Amino Acid and Radiocarbon Insights From Captive Whale Sharks
Stable isotope analyses (SIA) have the potential to provide novel insights into spatial and temporal patterns in the trophic ecology of poorly understood organisms like whale sharks Rhincodon typus. However, interpreting SIA depends on accurate diet-tissue discrimination factors (DTDF) to quantify d...
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ftunivsthongkong:oai:repository.hkust.edu.hk:1783.1-98067 2023-07-30T03:59:29+02:00 Amino Acid and Radiocarbon Insights From Captive Whale Sharks Wyatt, Alex S.J. Matsumoto, Rui Chikaraishi, Yoshito Miyairi, Yousuke Yokoyama, Yusuke Sato, Keiichi Ohkouchi, Naohiko Nagata, Toshi 2016 https://repository.hkust.edu.hk/ir/Record/1783.1-98067 http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=&rft.volume=&rft.issue=&rft.date=2016&rft.spage=&rft.aulast=Wyatt&rft.aufirst=&rft.atitle=Amino%20Acid%20and%20Radiocarbon%20Insights%20From%20Captive%20Whale%20Sharks&rft.title=The%2010th%20International%20Conference%20on%20the%20Application%20of%20Stable%20Isotopes%20to%20Ecological%20Studies,%20Tokyo,%20Japan,%203%20-%208%20April%202016 English eng https://repository.hkust.edu.hk/ir/Record/1783.1-98067 http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=&rft.volume=&rft.issue=&rft.date=2016&rft.spage=&rft.aulast=Wyatt&rft.aufirst=&rft.atitle=Amino%20Acid%20and%20Radiocarbon%20Insights%20From%20Captive%20Whale%20Sharks&rft.title=The%2010th%20International%20Conference%20on%20the%20Application%20of%20Stable%20Isotopes%20to%20Ecological%20Studies,%20Tokyo,%20Japan,%203%20-%208%20April%202016 Conference paper 2016 ftunivsthongkong 2023-07-14T00:12:39Z Stable isotope analyses (SIA) have the potential to provide novel insights into spatial and temporal patterns in the trophic ecology of poorly understood organisms like whale sharks Rhincodon typus. However, interpreting SIA depends on accurate diet-tissue discrimination factors (DTDF) to quantify diets and trophic positions, with experimental derivations of DTDF rare for such large-bodied organisms. Captive R. typus have provided a unique opportunity to validate a range of SIA, compound-specific isotope analyses (CSIA) and radioisotope approaches in the world’s largest fish and one of three planktivorous sharks. Diet records over the past five years revealed a diet dominated by North Pacific and Antarctic krill, 44% and 49% of weighted diet for Euphausia pacifica and E. superba, respectively. Despite the well-known diet, SIA of fin tissue from three captive R. typus (7.1, 7.2, and 8.4 m in length) proved hard to reconcile, especially for bulk carbon. In contrast, CSIA of amino acid (AA) nitrogen in the sharks’ tissue was relatively stable over time, despite evidence of variation in AA compositions and δ15N-AA of diet components. Tissue radiocarbon further suggested either long turnover in fin tissues (27 months), or the preferential assimilation of the smaller E. pacifica (Δ14C of 3 ‰ compared to -112 ‰ for E. superba). Daily-scale analysis of radiocarbon in R. typus faeces may support the preferential assimilation hypothesis, faeces generally being depleted relative to diet. Together, CSIA-AA and radiocarbon analyses add multiple addtional axes to our isotope space and may alleviate some of the complications involved in interpreting bulk SIA in ecological studies. Conference Object Antarc* Antarctic Antarctic Krill The Hong Kong University of Science and Technology: HKUST Institutional Repository Antarctic Pacific |
institution |
Open Polar |
collection |
The Hong Kong University of Science and Technology: HKUST Institutional Repository |
op_collection_id |
ftunivsthongkong |
language |
English |
description |
