Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition
© 2004 Inter-Research DOI:10.3354/meps266043 Stable nitrogen isotope ratios are routinely used to disentangle trophic relationships. Several authors have discussed factors in addition to diet that might contribute to variability in δ¹⁵N of consumers, but few studies have explored such factors in det...
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Online Access: | http://hdl.handle.net/1853/43099 https://doi.org/10.3354/meps266043 |
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ftgeorgiatech:oai:repository.gatech.edu:1853/43099 2024-06-02T08:14:50+00:00 Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition Schmidt, Katrin McClelland, James W. Mente, Eleni Montoya, Joseph P. Atkinson, Angus Voss, Maren Universität Rostock. Institut für Ostseeforschung Warnemünde Georgia Institute of Technology. School of Biology University of Aberdeen. Dept. of Zoology British Antarctic Survey Marine Biological Laboratory (Woods Hole, Mass.) 2004-01-30 application/pdf http://hdl.handle.net/1853/43099 https://doi.org/10.3354/meps266043 en_US eng Georgia Institute of Technology Inter-Research Schmidt, K., J.W. McClelland, E. Mente, J.P. Montoya, A. Atkinson, and M. Voss. 2004 Trophic-level interpretation based on delta N-15 values: Implications of tissue-specific fractionation and amino acid composition. Marine Ecology Progress Series 266: 43-58. doi:10.3354/meps266043 0171-8630 http://hdl.handle.net/1853/43099 Stable isotopes δ¹⁵N Amino acids Tissue Euphausia superb Male Female Text Article 2004 ftgeorgiatech https://doi.org/10.3354/meps266043 2024-05-06T11:07:31Z © 2004 Inter-Research DOI:10.3354/meps266043 Stable nitrogen isotope ratios are routinely used to disentangle trophic relationships. Several authors have discussed factors in addition to diet that might contribute to variability in δ¹⁵N of consumers, but few studies have explored such factors in detail. For a better understanding of tissue-specific differences in δ¹⁵N, we examined postlarval euphausiids across a variety of seasons and regions in the Southern Ocean. The concentration and δ¹⁵N of individual amino acids were analysed to account for both the biochemical and physiological underpinnings of the observed bulk δ¹⁵N. Euphausiids showed consistent d15N differences of 1 to 2 ” between the digestive gland and abdominal segment, and between reproductively active males and females. These differences in bulk δ¹⁵N were accompanied by variations in relative proportions of amino acids (up to 5 mol %) and their δ¹⁵N (up to 11‰). Aspartic acid and glutamic acid had the strongest influence on bulk δ¹⁵N, due to their high abundance and variable δ¹⁵N values. Differences in relative proportions and/or δ¹⁵N of glycine alanine were also important for bulk δ¹⁵N values. Isotopic variations in amino acids between gender and tissues were explained by dominant internal processes such as protein synthesis or degradation for energy supply, and by differences in amino acid pool sizes. Despite the offset in bulk δ¹⁵N between females and males, several lines of evidence suggested that their trophic levels were similar. Thus, specific amino acid composition and metabolism may confound trophic level interpretations of bulk δ¹⁵N values. Micronekton are normally analyzed whole in isotopic studies, and we suggest that their analyses should be restricted to comparable tissues such as muscles. Article in Journal/Newspaper Southern Ocean Georgia Institute of Technology: SMARTech - Scholarly Materials and Research at Georgia Tech Southern Ocean Marine Ecology Progress Series 266 43 58 |
institution |
Open Polar |
collection |
Georgia Institute of Technology: SMARTech - Scholarly Materials and Research at Georgia Tech |
op_collection_id |
ftgeorgiatech |
language |
English |
topic |
Stable isotopes δ¹⁵N Amino acids Tissue Euphausia superb Male Female |
spellingShingle |
Stable isotopes δ¹⁵N Amino acids Tissue Euphausia superb Male Female Schmidt, Katrin McClelland, James W. Mente, Eleni Montoya, Joseph P. Atkinson, Angus Voss, Maren Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
topic_facet |
Stable isotopes δ¹⁵N Amino acids Tissue Euphausia superb Male Female |
description |
© 2004 Inter-Research DOI:10.3354/meps266043 Stable nitrogen isotope ratios are routinely used to disentangle trophic relationships. Several authors have discussed factors in addition to diet that might contribute to variability in δ¹⁵N of consumers, but few studies have explored such factors in detail. For a better understanding of tissue-specific differences in δ¹⁵N, we examined postlarval euphausiids across a variety of seasons and regions in the Southern Ocean. The concentration and δ¹⁵N of individual amino acids were analysed to account for both the biochemical and physiological underpinnings of the observed bulk δ¹⁵N. Euphausiids showed consistent d15N differences of 1 to 2 ” between the digestive gland and abdominal segment, and between reproductively active males and females. These differences in bulk δ¹⁵N were accompanied by variations in relative proportions of amino acids (up to 5 mol %) and their δ¹⁵N (up to 11‰). Aspartic acid and glutamic acid had the strongest influence on bulk δ¹⁵N, due to their high abundance and variable δ¹⁵N values. Differences in relative proportions and/or δ¹⁵N of glycine alanine were also important for bulk δ¹⁵N values. Isotopic variations in amino acids between gender and tissues were explained by dominant internal processes such as protein synthesis or degradation for energy supply, and by differences in amino acid pool sizes. Despite the offset in bulk δ¹⁵N between females and males, several lines of evidence suggested that their trophic levels were similar. Thus, specific amino acid composition and metabolism may confound trophic level interpretations of bulk δ¹⁵N values. Micronekton are normally analyzed whole in isotopic studies, and we suggest that their analyses should be restricted to comparable tissues such as muscles. |
author2 |
Universität Rostock. Institut für Ostseeforschung Warnemünde Georgia Institute of Technology. School of Biology University of Aberdeen. Dept. of Zoology British Antarctic Survey Marine Biological Laboratory (Woods Hole, Mass.) |
format |
Article in Journal/Newspaper |
author |
Schmidt, Katrin McClelland, James W. Mente, Eleni Montoya, Joseph P. Atkinson, Angus Voss, Maren |
author_facet |
Schmidt, Katrin McClelland, James W. Mente, Eleni Montoya, Joseph P. Atkinson, Angus Voss, Maren |
author_sort |
Schmidt, Katrin |
title |
Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
title_short |
Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
title_full |
Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
title_fullStr |
Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
title_full_unstemmed |
Trophic-level interpretation based on δ¹⁵N values: implications of tissue-specific fractionation and amino acid composition |
title_sort |
trophic-level interpretation based on δ¹⁵n values: implications of tissue-specific fractionation and amino acid composition |
publisher |
Georgia Institute of Technology |
publishDate |
2004 |
url |
http://hdl.handle.net/1853/43099 https://doi.org/10.3354/meps266043 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Schmidt, K., J.W. McClelland, E. Mente, J.P. Montoya, A. Atkinson, and M. Voss. 2004 Trophic-level interpretation based on delta N-15 values: Implications of tissue-specific fractionation and amino acid composition. Marine Ecology Progress Series 266: 43-58. doi:10.3354/meps266043 0171-8630 http://hdl.handle.net/1853/43099 |
op_doi |
https://doi.org/10.3354/meps266043 |
container_title |
Marine Ecology Progress Series |
container_volume |
266 |
container_start_page |
43 |
op_container_end_page |
58 |
_version_ |
1800738816091226112 |