Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba
The Antarctic krill, Euphausia superba, is restricted to the Antarctic Ocean. The northern krill, Meganyctiphanes norvegica, is extremely widely distributed from the arctic North Atlantic to the warm Mediterranean. Respiration measurements showed no seasonal differences in rates determined in krill...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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2000
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Online Access: | http://dx.doi.org/10.1139/f00-168 http://www.nrcresearchpress.com/doi/pdf/10.1139/f00-168 |
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crcansciencepubl:10.1139/f00-168 2023-12-17T10:21:32+01:00 Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba Buchholz, Friedrich Saborowski, Reinhard 2000 http://dx.doi.org/10.1139/f00-168 http://www.nrcresearchpress.com/doi/pdf/10.1139/f00-168 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 57, issue S3, page 115-129 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2000 crcansciencepubl https://doi.org/10.1139/f00-168 2023-11-19T13:39:29Z The Antarctic krill, Euphausia superba, is restricted to the Antarctic Ocean. The northern krill, Meganyctiphanes norvegica, is extremely widely distributed from the arctic North Atlantic to the warm Mediterranean. Respiration measurements showed no seasonal differences in rates determined in krill from the thermally stable Clyde Sea (Scotland) and the cooler but variable Danish Kattegat. In the warm Ligurian Sea, where temperatures are stable, krill showed higher rates in April than in September, indicating reactions to the short but intensive productive season. Krill can passively benefit from enhancements of overall metabolism when ascending into upper, warmer water strata during their pronounced diel vertical migration. Michaelis-Menten constants (K m ) of citrate synthase (CS) were compared. In terms of respiration and enzyme regulation, krill from the Ligurian Sea stand apart: temperature and nutrition appear to be of different influence, relatable to genetic differentiation in the species. In contrast, K m of CS in E. superba is temperature independent, highlighting the species' stenothermal physiology. A basal level of activity of digestive enzymes ensures immediate utilization of patchy food sources. Specific induction, including that of chitinases, indicating omnivory in both species, underlines krill's exceptional capacity to adapt to highly variable trophic environments. Processes of moult, growth, and reproduction are locally and seasonally adjusted. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Antarctic Ocean Arctic Euphausia superba Meganyctiphanes norvegica North Atlantic Northern krill Canadian Science Publishing (via Crossref) Arctic Antarctic The Antarctic Antarctic Ocean Kattegat ENVELOPE(9.692,9.692,63.563,63.563) Canadian Journal of Fisheries and Aquatic Sciences 57 S3 115 129 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Buchholz, Friedrich Saborowski, Reinhard Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
The Antarctic krill, Euphausia superba, is restricted to the Antarctic Ocean. The northern krill, Meganyctiphanes norvegica, is extremely widely distributed from the arctic North Atlantic to the warm Mediterranean. Respiration measurements showed no seasonal differences in rates determined in krill from the thermally stable Clyde Sea (Scotland) and the cooler but variable Danish Kattegat. In the warm Ligurian Sea, where temperatures are stable, krill showed higher rates in April than in September, indicating reactions to the short but intensive productive season. Krill can passively benefit from enhancements of overall metabolism when ascending into upper, warmer water strata during their pronounced diel vertical migration. Michaelis-Menten constants (K m ) of citrate synthase (CS) were compared. In terms of respiration and enzyme regulation, krill from the Ligurian Sea stand apart: temperature and nutrition appear to be of different influence, relatable to genetic differentiation in the species. In contrast, K m of CS in E. superba is temperature independent, highlighting the species' stenothermal physiology. A basal level of activity of digestive enzymes ensures immediate utilization of patchy food sources. Specific induction, including that of chitinases, indicating omnivory in both species, underlines krill's exceptional capacity to adapt to highly variable trophic environments. Processes of moult, growth, and reproduction are locally and seasonally adjusted. |
format |
Article in Journal/Newspaper |
author |
Buchholz, Friedrich Saborowski, Reinhard |
author_facet |
Buchholz, Friedrich Saborowski, Reinhard |
author_sort |
Buchholz, Friedrich |
title |
Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
title_short |
Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
title_full |
Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
title_fullStr |
Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
title_full_unstemmed |
Metabolic and enzymatic adaptations in northern krill, Meganyctiphanes norvegica , and Antarctic krill, Euphausia superba |
title_sort |
metabolic and enzymatic adaptations in northern krill, meganyctiphanes norvegica , and antarctic krill, euphausia superba |
publisher |
Canadian Science Publishing |
publishDate |
2000 |
url |
http://dx.doi.org/10.1139/f00-168 http://www.nrcresearchpress.com/doi/pdf/10.1139/f00-168 |
long_lat |
ENVELOPE(9.692,9.692,63.563,63.563) |
geographic |
Arctic Antarctic The Antarctic Antarctic Ocean Kattegat |
geographic_facet |
Arctic Antarctic The Antarctic Antarctic Ocean Kattegat |
genre |
Antarc* Antarctic Antarctic Krill Antarctic Ocean Arctic Euphausia superba Meganyctiphanes norvegica North Atlantic Northern krill |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctic Ocean Arctic Euphausia superba Meganyctiphanes norvegica North Atlantic Northern krill |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 57, issue S3, page 115-129 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f00-168 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
57 |
container_issue |
S3 |
container_start_page |
115 |
op_container_end_page |
129 |
_version_ |
1785535736424955904 |