The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Richard M. K. Saunders - One of the best experts on this subject based on the ideXlab platform.
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a symbiotic balancing act arbuscular mycorrhizal specificity and specialist fungus gnat pollination in the mycoheterotrophic genus thismia thismiaceae
Annals of Botany, 2019Co-Authors: X Guo, Shek Shing Mar, Zhongtao Zhao, Dianxiang Zhang, Richard M. K. SaundersAbstract:Background and aims Mycorrhizal associations in mycoheterotrophic plants are generally more specialized than in autotrophs. Mycoheterotrophs typically bear small, inconspicuous flowers that often self-pollinate to maximize seed set, although some have structurally complex flowers indicative of xenogamy. A trade-off has previously been proposed between specialization in these above- and below-ground symbioses, although empirical data are lacking. Methods We used next-generation DNA sequencing to compare the mycorrhizal communities from the roots of a mycoheterotrophic species, Thismia Tentaculata (Thismiaceae), and its neighbouring autotrophs. We furthermore conducted detailed assessments of floral phenology and pollination ecology, and performed artificial pollination experiments to determine the breeding system. Key results Thismia Tentaculata maintains a symbiotic association with a single arbuscular mycorrhizal Rhizophagus species. The flowers are pollinated by a single species of fungus gnats (Corynoptera, Sciaridae), which are attracted by the yellow pigments and are temporarily restrained within the perianth chamber before departing via apertures between the anthers. The plants are self-compatible but predominantly xenogamous. Conclusions Our findings demonstrate that T. Tentaculata maintains highly specialized associations with pollinators and mycorrhizal fungi, both of which are widely distributed. We suggest that specialization in multiple symbiotic interactions is possible in mycoheterotrophs if redundant selective pressures are not exerted to further restrict an already constrained suite of life-history traits.
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Thismia Tentaculata (Burmanniaceae tribe Thismieae) from Hong Kong: first record of the genus and tribe from continental China
Journal of Systematics and Evolution, 2009Co-Authors: Shek Shing Mar, Richard M. K. SaundersAbstract:Thismia Tentaculata (Burmanniaceae 部落 Thismieae ) 的人口在香港从傣族瞬间掸人被描述并且说明，南部的中国。这从大陆人中国代表类和部落的第一份报告。
Shek Shing Mar - One of the best experts on this subject based on the ideXlab platform.
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a symbiotic balancing act arbuscular mycorrhizal specificity and specialist fungus gnat pollination in the mycoheterotrophic genus thismia thismiaceae
Annals of Botany, 2019Co-Authors: X Guo, Shek Shing Mar, Zhongtao Zhao, Dianxiang Zhang, Richard M. K. SaundersAbstract:Background and aims Mycorrhizal associations in mycoheterotrophic plants are generally more specialized than in autotrophs. Mycoheterotrophs typically bear small, inconspicuous flowers that often self-pollinate to maximize seed set, although some have structurally complex flowers indicative of xenogamy. A trade-off has previously been proposed between specialization in these above- and below-ground symbioses, although empirical data are lacking. Methods We used next-generation DNA sequencing to compare the mycorrhizal communities from the roots of a mycoheterotrophic species, Thismia Tentaculata (Thismiaceae), and its neighbouring autotrophs. We furthermore conducted detailed assessments of floral phenology and pollination ecology, and performed artificial pollination experiments to determine the breeding system. Key results Thismia Tentaculata maintains a symbiotic association with a single arbuscular mycorrhizal Rhizophagus species. The flowers are pollinated by a single species of fungus gnats (Corynoptera, Sciaridae), which are attracted by the yellow pigments and are temporarily restrained within the perianth chamber before departing via apertures between the anthers. The plants are self-compatible but predominantly xenogamous. Conclusions Our findings demonstrate that T. Tentaculata maintains highly specialized associations with pollinators and mycorrhizal fungi, both of which are widely distributed. We suggest that specialization in multiple symbiotic interactions is possible in mycoheterotrophs if redundant selective pressures are not exerted to further restrict an already constrained suite of life-history traits.
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Thismia Tentaculata (Burmanniaceae tribe Thismieae) from Hong Kong: first record of the genus and tribe from continental China
Journal of Systematics and Evolution, 2009Co-Authors: Shek Shing Mar, Richard M. K. SaundersAbstract:Thismia Tentaculata (Burmanniaceae 部落 Thismieae ) 的人口在香港从傣族瞬间掸人被描述并且说明，南部的中国。这从大陆人中国代表类和部落的第一份报告。
G J Sandland - One of the best experts on this subject based on the ideXlab platform.
