Stable isotopes unravel the feeding mode‐trophic position relationship in trematode parasites

We measured the δ15N and δ13C stable isotopes of pelagic invertebrate predators in six central Ontario lakes, three invaded by Bythotrephes and three not invaded, to determine the effects of Bythotrephes invasion on diet overlap and trophic position of the predators. Seasonally averaged, lake-specific isotope signatures of bulk zooplankton were used as the isotopic baseline for determining nitrogen-based trophic position or carbon enrichment of the predators. Trophic positions of native Chaoborus , Leptodora , and Mysis in invaded lakes were not elevated compared with noninvaded lakes, suggesting that these predators do not feed directly on Bythotrephes. Nitrogen signatures of Mysis and Chaoborus were similar as were those of Leptodora and Bythotrephes, suggesting that invasion impacts will be greatest on Leptodora as has been observed. The trophic position of large Mysis was generally the highest and most variable of all predators, probably because it feeds on copepods that are more enriched in the heavier nitrogen isotope than bulk zooplankton and because Bythotrephes tends to decrease the ratio of cladocerans to copepods in invaded zooplankton communities.

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Levels of stored energy but not marine foraging patterns differentiate seasonal ecotypes of wild and hatchery steelhead (Oncorhynchus mykiss) returning to the Kalama River, Washington

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2016-0018 ◽

2017 ◽

Vol 74 (2) ◽

pp. 157-167 ◽

Cited By ~ 2

Author(s):

James S. Lamperth ◽

Thomas P. Quinn ◽

Mara S. Zimmerman

Keyword(s):

Stable Isotopes ◽

Oncorhynchus Mykiss ◽

Trophic Position ◽

Stored Energy ◽

Arrival Date ◽

Migration Distance ◽

Foraging Patterns ◽

Hatchery Fish ◽

Foraging Area ◽

Sufficient Energy

Anadromous fishes need to store sufficient energy at sea to migrate and reproduce, but the energetic demands of freshwater migration distance have been difficult to distinguish from the demands of fasting in fresh water prior to spawning. In addition, differences in stored energy may result from differences in metabolic storage or marine diet. We estimated somatic lipids (SL) and stable isotopes of N and C (as indices of marine trophic position and feeding location) in adult wild and hatchery steelhead (Oncorhynchus mykiss) of summer (stream-maturing) and winter (ocean-maturing) runs that migrate similar distances to spawn. We found that SL at return depended on several factors. Summer steelhead had twice the SL as winter steelhead, and within each run SL decreased with arrival date, converging on about 1% SL. In summer steelhead, females had 19% more SL than males, and wild fish had 21% more SL than hatchery fish. In winter steelhead, females had 27% less SL than males, and there was no difference between rearing origins. No differences were detected in δ15N or δ13C between ecotypes or rearing origins. Taken together, the results indicated different patterns of energy storage among and within ecotypes despite no apparent differences in marine trophic position or foraging area.

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Stable isotopes in jumbo squid (Dosidicus gigas) beaks to estimate its trophic position: comparison between stomach contents and stable isotopes

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406013324 ◽

2006 ◽

Vol 86 (2) ◽

pp. 437-445 ◽

Cited By ~ 53

Author(s):

R.I. Ruiz-Cooley ◽

Unai Markaida ◽

D. Gendron ◽

S. Aguíñiga

Keyword(s):

Stable Isotopes ◽

Stable Isotope ◽

Trophic Position ◽

Stomach Contents ◽

Isotope Ratios ◽

Trophic Relationships ◽

Dosidicus Gigas ◽

Jumbo Squid ◽

C And N ◽

Biomass Increase

Stomach contents and carbon (C) and nitrogen (N) stable isotope analysis were used to evaluate trophic relationships of jumbo squid, Dosidicus gigas. Buccal masses, beaks and stomach contents of large and medium maturing-sized jumbo squid and muscle from its main prey, the myctophid Benthosema panamense, were collected in the Gulf of California, Mexico during 1996, 1997 and 1999. Both the quantified C and N-isotope ratios in muscle, and stomach content analysis revealed that larger-sized maturing squid showed a higher trophic position than medium-sized individuals. However, a discrepancy between stomach contents versus stable isotope analyses was found in evaluating trophic relationships. Simple dilution models as a function of growth were used to estimate the C and N renewal dietary shift for jumbo squid. Estimates of the initial C and N pools in D. gigas with an initial age of 70 days and 210 days indicated isotopic shifts of 32% after a threefold biomass increase and 25% after a fourfold biomass increase, respectively. Additionally, beak samples of jumbo squid were evaluated as an alternative tissue to estimate squid trophic position using stable isotopes. The results showed a significant correlation between stable isotope ratios from muscle and beak samples. Muscle isotope values were higher than beak by 1% and 4% for δ13C and δ15N respectively. A test with jumbo squid beaks collected from a stomach of a stranded sperm whale confirmed the viability of this method.

