scholarly journals Tracking host use by bat ectoparasites with stable isotope analysis

2016 ◽  
Vol 94 (5) ◽  
pp. 353-360 ◽  
Author(s):  
Ulalume Hernández-Arciga ◽  
L. Gerardo Herrera M. ◽  
Juan B. Morales-Malacara
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Host Switching ◽  
Host Use ◽  
Higher Ed ◽  
The Difference ◽  
Anoura Geoffroyi ◽  
Leptonycteris Yerbabuenae ◽  
Host Parasite

We used C and N stable isotopes of nectarivorous bats and their ectoparasites to determine the extent to which parasites depend on the host individual for food. The difference in stable isotope values between parasites and host tissues (Δ13C and Δ15N) was used as a proxy of host use. First, we tested the hypothesis that movement among individual Mexican long-tongued bats (Choeronycteris mexicana Tschudi, 1844) is more likely to occur in winged flies than in mites as indicated by higher host–parasite isotopic Euclidian distance (ED). Second, we tested the hypothesis that ectoparasite species in two coexisting bat species representing the C3 (Geoffroy’s tailless bat, Anoura geoffroyi Gray, 1838) and the CAM (lesser long-nosed bat, Leptonycteris yerbabuenae Martínez and Villa-R., 1940) food chains were monoxenous as indicated by their isotopic values. We also examined Δ13C and Δ15N of individual parasites in relation to 13C and 15N reference enrichment factors as an indication of host switching. In general, flies in C. mexicana had higher ED and wider ranges of individual Δ13C and Δ15N than mites, suggesting that host switching occurred to a larger extent. Most ectoparasites species collected in both coexisting bats were monoxenous, but one fly species appears to be oligoxenous. Individual Δ13C and Δ15N values varied widely in these parasite species, suggesting movements within species hosts.

scholarly journals Allocation of endogenous nutrients for reproduction in the lesser long-nosed bat ( Leptonycteris yerbabuenae ) in central Mexico

2015 ◽  
Vol 97 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Gustavo Ramírez Hernández ◽  
L. Gerardo Herrera M.
Keyword(s):  
Stable Isotope ◽  
Deciduous Forest ◽  
Isotope Analysis ◽  
Late Summer ◽  
Evergreen Forest ◽  
Tropical Deciduous Forest ◽  
Central Mexico ◽  
Body Tissues ◽  
Lactating Females ◽  
Leptonycteris Yerbabuenae

Abstract In contrast to birds, the contribution of body reserves to sustain reproductive activities of migratory bats has not being examined. We used C stable isotope analysis to track the importance of nutrients stored in body tissues of the lesser long-nosed bat ( Leptonycteris yerbabuenae ) in Central Mexico. The bat migrates seasonally between areas dominated by vegetation types with contrasting C stable isotope values: in spring–summer, it forages in cactus forests before commuting to dry and wet forests, where mating and births occur. We collected breath and whole blood from nonreproductive individuals in a cactus forest in spring–mid-summer, from mating individuals in an evergreen forest in mid-late summer, and from lactating females in winter in a tropical deciduous forest. We also collected hair and milk from lactating females and several tissues from naturally aborted fetus in late autumn. We tested the hypothesis that nutrient reserves accumulated in cactus forest contribute to the maintenance of adults when they commute to their reproductive grounds, to the construction of offspring tissues during pregnancy, and to the production of milk. The importance of energy stores accumulated in cactus forests to fuel oxidative metabolism was marginal for mating males but it was high for some mating females. Nutrient stores accumulated in cactus forests contributed to ~50% of synthesis of fetus tissues but their contribution for milk production was negligible. Female lesser long-nosed bats can be described as capital-income breeders in relation to the development of offspring during gestation and as incomer breeders in relation to lactation. En contraste con las aves, la contribución de las reservas corporales para mantener las actividades reproductivas no ha sido evaluada en los murciélagos migratorios. En este estudio, usamos análisis de isótopos estables de C para reconstruir la importancia de los nutrientes almacenados en los tejidos del murciélago magueyero menor ( Leptonycteris yerbabuenae ) en el centro de México. Este murciélago migra estacionalmente entre áreas dominadas por tipos de vegetación con valores contrastantes de isótopos estables de C: la especie forrajea en bosques de cactáceas en primavera-verano antes de moverse a bosques secos y húmedos donde ocurren el apareamiento y los nacimientos. Se colectaron muestras de aliento y sangre entera de individuos no reproductivos en un bosque de cactáceas en primavera y mediados del verano, de individuos en etapa de apareamiento en un bosque húmedo a mediados y finales del verano, y de hembras lactantes en el invierno en un bosque seco tropical. Además, se colectaron muestras de pelo y leche de las hembras lactantes, y de varios tejidos de fetos a finales del otoño. Se probó la hipótesis de que las reservas de nutrientes acumuladas en el bosque de cactáceas contribuyen al mantenimiento de los adultos cuando se mueven a sus sitios de apareamiento, a la construcción de tejidos de las crías durante la preñez, y a la producción de leche. La importancia de las reservas de energía acumuladas en los bosques de cactáceas fue marginal para los machos y fue alta para algunas hembras durante el apareamiento. Los nutrientes acumulados en los bosques de cactáceas contribuyeron en hasta el 50% de la síntesis de tejidos de los fetos pero su contribución para la producción de leche fue de poca importancia. Las hembras de los murciélagos magueyeros menores siguen una estrategia reproductiva mixta de uso de reservas acumuladas y de nutrientes externos en relación al desarrollo de las crías durante la gestación, y una estrategia de uso de nutrientes externos en relación a la lactancia.