Stable isotope analyses (SIA) have the potential to provide novel insights into spatial and temporal patterns in the trophic ecology of poorly understood organisms like whale sharks Rhincodon typus. However, interpreting SIA depends on accurate diet-tissue discrimination factors (DTDF) to quantify diets and trophic positions, with experimental derivations of DTDF rare for such large-bodied organisms. Captive R. typus have provided a unique opportunity to validate a range of SIA, compound-specific isotope analyses (CSIA) and radioisotope approaches in the world’s largest fish and one of three planktivorous sharks. Diet records over the past five years revealed a diet dominated by North Pacific and Antarctic krill, 44% and 49% of weighted diet for Euphausia pacifica and E. superba, respectively. Despite the well-known diet, SIA of fin tissue from three captive R. typus (7.1, 7.2, and 8.4 m in length) proved hard to reconcile, especially for bulk carbon. In contrast, CSIA of amino acid (AA) nitrogen in the sharks’ tissue was relatively stable over time, despite evidence of variation in AA compositions and δ15N-AA of diet components. Tissue radiocarbon further suggested either long turnover in fin tissues (27 months), or the preferential assimilation of the smaller E. pacifica (Δ14C of 3 ‰ compared to -112 ‰ for E. superba). Daily-scale analysis of radiocarbon in R. typus faeces may support the preferential assimilation hypothesis, faeces generally being depleted relative to diet. Together, CSIA-AA and radiocarbon analyses add multiple addtional axes to our isotope space and may alleviate some of the complications involved in interpreting bulk SIA in ecological studies. |
format |
Conference Object |
author |
Wyatt, Alex S.J. Matsumoto, Rui Chikaraishi, Yoshito Miyairi, Yousuke Yokoyama, Yusuke Sato, Keiichi Ohkouchi, Naohiko Nagata, Toshi |
spellingShingle |
Wyatt, Alex S.J. Matsumoto, Rui Chikaraishi, Yoshito Miyairi, Yousuke Yokoyama, Yusuke Sato, Keiichi Ohkouchi, Naohiko Nagata, Toshi Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
author_facet |
Wyatt, Alex S.J. Matsumoto, Rui Chikaraishi, Yoshito Miyairi, Yousuke Yokoyama, Yusuke Sato, Keiichi Ohkouchi, Naohiko Nagata, Toshi |
author_sort |
Wyatt, Alex S.J. |
title |
Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
title_short |
Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
title_full |
Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
title_fullStr |
Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
title_full_unstemmed |
Amino Acid and Radiocarbon Insights From Captive Whale Sharks |
title_sort |
amino acid and radiocarbon insights from captive whale sharks |
publishDate |
2016 |
url |
https://repository.hkust.edu.hk/ir/Record/1783.1-98067 http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=&rft.volume=&rft.issue=&rft.date=2016&rft.spage=&rft.aulast=Wyatt&rft.aufirst=&rft.atitle=Amino%20Acid%20and%20Radiocarbon%20Insights%20From%20Captive%20Whale%20Sharks&rft.title=The%2010th%20International%20Conference%20on%20the%20Application%20of%20Stable%20Isotopes%20to%20Ecological%20Studies,%20Tokyo,%20Japan,%203%20-%208%20April%202016 |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic Antarctic Krill |
genre_facet |
Antarc* Antarctic Antarctic Krill |
op_relation |
https://repository.hkust.edu.hk/ir/Record/1783.1-98067 http://lbdiscover.ust.hk/uresolver?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rfr_id=info:sid/HKUST:SPI&rft.genre=article&rft.issn=&rft.volume=&rft.issue=&rft.date=2016&rft.spage=&rft.aulast=Wyatt&rft.aufirst=&rft.atitle=Amino%20Acid%20and%20Radiocarbon%20Insights%20From%20Captive%20Whale%20Sharks&rft.title=The%2010th%20International%20Conference%20on%20the%20Application%20of%20Stable%20Isotopes%20to%20Ecological%20Studies,%20Tokyo,%20Japan,%203%20-%208%20April%202016 |
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1772810334295293952 |