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Extreme bill dimorphism leads to different but overlapping isotopic niches and similar trophic positions in sexes of the charismatic extinct huia

Oecologia ◽

10.1007/s00442-021-05082-8 ◽

2021 ◽

Author(s):

Barbara M. Tomotani ◽

Rodrigo B. Salvador ◽

Amandine J. M. Sabadel ◽

Colin M. Miskelly ◽

Julie C. S. Brown ◽

...

Keyword(s):

Amino Acids ◽

Stable Isotopes ◽

Geometric Morphometrics ◽

Foraging Behaviour ◽

Trophic Position ◽

Female Competition ◽

Museum Specimens ◽

Foraging Habitat ◽

Isotopic Analyses ◽

Trophic Niches

AbstractThe New Zealand huia (Heteralocha acutirostris) had the most extreme bill sexual dimorphism among modern birds. Given the quick extinction of the species, the cause of the dimorphism could only be hypothesised to reflect different trophic niches and reduce male/female competition. We tested that hypothesis by combining museum specimens, geometric morphometrics, and isotopic analyses. We used geometric morphometrics to describe bill shape; measured bulk (δ15Nbulk) and (δ13Cbulk) values from feather as proxies of the birds’ foraging habitat and diet; and compared compound-specific stable isotopes analyses (CSIA) of nitrogen in amino acids (δ15NAA) in male–female pairs to estimate their trophic position. Sexes had significantly different, but overlapping feather δ15Nbulk and δ13Cbulk values, but δ15NAA indicated identical trophic positions and δ15Nbulk was not related to bill shape. Trophic position was less variable among females, consistent with a specialised foraging behaviour and, thus, supporting a partial male/female foraging segregation.

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You are how you eat: differences in trophic position of two parasite species infecting a single host according to stable isotopes

Parasitology Research ◽

10.1007/s00436-020-06619-1 ◽

2020 ◽

Vol 119 (4) ◽

pp. 1393-1400 ◽

Cited By ~ 4

Author(s):

Beric M. Gilbert ◽

Milen Nachev ◽

Maik A. Jochmann ◽

Torsten C. Schmidt ◽

Daniel Köster ◽

...

Keyword(s):

Stable Isotopes ◽

Parasite Species ◽

Trophic Position ◽

Single Host

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Micronekton diel migration, community composition and trophic position within two biogeochemical provinces of the South West Indian Ocean: Insight from acoustics and stable isotopes

Deep Sea Research Part I Oceanographic Research Papers ◽

10.1016/j.dsr.2018.07.002 ◽

2018 ◽

Vol 138 ◽

pp. 85-97 ◽

Cited By ~ 9

Author(s):

P. Annasawmy ◽

J.F. Ternon ◽

F. Marsac ◽

Y. Cherel ◽

N. Béhagle ◽

...

Keyword(s):

Stable Isotopes ◽

Indian Ocean ◽

Community Composition ◽

Trophic Position ◽

The South ◽

Diel Migration ◽

South West Indian Ocean ◽

South West ◽

West Indian Ocean ◽

Biogeochemical Provinces

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Spatial variation in the stable isotopes of 13C and 15N and trophic position of Leporinus friderici (Characiformes, Anostomidae) in Corumbá Reservoir, Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652007000100006 ◽

2007 ◽

Vol 79 (1) ◽

pp. 41-49 ◽

Cited By ~ 2

Author(s):

Alexandre L. Pereira ◽

Evanilde Benedito ◽

Cássia M. Sakuragui

Keyword(s):

Stable Isotopes ◽

Carbon Source ◽

Isotopic Composition ◽

Spatial Variation ◽

Food Web ◽

Trophic Level ◽

Trophic Position ◽

Trophic Levels ◽

C3 Plants ◽

The One

Stable isotopes of carbon (delta13C) and nitrogen (delta15N) were used to describe sources of energy and trophic position for adult Leporinus friderici in the area of the Corumbá Reservoir, Brazil. Samples were collected from April 1999 to March 2000. Spatial variations were not identified in the isotopic composition. The maximum and minimum contribution of C4 plants calculated integrating the variation of plants and fish were 47.7% and 2.4%, respectively. Among C3 plants, periphyton presented closer isotopic values to those observed for fishes, corresponding to an important carbon source. The proportion of ingested plant item is larger in rivers upstream from the reservoir (42.7%), which justifies the smaller trophic level among there. However, in the reservoir, the ingestion of fish was 81.4%, while ingested plants contributed with 18.6%. Downstream from the dam, participation of plant item was even smaller (14.4%). Although the trophic position calculated with diet data was proportional to the one calculated with delta15N values, the former elevated the trophic level of L. friderici in the food web, because estimated trophic positions were based on fish items belonging to the 2nd (a) and to the 3rd (b) trophic levels.

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