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spatial and temporal relationships between the invasive snail bithynia Tentaculata and submersed aquatic vegetation in pool 8 of the upper mississippi river
River Research and Applications, 2017Co-Authors: A M Weeks, N R De Jager, R J Haro, G J SandlandAbstract:Bithynia Tentaculata is an invasive snail that was first reported in Lake Michigan in 1871 and has since spread throughout a number of freshwater systems of the USA. This invasion has been extremely problematic in the Upper Mississippi River as the snails serve as intermediate hosts for several trematode parasites that have been associated with waterfowl mortality in the region. This study was designed to assess the abundance and distribution of B. Tentaculata relative to submersed aquatic vegetation as macrophytes provide important nesting and food resources for migrating waterfowl. Temporal changes in both vegetation and snail densities were compared between 2007 and 2015. Between these years, B. Tentaculata densities have nearly quadrupled despite minor changes in vegetation abundance, distribution and composition. Understanding the spatial distribution of B. Tentaculata in relation to other habitat features, including submersed vegetation, and quantifying any further changes in the abundance and distribution of B. Tentaculata over time will be important for better identifying areas of risk for disease transmission to waterfowl. Copyright © 2017 John Wiley & Sons, Ltd.
Gregory J. Sandland - One of the best experts on this subject based on the ideXlab platform.
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A Pilot Evaluation of the Toxicity of EarthTec® QZ on Invasive (Bithynia Tentaculata) and Native (Physa gyrina) Snail Species from the Upper Mississippi River
Bulletin of Environmental Contamination and Toxicology, 2018Co-Authors: Nadia Carmosini, Rick Gillis, Abdelrahman Ismail, Gregory J. SandlandAbstract:We used a comparative approach to investigate the effects of a copper-based pesticide (EarthTec® QZ) on embryos of an invasive snail ( Bithynia Tentaculata ) and a native snail ( Physa gyrina ). Embryos were exposed to one of three treatments: control (0 mg/L Cu^2+), low-dose (0.1 mg/L Cu^2+), or high-dose (0.6 mg/L Cu^2+), which reflect manufacturer-recommended low and medium 4-day molluscicide treatment concentrations. Exposure to 0.6 mg/L Cu^2+ over 4 days generated 100% mortality in both invasive and native snail embryos; however, reducing the exposure time from 4 to 1 day resulted in 100% mortality in B. Tentaculata but some hatching (7%) in P. gyrina . In contrast, embryos of both species exposed to 0.1 mg/L Cu^2+ treatment for 4 days showed almost 100% survivorship. Further manipulations of Cu^2+ concentrations and exposure times may yield regimes that maximize mortality in B. Tentaculata while minimizing negative impacts on native species.
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A Pilot Evaluation of the Toxicity of EarthTec® QZ on Invasive (Bithynia Tentaculata) and Native (Physa gyrina) Snail Species from the Upper Mississippi River
Bulletin of Environmental Contamination and Toxicology, 2018Co-Authors: Nadia Carmosini, Rick Gillis, Abdelrahman Ismail, Gregory J. SandlandAbstract:We used a comparative approach to investigate the effects of a copper-based pesticide (EarthTec® QZ) on embryos of an invasive snail ( Bithynia Tentaculata ) and a native snail ( Physa gyrina ). Embryos were exposed to one of three treatments: control (0 mg/L Cu^2+), low-dose (0.1 mg/L Cu^2+), or high-dose (0.6 mg/L Cu^2+), which reflect manufacturer-recommended low and medium 4-day molluscicide treatment concentrations. Exposure to 0.6 mg/L Cu^2+ over 4 days generated 100% mortality in both invasive and native snail embryos; however, reducing the exposure time from 4 to 1 day resulted in 100% mortality in B. Tentaculata but some hatching (7%) in P. gyrina . In contrast, embryos of both species exposed to 0.1 mg/L Cu^2+ treatment for 4 days showed almost 100% survivorship. Further manipulations of Cu^2+ concentrations and exposure times may yield regimes that maximize mortality in B. Tentaculata while minimizing negative impacts on native species.
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Assessing host competency between native and invasive snail species exposed to the native parasite Echinostoma revolutum.
