Biokinetics and discrimination factors for δ13C and δ15N in the omnivorous freshwater crustacean, Cherax destructor

2012 ◽  
Vol 63 (10) ◽  
pp. 878 ◽  
Author(s):  
J. Veliscek Carolan ◽  
D. Mazumder ◽  
C. Dimovski ◽  
R. Diocares ◽  
J. Twining
Keyword(s):  
Food Web ◽  
Freshwater Ecosystems ◽  
Discrimination Factor ◽  
Δ13c And Δ15n ◽  
Web Studies ◽  
Cherax Destructor ◽  
Tissue Discrimination ◽  
Order Of Magnitude ◽  
Freshwater Crustacean ◽  
Discrimination Factors

Knowledge and understanding of biokinetics and discrimination factors for carbon-13 (δ13C) and nitrogen-15 (δ15N) are important when using stable isotopes for food-web studies. Therefore, we performed a controlled laboratory diet-switch experiment to examine diet–tissue and diet–faeces discrimination factors as well as the biokinetics of stable-isotope assimilation in the omnivorous freshwater crustacean, Cherax destructor. The biokinetics of δ13C could not be established; however, the δ15N value of C. destructor tissue reached equilibrium after 80 ± 35 days, with an estimated biological half-time for 15N of 19 ± 5 days. Metabolic activity contributed to the turnover of 15N by nearly an order of magnitude more than growth. The diet–tissue discrimination factors at the end of the exposure were estimated as –1.1 ± 0.5‰ for δ13C and +1.5 ± 1.0‰ for δ15N, indicating that a δ15N diet–tissue discrimination factor different from the typically assumed +3.4‰ may be required for freshwater macroinvertebrates such as C. destructor. The diet–faeces discrimination factor for δ15N after 120 days was estimated as +0.9 ± 0.5‰. The present study provides an increased understanding of the biokinetics and discrimination factors for a keystone freshwater macroinvertebrate that will be valuable for future food-web studies in freshwater ecosystems.

Diet–tissue discrimination factors of carbon and nitrogen stable isotopes in blood of Snowy Owl (Bubo scandiacus)

2011 ◽  
Vol 89 (4) ◽  
pp. 343-347 ◽  
Author(s):  
J.-F. Therrien ◽  
G. Fitzgerald ◽  
G. Gauthier ◽  
J. Bêty
Keyword(s):  
Stable Isotopes ◽  
Bird Species ◽  
Potential Effect ◽  
Mouse Muscle ◽  
Blood Samples ◽  
Web Studies ◽  
Tissue Discrimination ◽  
Discrimination Factors ◽  
Snowy Owl ◽  
Bubo Scandiacus

Analysis of carbon (13C/12C) and nitrogen (15N/14N) stable isotope ratios (hereafter δ13C and δ15N, respectively) in animal tissues is a powerful tool in food-web studies. However, isotopic ratios of prey are not transmitted directly to a consumer, as a diet–tissue discrimination factor (denoted Δ) occurs between sources and consumer’s tissues. An accurate assessment of the diet of a consumer with stable isotopes thus requires that the Δ13C and Δ15N of the studied species are known. Our aim was to establish Δ13C and Δ15N values in the Snowy Owl ( Bubo scandiacus (L., 1758)). Moreover, we assessed the potential effect of ethanol preservation of blood samples on δ13C and δ15N values. We kept four captive adult Snowy Owls on a pure diet of mice for ≥6 weeks. We then collected mouse muscle and blood samples from the owls and analyzed their δ13C and δ15N values. Δ13C and Δ15N values (mean ± SE) for owl blood were +0.3‰ ± 0.2‰ and +1.9‰ ± 0.1‰, respectively. These values are the first discrimination factors ever reported in Strigiformes and are lower, for Δ15N, than those obtained in terrestrial carnivores and other bird species, including falcons. Preservation in ethanol did not significantly affect δ13C and δ15N values.

Depth-specific and spatiotemporal variation of δ13C and δ15N in Charophytes of Lake Constance: implications for food web studies

2011 ◽  
Vol 25 (14) ◽  
pp. 2089-2094 ◽  
Author(s):  
Anja Matuszak ◽  
Christian C. Voigt ◽  
Ilse Storch ◽  
Hans-Günther Bauer ◽  
Petra Quillfeldt
Keyword(s):  
Food Web ◽  
Spatiotemporal Variation ◽  
Lake Constance ◽  
Δ13c And Δ15n ◽  
Web Studies

scholarly journals Variable δ15N Diet-Tissue Discrimination Factors among Sharks: Implications for Trophic Position, Diet and Food Web Models

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e77567 ◽  
Author(s):  
Jill A. Olin ◽  
Nigel E. Hussey ◽  
Alice Grgicak-Mannion ◽  
Mark W. Fritts ◽  
Sabine P. Wintner ◽  
...  
Keyword(s):  
Food Web ◽  
Trophic Position ◽  
Tissue Discrimination ◽  
Discrimination Factors

scholarly journals The parasitic chytrid, Zygorhizidium , facilitates the growth of the cladoceran zooplankter, Daphnia , in cultures of the inedible alga, Asterionella

2007 ◽  
Vol 274 (1617) ◽  
pp. 1561-1566 ◽  
Author(s):  
Maiko Kagami ◽  
Eric von Elert ◽  
Bas W Ibelings ◽  
Arnout de Bruin ◽  
Ellen Van Donk
Keyword(s):  
Food Web ◽  
Freshwater Ecosystems ◽  
Trophic Relationships ◽  
Transfer Energy ◽  
Free Swimming ◽  
Web Studies ◽  
Parasitic Fungi ◽  
Asterionella Formosa ◽  
Aquatic Food ◽  
Large Diatom

