The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula
The overwinter survival mechanisms of Antarctic krill, Euphausia superba, are poorly characterized, especially for juveniles. It has been suggested that juveniles adopt a mix of strategies characteristic of both larvae and adults. Like larvae, they may feed opportunistically throughout winter when f...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-12-01
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| Series: | Frontiers in Marine Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2022.1009385/full |
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| author | Kirsten B. Steinke Kim S. Bernard Julia M. Fontana Louise A. Copeman Lani M. Garcia |
| author_facet | Kirsten B. Steinke Kim S. Bernard Julia M. Fontana Louise A. Copeman Lani M. Garcia |
| author_sort | Kirsten B. Steinke |
| collection | DOAJ |
| description | The overwinter survival mechanisms of Antarctic krill, Euphausia superba, are poorly characterized, especially for juveniles. It has been suggested that juveniles adopt a mix of strategies characteristic of both larvae and adults. Like larvae, they may feed opportunistically throughout winter when food is available, and like adults they may be able to suppress their metabolism when food is scarce. In this study we look at the overwinter strategies of juvenile krill and how their reproductive development changes when energy input exceeds what is necessary for survival. We take a closer look at how the sexual maturation of juvenile krill progresses in response to different environmental conditions throughout the fall and winter. We exposed juvenile Antarctic krill to four different “food environment scenarios”, supplementing them with various diets from May to September 2019 that were representative of environmental conditions that they may encounter in different regions of the Western Antarctic Peninsula during autumn and winter. Each month, we measured the physiology and condition of the krill, and assessed the reproductive development of females. We found that when female juvenile krill have greater energy reserves than what is needed to survive the winter, they will begin to sexually mature. Further, when there are sufficient levels of the fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and 16:4 (n-1), krill are likely to be in a more reproductive advanced stage. However, when lipids, EPA, DHA and 16:4 (n-1) are depleted throughout the winter, juvenile female krill lose their ability to develop reproductively. We also found that sexual development is an energy intensive process that requires high respiration rates in juvenile krill. Furthermore, when juvenile females expend energy maturing, their physiological condition declines. This trade-off between early reproductive development and condition in juvenile female krill has important implications for individual health and population fecundity. Gaining a better understanding of the mechanisms behind juvenile krill winter survival strategies and their consequences will allow us to predict how future change at the western Antarctic Peninsula may affect krill population dynamics, especially in light of a warming climate. |
| first_indexed | 2024-04-13T07:04:39Z |
| format | Article |
| id | doaj.art-ac69d2e684ea4eefb2ab181a11cd25ee |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-04-13T07:04:39Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-ac69d2e684ea4eefb2ab181a11cd25ee2022-12-22T02:57:01ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452022-12-01910.3389/fmars.2022.10093851009385The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic PeninsulaKirsten B. Steinke0Kim S. Bernard1Julia M. Fontana2Louise A. Copeman3Lani M. Garcia4College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, United StatesCollege of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, United StatesCollege of Earth, Ocean, and Environment, University of Delaware, Newark, DE, United StatesAlaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Hatfield Marine Science Center, Newport, OR, United StatesCollege of Science, Oregon State University, Corvallis, OR, United StatesThe overwinter survival mechanisms of Antarctic krill, Euphausia superba, are poorly characterized, especially for juveniles. It has been suggested that juveniles adopt a mix of strategies characteristic of both larvae and adults. Like larvae, they may feed opportunistically throughout winter when food is available, and like adults they may be able to suppress their metabolism when food is scarce. In this study we look at the overwinter strategies of juvenile krill and how their reproductive development changes when energy input exceeds what is necessary for survival. We take a closer look at how the sexual maturation of juvenile krill progresses in response to different environmental conditions throughout the fall and winter. We exposed juvenile Antarctic krill to four different “food environment scenarios”, supplementing them with various diets from May to September 2019 that were representative of environmental conditions that they may encounter in different regions of the Western Antarctic Peninsula during autumn and winter. Each month, we measured the physiology and condition of the krill, and assessed the reproductive development of females. We found that when female juvenile krill have greater energy reserves than what is needed to survive the winter, they will begin to sexually mature. Further, when there are sufficient levels of the fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and 16:4 (n-1), krill are likely to be in a more reproductive advanced stage. However, when lipids, EPA, DHA and 16:4 (n-1) are depleted throughout the winter, juvenile female krill lose their ability to develop reproductively. We also found that sexual development is an energy intensive process that requires high respiration rates in juvenile krill. Furthermore, when juvenile females expend energy maturing, their physiological condition declines. This trade-off between early reproductive development and condition in juvenile female krill has important implications for individual health and population fecundity. Gaining a better understanding of the mechanisms behind juvenile krill winter survival strategies and their consequences will allow us to predict how future change at the western Antarctic Peninsula may affect krill population dynamics, especially in light of a warming climate.https://www.frontiersin.org/articles/10.3389/fmars.2022.1009385/fullAntarctic krillreproductionenergyjuveniletrade-offbody condition |
| spellingShingle | Kirsten B. Steinke Kim S. Bernard Julia M. Fontana Louise A. Copeman Lani M. Garcia The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula Frontiers in Marine Science Antarctic krill reproduction energy juvenile trade-off body condition |
| title | The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula |
| title_full | The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula |
| title_fullStr | The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula |
| title_full_unstemmed | The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula |
| title_short | The energetic cost of early reproductive development in juvenile Antarctic krill at the Western Antarctic Peninsula |
| title_sort | energetic cost of early reproductive development in juvenile antarctic krill at the western antarctic peninsula |
| topic | Antarctic krill reproduction energy juvenile trade-off body condition |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2022.1009385/full |
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