela classification, Chytridiomycota pathogenicity, Urodela microbiology
- Abstract
We engaged pet salamander owners in the United States to screen their animals for two amphibian chytrid fungal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). We provided pet owners with a sampling kit and instructional video to swab the skin of their animals. We received 639 salamander samples from 65 species by mail, and tested them for Bd and Bsal using qPCR. We detected Bd on 1.3% of salamanders (95% CI 0.0053-0.0267) and did not detect Bsal (95% CI 0.0000-0.0071). If Bsal is present in the U.S. population of pet salamanders, it occurs at a very low prevalence. The United States Fish and Wildlife Service listed 201 species of salamanders as "injurious wildlife" under the Lacey Act (18 U.S.C. § 42) on January 28, 2016, a precautionary action to prevent the introduction of Bsal to the U.S. through the importation of salamanders. This action reduced the number of salamanders imported to the U.S. from 2015 to 2016 by 98.4%. Our results indicate that continued precautions should be taken to prevent the introduction and establishment of Bsal in the U.S., which is a hotspot of salamander biodiversity.
- Published
- 2017
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39. Minimum lethal concentration of sodium hypochlorite for the amphibian pathogen Batrachochytrium dendrobatidis.
- Author
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Becker MH and Gratwicke B
- Subjects
- Amphibians, Animals, Dose-Response Relationship, Drug, Chytridiomycota drug effects, Disinfectants administration & dosage, Sodium Hypochlorite administration & dosage
- Abstract
Sodium hypochlorite (NaOCl) is the active ingredient in household bleach and is commonly used as a disinfectant to clean equipment contaminated by the amphibian pathogen Batrachochytrium dendrobatidis (Bd) in lab husbandry and field studies. We conducted a series of replicated exposure trials using a single Global Pandemic Lineage Bd isolate from Panama (JEL 310) and concentrations of NaOCl ranging from 0.006% to 0.6% for exposure times ranging from 30 seconds to 15 minutes to determine the minimum lethal concentration of NaOCl for this isolate of Bd. Sodium hypochlorite completely killed Bd at a concentration of 0.03% during a 15-minute exposure time, while 0.12% NaOCl was effective at all exposure times (30s-15min).
- Published
- 2017
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40. Effects of hormonal stimulation on the concentration and quality of excreted spermatozoa in the critically endangered Panamanian golden frog (Atelopus zeteki).
- Author
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Della Togna G, Trudeau VL, Gratwicke B, Evans M, Augustine L, Chia H, Bronikowski EJ, Murphy JB, and Comizzoli P
- Subjects
- Animals, Chorionic Gonadotropin pharmacology, Endangered Species, Gonadotropin-Releasing Hormone pharmacology, Male, Reproduction, Sperm Retrieval veterinary, Spermatozoa cytology, Spermatozoa physiology, Bufonidae physiology, Gonadotropin-Releasing Hormone agonists, Semen Analysis veterinary
- Abstract
Knowledge of basic gamete biology is critical to better protect and propagate endangered amphibian species and also to develop reproductive technologies combined with germplasm cryopreservation. The objectives of the study were to test different hormonal stimulations and then characterize the quantity and quality of Panamanian golden frog (Atelopus zeteki) spermatozoa. Following intraperitoneal injection of the gonadotropin-releasing hormone agonist (des-Gly
10 , D-Ala6 , Pro-NHEt9- -GnRH 1, 2 or 4 μg/g of body weight), human chorionic gonadotropin (hCG; 5 or 10 IU/gbw), or Amphiplex™ (0.4 μg/gbw GnRH-A + 10 μg/gbw metoclopramide hydrochloride), spermic urine samples from 29 males were collected at different time points (from 0.5 to 24 h post-injection) to analyze the concentration, motility, and morphology of the spermatozoa. Peak of sperm concentration was observed at 3.5 h post injection for all hormonal treatments. Amphiplex™ led to the highest sperm concentrations (4.45 ± 0.07 × 106 cells/mL) followed by 4 μg/gbw GnRH-A (2.65 ± 0.21 × 106 cells/mL). Other stimulation protocols and doses induced sperm production, but at lower levels (ranging from 1.34 to 1.70 × 106 cells/mL). More than 60% of spermatozoa were motile following all treatments but the highest motility (>90%) was obtained from the 10 IU/gbw hCG treatment. Spermic urine samples obtained with all hormone treatments had higher pH (ranging from 7.1 to 7.8) than the urine alone (6.7-6.8). Spermatozoa were filiform and elongated with an apical acrosome, a mitochondrial sheath, a small midpiece and a long tail with an undulating membrane. More than 80% of cells were morphologically normal and 50-70% had intact DNA. These sperm characteristics were not influenced by hormonal treatments. This first comprehensive characterization of sperm samples following optimized hormonal stimulations in A. zeteki lays the foundation for more fundamental studies, reproductive technologies, and future preservation strategies., (Copyright © 2016. Published by Elsevier Inc.)- Published
- 2017
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41. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen.
