Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets
Digestive efficiency (DE) is influenced by many factors including food type or quality. Assimilation efficiency (AE) and DE of 12 captive harp seals (Phoca groenlandica) were estimated for five prey types in large outdoor seawater tanks. In trials of > 9 days' duration, the seals were fed At...
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Canadian Science Publishing
1997
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crcansciencepubl:10.1139/z97-152 2024-04-28T08:05:27+00:00 Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets Lawson, John W. Miller, Edward H. Noseworthy, Elizabeth 1997 http://dx.doi.org/10.1139/z97-152 http://www.nrcresearchpress.com/doi/pdf/10.1139/z97-152 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 75, issue 8, page 1285-1291 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1997 crcansciencepubl https://doi.org/10.1139/z97-152 2024-04-09T06:56:28Z Digestive efficiency (DE) is influenced by many factors including food type or quality. Assimilation efficiency (AE) and DE of 12 captive harp seals (Phoca groenlandica) were estimated for five prey types in large outdoor seawater tanks. In trials of > 9 days' duration, the seals were fed Atlantic cod (Gadus morhua), Arctic cod (Boreogadus saida), Greenland halibut (Reinhardtius hippoglossoides), Atlantic herring (Clupea harengus), and capelin (Mallotus villosus). Fish were marked with inert tracers so that faecal samples could be matched to individual animals. AE (digestibility of dry matter) was estimated from the relative concentration of Mn 2+ in food and faeces. DE (digestible energy) was estimated from the relative concentrations of both Mn 2+ and energy in food and faeces. AE and DE values were high, but varied among the fish species (DE: Atlantic cod 93.5%; Arctic cod 93.5%; halibut 94.7%; capelin 95.7%; herring 96.6%). Both estimates of digestive efficiency were positively correlated with prey energy density. For most prey, AE and DE were not correlated with meal size, number of prey in a meal, size of prey, or seal body mass. However, digestive efficiency was greater in seals fed smaller Atlantic cod, or meals of greater mass. Quantifying estimates of digestive efficiency is important for formulating energy-based population consumption models, and so should be improved. It is recommended that more pinniped species be studied in captivity, that experiments last longer, and that the number of individuals studied be increased so that individual differences can be investigated. Article in Journal/Newspaper Arctic cod Arctic atlantic cod Boreogadus saida Gadus morhua Greenland Phoca groenlandica Canadian Science Publishing Canadian Journal of Zoology 75 8 1285 1291 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Lawson, John W. Miller, Edward H. Noseworthy, Elizabeth Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Digestive efficiency (DE) is influenced by many factors including food type or quality. Assimilation efficiency (AE) and DE of 12 captive harp seals (Phoca groenlandica) were estimated for five prey types in large outdoor seawater tanks. In trials of > 9 days' duration, the seals were fed Atlantic cod (Gadus morhua), Arctic cod (Boreogadus saida), Greenland halibut (Reinhardtius hippoglossoides), Atlantic herring (Clupea harengus), and capelin (Mallotus villosus). Fish were marked with inert tracers so that faecal samples could be matched to individual animals. AE (digestibility of dry matter) was estimated from the relative concentration of Mn 2+ in food and faeces. DE (digestible energy) was estimated from the relative concentrations of both Mn 2+ and energy in food and faeces. AE and DE values were high, but varied among the fish species (DE: Atlantic cod 93.5%; Arctic cod 93.5%; halibut 94.7%; capelin 95.7%; herring 96.6%). Both estimates of digestive efficiency were positively correlated with prey energy density. For most prey, AE and DE were not correlated with meal size, number of prey in a meal, size of prey, or seal body mass. However, digestive efficiency was greater in seals fed smaller Atlantic cod, or meals of greater mass. Quantifying estimates of digestive efficiency is important for formulating energy-based population consumption models, and so should be improved. It is recommended that more pinniped species be studied in captivity, that experiments last longer, and that the number of individuals studied be increased so that individual differences can be investigated. |
format |
Article in Journal/Newspaper |
author |
Lawson, John W. Miller, Edward H. Noseworthy, Elizabeth |
author_facet |
Lawson, John W. Miller, Edward H. Noseworthy, Elizabeth |
author_sort |
Lawson, John W. |
title |
Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
title_short |
Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
title_full |
Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
title_fullStr |
Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
title_full_unstemmed |
Variation in assimilation efficiency and digestive efficiency of captive harp seals ( Phoca groenlandica ) on different diets |
title_sort |
variation in assimilation efficiency and digestive efficiency of captive harp seals ( phoca groenlandica ) on different diets |
publisher |
Canadian Science Publishing |
publishDate |
1997 |
url |
http://dx.doi.org/10.1139/z97-152 http://www.nrcresearchpress.com/doi/pdf/10.1139/z97-152 |
genre |
Arctic cod Arctic atlantic cod Boreogadus saida Gadus morhua Greenland Phoca groenlandica |
genre_facet |
Arctic cod Arctic atlantic cod Boreogadus saida Gadus morhua Greenland Phoca groenlandica |
op_source |
Canadian Journal of Zoology volume 75, issue 8, page 1285-1291 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z97-152 |
container_title |
Canadian Journal of Zoology |
container_volume |
75 |
container_issue |
8 |
container_start_page |
1285 |
op_container_end_page |
1291 |
_version_ |
1797575480028692480 |