scholarly journals Triple stable isotope analysis to estimate the diet of the Velvet Scoter (Melanitta fusca) in the Baltic Sea

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5128 ◽  
Author(s):  
Rasa Morkūnė ◽  
Jūratė Lesutienė ◽  
Julius Morkūnas ◽  
Rūta Barisevičiūtė
Keyword(s):  
Stable Isotope ◽  
Baltic Sea ◽  
Isotope Analysis ◽  
Nitrogen Isotope ◽  
Enrichment Factors ◽  
Food Sources ◽  
Sandy Bottom ◽  
Sulphur Isotope ◽  
Winter Diet ◽  
Melanitta Fusca

This study quantifies contributions of different food sources in the winter diet of the Velvet Scoter (Melanitta fusca) in coastal waters of the Lithuanian Baltic Sea using non-lethal avian sampling. We highlight the application of stable sulphur isotope ratios as complementary to stable carbon and nitrogen isotope analysis in order to discriminate sandy bottom macrozoobenthos organisms as potential food sources for the Velvet Scoter. Selection of the most relevant trophic enrichment factors and Monte Carlo simulations in order to choose the best fitted model were undertaken. The stable isotope mixing model revealed the main contributions of a group of bivalves, Mya arenaria and Cerastoderma glaucum, to be 46–54%, and while the crustacean, Saduria entomon, comprised 26–35% of the diet.

scholarly journals Dry or Wet? Evaluating the Initial Rice Cultivation Environment on the Korean Peninsula

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 929
Author(s):  
Shinya Shoda ◽  
Hiroo Nasu ◽  
Kohei Yamazaki ◽  
Natsuki Murakami ◽  
Geon-Ju Na ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Bronze Age ◽  
Isotope Analysis ◽  
Nitrogen Isotope ◽  
Rice Cultivation ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
The Difference ◽  
Potential Factors ◽  
Cultivation Environment

The origins and development of rice cultivation are one of the most important aspects in studying agricultural and socio-economic innovations, as well as environmental change, in East Asian prehistory. In particular, whether wet or dry rice cultivation was conducted is an important consideration of its impact on societies and the environment across different periods and places. In this study, carbon and nitrogen stable isotope analysis of charred crop remains from archaeological sites dating from the Early Bronze Age (ca. 1.1k BC) to the Proto-Three Kingdoms (ca. 0.4 k AD) was conducted to clarify: (1) if there were any shifts from dry to wet cultivation around 1500 years after rice adoption as previously hypothesized and (2) the difference in stable carbon and nitrogen isotope values between rice and dry fields crops excavated from the same archaeological context to understand the cultivation environment. The result show that stable isotope values of charred rice grains have not changed significantly for around 1500 years. Moreover, rice possessed higher nitrogen stable isotope values than dry crops across all periods. While other potential factors could have influenced the 15N-enrichment of soils and crops, the most reasonable explanation is bacteriologic denitrification in anaerobic paddy soil where the rice was grown.

scholarly journals Multiple host use and the dynamics of host switching in host–parasite systems

2019 ◽  
Vol 12 (6) ◽  
pp. 511-522 ◽  
Author(s):  
Thomas Hovestadt ◽  
Jeremy A. Thomas ◽  
Oliver Mitesser ◽  
Karsten Schönrogge
Keyword(s):  
Host Switching ◽  
Host Use ◽  
Host Parasite

Quantifying the contribution of three competing pathways to total degradation in groundwater by a triple-isotope analysis approach

2020 ◽  
Author(s):  
Martin Thullner ◽  
Florian Centler ◽  
Thomas Hofstetter
Keyword(s):  
Stable Isotope ◽  
Isotope Fractionation ◽  
Environmental Science ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Theoretical Concept ◽  
Degradation Pathways ◽  
Theoretical Concepts ◽  
Dual Isotope ◽  
Stable Isotope Fractionation