- Author
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Savage AE, Terrell KA, Gratwicke B, Mattheus NM, Augustine L, and Fleischer RC
- Abstract
The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1-15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29-55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations.
- Published
- 2016
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42. Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus.
- Author
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Becker MH, Walke JB, Cikanek S, Savage AE, Mattheus N, Santiago CN, Minbiole KP, Harris RN, Belden LK, and Gratwicke B
- Subjects
- Animals, Bacteria classification, Bacterial Proteins genetics, Bacterial Proteins metabolism, Microbiota, Molecular Sequence Data, Mycoses microbiology, Mycoses mortality, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Sequence Analysis, DNA, Bacteria genetics, Bufonidae physiology, Chytridiomycota physiology, Mycoses veterinary, Symbiosis
- Abstract
Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics., (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)
- Published
- 2015
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43. Evaluating group housing strategies for the ex-situ conservation of harlequin frogs (Atelopus spp.) using behavioral and physiological indicators.
- Author
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Cikanek SJ, Nockold S, Brown JL, Carpenter JW, Estrada A, Guerrel J, Hope K, Ibáñez R, Putman SB, and Gratwicke B
- Subjects
- Aggression, Animal Welfare, Animals, Bufonidae metabolism, Hydrocortisone metabolism, Male, Behavior, Animal, Bufonidae physiology, Conservation of Natural Resources methods, Housing, Animal
- Abstract
We have established ex situ assurance colonies of two endangered Panamanian harlequin frogs, Atelopus certus and Atelopus glyphus, but observed that males fought with each other when housed as a group. Housing frogs individually eliminated this problem, but created space constraints. To evaluate the potential stress effects from aggressive interactions when grouping frogs, we housed male frogs in replicated groups of one, two, and eight. We measured aggressive behavioral interactions and fecal glucocorticoid metabolite (GC) concentrations as indicators of stress in each tank. In both small and large groups, frogs initially interacted aggressively, but aggressive interactions and fecal GCs declined significantly after the first 2 weeks of being housed together, reaching the lowest levels by week 4. We conclude that aggressive interactions in same-sex groups of captive Atelopus may initially cause stress, but the frogs become habituated within a few weeks and they can safely be housed in same-sex groups for longer periods of time.
- Published
- 2014
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44. Stability of microbiota facilitated by host immune regulation: informing probiotic strategies to manage amphibian disease.
