Tracing the flow of dietary energy sources, especially in systems with a high degree of omnivory, is an ongoing challenge in ecology. In aquatic systems, one of the persistent challenges is in differentiating between autochthonous and allochthonous energy sources to top consumers. Bulk carbon stable isotope values of aquatic and terrestrial prey often overlap, making it difficult to delineate dietary energy pathways in food webs with high allochthonous prey subsidies, such as in many northern temperate waterbodies. We conducted a feeding experiment to explore how fatty acid stable isotopes may overcome the challenge of partitioning autochthonous and allochthonous energy pathways in aquatic consumers. We fed hatchery‐reared Arctic Char (
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Coordinated spawning of marine animals releases millions of planktonic eggs into the environment, known as egg boons. Eggs are rich in essential fatty acids and may be an important lipid subsidy to egg consumers. Our aim was to validate the application of fatty acid and stable isotope tracers of egg consumption to potential egg consumers and to confirm egg consumption by the selected species. We conducted feeding experiments with ctenophores, crustaceans and fishes. We fed these animals a common diet of Artemia or a commercial feed (Otohime) and simulated egg boons for half of them by intermittently supplementing the common diet with red drum (Sciaenops ocellatus) eggs for 10–94 days. Controls did not receive eggs. Fatty acid profiles of consumers fed eggs were significantly different from those of controls 24 h after the last egg-feeding event. Consumers took on fatty acid characteristics of eggs. In fishes and ctenophores, fatty acid markers of egg consumption did not persist 2–5 days after the last egg-feeding event, but markers of egg consumption persisted in crustaceans for at least 5–10 days. Additionally, consumption of eggs, which had high values of δ15N, led to δ15N enrichment in crustaceans and a fish. We conclude that fatty acids and nitrogen stable isotope can be used as biomarkers of recent egg consumption in marine animals, validating their use for assessing exploitation of egg boons in nature.
more » « less- Award ID(s):
- 2023618
- NSF-PAR ID:
- 10475229
- Publisher / Repository:
- The Company of Biologists
- Date Published:
- Journal Name:
- Journal of Experimental Biology
- Volume:
- 226
- Issue:
- 22
- ISSN:
- 0022-0949
- Subject(s) / Keyword(s):
- ["Counter-gradient, Energy flow, Egg consumer, Trophic linkages, Sciaenops ocellatus"]
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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A free
Plain Language Summary can be found within the Supporting Information of this article. -
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