<p>In groundwater and other environmental compartments, compound-specific stable isotope analysis (CSIA) has been used for the determination of specific degradation pathways by analyzing the stable isotopes of two elements. This ‘dual-isotope’ or two-dimensional isotope’ analysis also allows for an estimation of the contribution of two different pathways contributing both to the overall degradation and stable isotope fractionation. Heterogeneous groundwater flow patterns lead to some yet acceptable uncertainities in the results of this method.  Recent CSIA approaches also allow for investigating the simultaneous stable isotope fractionation effects for three different elements. Such information on the stable isotope fractionation of three different elements of a degradable compound could be used for a quantitative analysis of the contribution of different degradation pathways in systems with three different pathways, but up to know there is no theoretical concepts providing such quantitative estimate.</p><p>The aim of the present study is to overcome this shortage and to present such theoretical concept for the quantification of single pathway contribution to the overall biodegradation in groundwater and other systems with three parallel degradation pathways. For this purpose the approach of Centler et al. (2013) for the analysis of dual-isotope analysis has been expanded to consider the fractionation of three different elements affected by three different pathways. The obtained analytical expression allows for the quantification of each pathway to total degradation based stable isotope enrichment factors and measured stable isotope signatures. The applicability of the concept is demonstrated using data from Wijker et al. (2013).</p><p> </p><p>Centler, F., Hesse, F., and Thullner, M. (2013) Journal of Contaminant Hydrology, 152, 97-116.</p><p>Wijker, R. S., Bolotin, J., Nishino, S. F., Spain, J. C., and Hofstetter, T. B. (2013) Environmental Science & Technology, 47, 6872-6883.</p><p> </p>

Reactive transport of dichloromethane in laboratory aquifers: insights from dual-element isotope analysis and biomolecular approaches

2020 ◽  
Author(s):  
Maria Prieto Espinoza ◽  
Sylvain Weill ◽  
Benjamin Belfort ◽  
François Lehmann ◽  
Jérémy Masbou ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Water Table ◽  
Isotope Fractionation ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Degradation Pathways ◽  
Transient Conditions ◽  
Mass Removal ◽  
Water Table Fluctuations ◽  
Over Time

<p>Dichloromethane (DCM) is a toxic industrial solvent frequently detected in multi-contaminated aquifers. DCM often co-occurs with chlorinated ethenes resulting in complex mixtures posing challenges to predict its fate in groundwater. Changes in hydrochemistry and redox conditions in groundwater due to fluctuations in the water table may affect the extent and pathways of pollutant biodegradation. In this context, Compound-Specific Isotope Analysis (CSIA) is a useful tool to evaluate natural degradation of halogenated hydrocarbons. In this study, the impact of water table fluctuations on DCM biodegradation was examined in two laboratory aquifers using dual-element isotope analysis - the stable isotope fractionation of two elements (e.g., <sup>13</sup>C and <sup>37</sup>Cl), and high-throughput biomolecular approaches. The aquifers were supplied with contaminated groundwater from the former industrial site Thermeroil (France). High-resolution sampling and monitoring of pore water allowed examining, under steady and transient conditions, the aquifers response with respect to hydrochemistry and microbial composition. A dual C-Cl stable isotope approach (Λ<sup>C/Cl</sup> = Δδ<sup>13</sup>C/Δδ<sup>37</sup>Cl) was developed using GC-IRMS (C-DCM) and GC-MS (Cl-DCM) to estimate the extent of DCM degradation and to identify DCM degradation pathways. Under the experimental steady conditions, dissolved oxygen (<1.2 mg/L) and increasing Fe<sup>2+</sup> concentrations at lower depths of the aquifer models indicated iron-reducing prevailing conditions, while mass transfer of oxygen increased during water table fluctuations. Pronounced carbon isotope fractionation of DCM was associated with larger DCM mass removal under transient conditions (>90%) compared to steady conditions (mass removal of 35%). Under transient conditions, carbon enrichment factors (ε<sub>C</sub>) became larger over time ranging from -18.9 ± 3.4‰ to -33 ± 0.3‰ whereas chlorine enrichment factors (ε<sub>Cl</sub>) remained constant (-3.6 ± 0.7‰). In contrast, a similar ε<sub>C</sub> of -20 ± 3.5‰ (beginning of transient condition) but a larger ε<sub>Cl</sub> of -10.8 ± 2‰ were determined under steady conditions. As Λ<sup>C/Cl</sup> values are independent of complicating masking effects, and thus reflect reaction mechanisms, dual C-Cl isotope plots suggested distinct DCM degradation pathways under steady and transient conditions with Λ<sup>C/Cl</sup> values of 1.68 ± 0.26 and 3.41 ± 0.50, respectively. Even though a contribution of different mechanisms may take place during transient conditions, Λ<sup>C/Cl</sup> values fall in the range of S<sub>N</sub>1 pathways reported for <em>Ca.</em> Dichloromethanomonas elyunquensis (Λ<sup>C/Cl</sup> = 3.40 ± 0.03).  The distinct Λ<sup>C/Cl</sup> values may imply mechanistically distinct C-Cl bond cleavage reactions subjected to microbial adaptations during dynamic hydrogeological conditions. Although bacterial communities did not significantly change over time, the occurrence of <em>Geobacter</em> under both steady and transient conditions supports DCM degradation under iron-reducing prevailing conditions. Altogether, our results highlight that water table fluctuations enhance DCM biodegradation and influence DCM degradation pathways compared to steady conditions. This integrative study provides new insights into <em>in situ</em> degradation of DCM in contaminated aquifers and accounts the effects of dynamic water tables on DCM degradation.</p>

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