- Author
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Küng D, Bigler L, Davis LR, Gratwicke B, Griffith E, and Woodhams DC
- Subjects
- Amphibian Proteins physiology, Animals, Antimicrobial Cationic Peptides physiology, Anura microbiology, Dermatomycoses immunology, Disease Resistance, Host-Pathogen Interactions, Probiotics, Skin metabolism, Skin microbiology, Weight Loss immunology, Anura immunology, Bacillus physiology, Chytridiomycota immunology, Dermatomycoses veterinary, Microbiota immunology
- Abstract
Microbial communities can augment host immune responses and probiotic therapies are under development to prevent or treat diseases of humans, crops, livestock, and wildlife including an emerging fungal disease of amphibians, chytridiomycosis. However, little is known about the stability of host-associated microbiota, or how the microbiota is structured by innate immune factors including antimicrobial peptides (AMPs) abundant in the skin secretions of many amphibians. Thus, conservation medicine including therapies targeting the skin will benefit from investigations of amphibian microbial ecology that provide a model for vertebrate host-symbiont interactions on mucosal surfaces. Here, we tested whether the cutaneous microbiota of Panamanian rocket frogs, Colostethus panamansis, was resistant to colonization or altered by treatment. Under semi-natural outdoor mesocosm conditions in Panama, we exposed frogs to one of three treatments including: (1) probiotic - the potentially beneficial bacterium Lysinibacillus fusiformis, (2) transplant - skin washes from the chytridiomycosis-resistant glass frog Espadarana prosoblepon, and (3) control - sterile water. Microbial assemblages were analyzed by a culture-independent T-RFLP analysis. We found that skin microbiota of C. panamansis was resistant to colonization and did not differ among treatments, but shifted through time in the mesocosms. We describe regulation of host AMPs that may function to maintain microbial community stability. Colonization resistance was metabolically costly and microbe-treated frogs lost 7-12% of body mass. The discovery of strong colonization resistance of skin microbiota suggests a well-regulated, rather than dynamic, host-symbiont relationship, and suggests that probiotic therapies aiming to enhance host immunity may require an approach that circumvents host mechanisms maintaining equilibrium in microbial communities.
- Published
- 2014
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45. Cryptic impacts of temperature variability on amphibian immune function.
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Terrell KA, Quintero RP, Murray S, Kleopfer JD, Murphy JB, Evans MJ, Nissen BD, and Gratwicke B
- Subjects
- Aeromonas hydrophila immunology, Animals, Escherichia coli immunology, Linear Models, New York, Pseudomonas aeruginosa immunology, Seasons, Body Temperature physiology, Models, Immunological, Stress, Physiological immunology, Temperature, Urodela immunology
- Abstract
Ectothermic species living in temperate regions can experience rapid and potentially stressful changes in body temperature driven by abrupt weather changes. Yet, among amphibians, the physiological impacts of short-term temperature variation are largely unknown. Using an ex situ population of Cryptobranchus alleganiensis, an aquatic North American salamander, we tested the hypothesis that naturally occurring periods of temperature variation negatively impact amphibian health, either through direct effects on immune function or by increasing physiological stress. We exposed captive salamanders to repeated cycles of temperature fluctuations recorded in the population's natal stream and evaluated behavioral and physiological responses, including plasma complement activity (i.e. bacteria killing) against Pseudomonas aeruginosa, Escherichia coli and Aeromonas hydrophila. The best-fit model (ΔAICc=0, wi=0.9992) revealed 70% greater P. aeruginosa killing after exposure to variable temperatures and no evidence of thermal acclimation. The same model predicted 50% increased E. coli killing, but had weaker support (ΔAICc=1.8, wi=0.2882). In contrast, plasma defenses were ineffective against A. hydrophila, and other health indicators (leukocyte ratios, growth rates and behavioral patterns) were maintained at baseline values. Our data suggest that amphibians can tolerate, and even benefit from, natural patterns of rapid warming/cooling. Specifically, temperature variation can elicit increased activity of the innate immune system. This immune response may be adaptive in an unpredictable environment, and is undetectable by conventional health indicators (and hence considered cryptic). Our findings highlight the need to consider naturalistic patterns of temperature variation when predicting species' susceptibility to climate change.
- Published
- 2013
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46. Towards a better understanding of the use of probiotics for preventing chytridiomycosis in Panamanian golden frogs.