In food-web studies, parasites are often ignored owing to their insignificant biomass. We provide evidence that parasites may affect trophic transfer in aquatic food webs. Many phytoplankton species are susceptible to parasitic fungi (chytrids). Chytrid infections of diatoms in lakes may reach epidemic proportions during diatom spring blooms, so that numerous free-swimming fungal zoospores (2–3 μm in diameter) are produced. Analysis shows that these zoospores are rich in polyunsaturated fatty acids and sterols (particularly cholesterol), which indicates that they provide excellent food for zooplankters such as Daphnia . In life-table experiments using the large diatom Asterionella formosa as food, Daphnia growth increased significantly in treatments where a parasite was present. By grazing on the zoospores, Daphnia acquired important supplementary nutrients and were able to grow. When large inedible algae are infected by parasites, nutrients within the algal cells are consumed by these chytrids, some of which, in turn, are grazed by Daphnia . Thus, chytrids transfer energy and nutrients from their hosts to zooplankton. This study suggests that parasitic fungi alter trophic relationships in freshwater ecosystems and may be the important components in shaping the community and the food-web dynamics of lakes.

scholarly journals Current extinction rate in European freshwater gastropods greatly exceeds that of the late Cretaceous mass extinction

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas A. Neubauer ◽  
Torsten Hauffe ◽  
Daniele Silvestro ◽  
Jens Schauer ◽  
Dietrich Kadolsky ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Recovery Period ◽  
Freshwater Ecosystems ◽  
Extinction Rate ◽  
Freshwater Gastropods ◽  
Extinction Rates ◽  
Freshwater Biota ◽  
Order Of Magnitude ◽  
To Come ◽  
Mass Extinction Event

AbstractThe Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. However, previous studies based on vertebrates suggest that freshwater biota were much less affected. Here we assemble a time series of European freshwater gastropod species occurrences and inferred extinction rates covering the past 200 million years. We find that extinction rates increased by more than one order of magnitude during the Cretaceous–Paleogene mass extinction, which resulted in the extinction of 92.5% of all species. The extinction phase lasted 5.4 million years and was followed by a recovery period of 6.9 million years. However, present extinction rates in European freshwater gastropods are three orders of magnitude higher than even these revised estimates for the Cretaceous–Paleogene mass extinction. Our results indicate that, unless substantial conservation effort is directed to freshwater ecosystems, the present extinction crisis will have a severe impact to freshwater biota for millions of years to come.

scholarly journals The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca)

2013 ◽  
Vol 73 (4) ◽  
pp. 743-746
Author(s):  
E. Benedito ◽  
L. Figueroa ◽  
A.M Takeda ◽  
GI. Manetta
Keyword(s):  
Food Web ◽  
Native Species ◽  
Corbicula Fluminea ◽  
Cage Culture ◽  
Aquatic Food Web ◽  
Δ13c And Δ15n ◽  
Value Analysis ◽  
Fine Powders ◽  
Before And After ◽  
Aquatic Food

The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ13C and δ15N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filterer C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ13C) and nitrogen (δ15N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ13C and δ15N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ13C and δ15N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem.

scholarly journals The use of DNA barcodes in food web construction—terrestrial and aquatic ecologists unite!

Genome ◽  
2016 ◽  
Vol 59 (9) ◽  
pp. 603-628 ◽  
Author(s):  
Tomas Roslin ◽  
Sanna Majaneva
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Taxonomic Resolution ◽  
Dna Barcodes ◽  
Food Web Structure ◽  
Web Studies ◽  
Web Structure ◽  
Asking Questions ◽  
Web Construction ◽  
Interaction Webs

By depicting who eats whom, food webs offer descriptions of how groupings in nature (typically species or populations) are linked to each other. For asking questions on how food webs are built and work, we need descriptions of food webs at different levels of resolution. DNA techniques provide opportunities for highly resolved webs. In this paper, we offer an exposé of how DNA-based techniques, and DNA barcodes in particular, have recently been used to construct food web structure in both terrestrial and aquatic systems. We highlight how such techniques can be applied to simultaneously improve the taxonomic resolution of the nodes of the web (i.e., the species), and the links between them (i.e., who eats whom). We end by proposing how DNA barcodes and DNA information may allow new approaches to the construction of larger interaction webs, and overcome some hurdles to achieving adequate sample size. Most importantly, we propose that the joint adoption and development of these techniques may serve to unite approaches to food web studies in aquatic and terrestrial systems—revealing the extent to which food webs in these environments are structured similarly to or differently from each other, and how they are linked by dispersal.

The requirement for accurate diet-tissue discrimination factors for interpreting stable isotopes in sharks

Hydrobiologia ◽  
2010 ◽  
Vol 654 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Nigel E. Hussey ◽  
M. Aaron MacNeil ◽  
Aaron T. Fisk
Keyword(s):  
Stable Isotopes ◽  
Tissue Discrimination ◽  
Discrimination Factors

Tissue-diet discrimination factors of isotopic ratios (∆δ13C and ∆δ15N) in two brittle star species: Effect of reproductive state, diet and tissue composition

2012 ◽  
Vol 426-427 ◽  
pp. 68-77 ◽  
Author(s):  
Aline Blanchet-Aurigny ◽  
Monique Guillou ◽  
Fabrice Pernet ◽  
Jean-Dominique Gaffet ◽  
Stanislas F. Dubois
Keyword(s):  
Brittle Star ◽  
Isotopic Ratios ◽  
Tissue Composition ◽  
Reproductive State ◽  
Δ13c And Δ15n ◽  
Species Effect ◽  
Discrimination Factors
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