Aquatic Invasions, 2014Co-Authors: Christopher Glodosky, Gregory J. SandlandAbstract:Invasive species have the ability to rapidly and extensively alter native ecosystems, and there is accumulating evidence to suggest that the introduction of invasive hosts can have influences on parasite transmission in native communities. In 2002, the aquatic snail Bithynia Tentaculata was discovered in the Upper Mississippi River (UMR) where it now co-occurs with several native snails and their parasites. The goal of this study was to determine the competencies of a native snail (Physa gyrina) and an invasive snail (B. Tentaculata) after controlled exposure to a native parasite species (Echinostoma revolutum). Results of our laboratory experiment indicated no difference in either the prevalence or intensity of infection between native and invasive snails, which was unexpected given past work on B. Tentaculata. In addition, infection had no discernible influence on host life-history traits such as growth and survival. Together, these results may have a number of consequences for hosts and parasites within the UMR region. First, the presence of an additional competent host in the snail assemblage may reduce infection risk for native snail species through parasite dilution. Second, the occurrence of a competent invasive host may increase the transmission of E. revolutum to native definitive host species such as waterfowl and mammals. Ultimately, a better understanding of how native parasites cycle through the UMR snail assemblage could allow us to better predict: 1) transmission/invasion outcomes in the UMR and 2) the potential alterations that may occur in ecosystems at high risk of B. Tentaculata invasion.
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Infection Patterns in Invasive and Native Snail Hosts Exposed to a Parasite Associated with Waterfowl Mortality in the Upper Mississippi River, USA
Journal of wildlife diseases, 2013Co-Authors: Gregory J. Sandland, Rick Gillis, Roger J. Haro, James PeirceAbstract:Bithynia Tentaculata is an aquatic invasive snail first detected in the upper Mississippi River (UMR) in 2002. The snail harbors a number of parasitic trematode species, including Sphaeridiotrema pseudoglobulus ,t hat have been implicated in waterfowl mortality in the region. We assessed the capacity of S. pseudoglobulus cercariae to infect B. Tentaculata and native snails found in the UMR. Four snail species (one invasive and three native) were individually exposed to S. pseudoglobulus larvae and all were successfully infected. A subsequent experiment examining infection patterns in inva- sive and native hosts exposed singly or in mixed treatments revealed no difference in parasite establishment among snail species. Our results add to our understanding of S. pseudoglobulus transmission and provide insight into processes underlying waterfowl disease in the UMR.
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Differential patterns of infection and life-history expression in native and invasive hosts exposed to a trematode parasite
Hydrobiologia, 2013Co-Authors: Gregory J. Sandland, Roger J. Haro, Stephen Houk, Benjamin Walker, Rick GillisAbstract:Non-indigenous species (NIS) are well-recognized as threats to biodiversity worldwide. Yet the interaction between NIS and disease emergence in native habitats remains poorly understood. Bithynia Tentaculata is an invasive aquatic snail which is now found in the Upper Mississippi River (UMR). A key concern with this snail is that it harbors trematode parasites (such as Sphaeridiotrema spp.) that have been associated with waterfowl mortality in the region. In this study, we used a combination of field collections and laboratory experiments to better understand the roles that infection competency and host life-history responses play in disease transmission in the UMR. Results from the field and laboratory showed that B. Tentaculata infected with Sphaeridiotrema spp. grew to a larger size than uninfected individuals. Although infection was not observed in a number of native species, results from this study suggest that they may still suffer exposure costs (such as reduced growth). Moreover, variability in infection competency between NIS and native snails may dilute or amplify host infection risk. This study reinforces the importance of considering both host life-history responses and competency in systems involving NIS, and provides insight into the factors potentially modulating waterfowl disease in the UMR.
A M Weeks - One of the best experts on this subject based on the ideXlab platform.
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spatial and temporal relationships between the invasive snail bithynia Tentaculata and submersed aquatic vegetation in pool 8 of the upper mississippi river
River Research and Applications, 2017Co-Authors: A M Weeks, N R De Jager, R J Haro, G J SandlandAbstract:Bithynia Tentaculata is an invasive snail that was first reported in Lake Michigan in 1871 and has since spread throughout a number of freshwater systems of the USA. This invasion has been extremely problematic in the Upper Mississippi River as the snails serve as intermediate hosts for several trematode parasites that have been associated with waterfowl mortality in the region. This study was designed to assess the abundance and distribution of B. Tentaculata relative to submersed aquatic vegetation as macrophytes provide important nesting and food resources for migrating waterfowl. Temporal changes in both vegetation and snail densities were compared between 2007 and 2015. Between these years, B. Tentaculata densities have nearly quadrupled despite minor changes in vegetation abundance, distribution and composition. Understanding the spatial distribution of B. Tentaculata in relation to other habitat features, including submersed vegetation, and quantifying any further changes in the abundance and distribution of B. Tentaculata over time will be important for better identifying areas of risk for disease transmission to waterfowl. Copyright © 2017 John Wiley & Sons, Ltd.