- Author
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Becker MH, Harris RN, Minbiole KP, Schwantes CR, Rollins-Smith LA, Reinert LK, Brucker RM, Domangue RJ, and Gratwicke B
- Subjects
- Animals, Antibiosis, Chytridiomycota pathogenicity, Dermatomycoses microbiology, Dermatomycoses prevention & control, Host-Pathogen Interactions, Oxalobacteraceae physiology, Bufonidae microbiology, Chytridiomycota isolation & purification, Dermatomycoses epidemiology, Dermatomycoses veterinary, Disease Outbreaks prevention & control, Disease Outbreaks veterinary, Probiotics therapeutic use
- Abstract
Populations of native Panamanian golden frogs (Atelopus zeteki) have collapsed due to a recent chytridiomycosis epidemic. Reintroduction efforts from captive assurance colonies are unlikely to be successful without the development of methods to control chytridiomycosis in the wild. In an effort to develop a protective treatment regimen, we treated golden frogs with Janthinobacterium lividum, a skin bacterium that has been used to experimentally prevent chytridiomycosis in North American amphibians. Although J. lividum appeared to colonize A. zeteki skin temporarily, it did not prevent or delay mortality in A. zeteki exposed to Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis. After introduction of J. lividum, average bacterial cell counts reached a peak of 1.7 × 10(6) cells per frog ~2 weeks after treatment but declined steadily after that. When J. lividum numbers declined to ~2.8 × 10(5) cells per frog, B. dendrobatidis infection intensity increased to greater than 13,000 zoospore equivalents per frog. At this point, frogs began to die of chytridiomycosis. Future research will concentrate on isolating and testing antifungal bacterial species from Panama that may be more compatible with Atelopus skin.
- Published
- 2011
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47. Attitudes toward consumption and conservation of tigers in China.
- Author
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Gratwicke B, Mills J, Dutton A, Gabriel G, Long B, Seidensticker J, Wright B, You W, and Zhang L
- Subjects
- Animals, Animals, Wild, China, Extinction, Biological, Conservation of Natural Resources, Public Opinion, Tigers
- Abstract
A heated debate has recently emerged between tiger farmers and conservationists about the potential consequences of lifting the ban on trade in farmed tiger products in China. This debate has caused unfounded speculation about the extent of the potential market for tiger products. To fill this knowledge gap, we surveyed 1880 residents from a total of six Chinese cities to understand Urban Chinese tiger consumption behavior, knowledge of trade issues and attitudes towards tiger conservation. We found that 43% of respondents had consumed some product alleged to contain tiger parts. Within this user-group, 71% said that they preferred wild products over farmed ones. The two predominant products used were tiger bone plasters (38%) and tiger bone wine (6.4%). 88% of respondents knew that it was illegal to buy or sell tiger products, and 93% agreed that a ban in trade of tiger parts was necessary to conserve wild tigers. These results indicate that while Urban Chinese people are generally supportive of tiger conservation, there is a huge residual demand for tiger products that could resurge if the ban on trade in tiger parts is lifted in China. We suspect that the current supply of the market is predominantly met by fakes or substitutes branded as tiger medicines, but not listing tiger as an ingredient. We suggest that the Traditional Chinese Medicine community should consider re-branding these products as bone-healing medicines in order to reduce the residual demand for real tiger parts over the long-term. The lifting of the current ban on trade in farmed tiger parts may cause a surge in demand for wild tiger parts that consumers say are better. Because of the low input costs associated with poaching, wild-sourced parts would consistently undercut the prices of farmed tigers that could easily be laundered on a legal market. We therefore recommend that the Chinese authorities maintain the ban on trade in tiger parts, and work to improve the enforcement of the existing ban.
- Published
- 2008
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48. The world can't have wild tigers and eat them, too.
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Gratwicke B, Bennett EL, Broad S, Christie S, Dutton A, Gabriel G, Kirkpatrick C, and Nowell K
- Subjects
- Animals, Bone and Bones, China, International Cooperation, Medicine, Chinese Traditional, Conservation of Natural Resources methods, Tigers physiology
- Published
- 2008
- Full Text
- View/download PDF
49. Poaching laws are useless without solid enforcement.
- Author
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Gratwicke B
- Subjects
- Animals, Conservation of Natural Resources trends, India, Population Density, Conservation of Natural Resources legislation & jurisprudence, Conservation of Natural Resources methods, Crime legislation & jurisprudence, Ecosystem, Tigers physiology
- Published
- 2007
- Full Text
- View/download PDF
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