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Lipid, fatty acid and energy density profiles of white sharks: Insights into the feeding ecology and ecophysiology of a complex top predator

Citation

Pethybridge, HR and Parrish, CC and Bruce, BD and Young, JW and Nichols, PD, Lipid, fatty acid and energy density profiles of white sharks: Insights into the feeding ecology and ecophysiology of a complex top predator, PLoS One, 9, (5) Article e97877. ISSN 1932-6203 (2014) [Refereed Article]


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Copyright Statement

Copyright: 2014 Pethybridge et al. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.1371/journal.pone.0097877

Abstract

Lipids are major sources of metabolic energy in sharks and are closely linked to environmental conditions and biological cycles, such as those related to diet, reproduction and migration. In this study, we report for the first time, the total lipid content, lipid class composition and fatty acid profiles of muscle and liver tissue of white sharks, Carcharodon carcharias, of various lengths (1.53.9 m), sampled at two geographically separate areas off southern and eastern Australia. Muscle tissue was low in total lipid content (<0.9% wet mass, wm) and was dominated by phospholipids (>90% of total lipid) and polyunsaturated fatty acids (3412% of total fatty acids). In contrast, liver was high in total lipid which varied between 5181% wm and was dominated by triacylglycerols (>93%) and monounsaturated fatty acids (3612%). With knowledge of total lipid and dry tissue mass, we estimated the energy density of muscle (18.40.1 kJ g−1 dm) and liver (34.13.2 kJ g−1 dm), demonstrating that white sharks have very high energetic requirements. High among-individual variation in these biochemical parameters and related trophic markers were observed, but were not related to any one biological or environmental factor. Signature fatty acid profiles suggest that white sharks over the size range examined are generalist predators with fish, elasmobranchs and mammalian blubber all contributing to the diet. The ecological applications and physiological influences of lipids in white sharks are discussed along with recommendations for future research, including the use of non-lethal sampling to examine the nutritional condition, energetics and dietary relationships among and between individuals. Such knowledge is fundamental to better understand the implications of environmental perturbations on this iconic and threatened species.

Item Details

Item Type:Refereed Article
Keywords:white sharks, fatty acid, energy density profiles, feeding ecology, complex top predators,
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and Estuarine Ecology (incl. Marine Ichthyology)
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Marine Flora, Fauna and Biodiversity
Author:Pethybridge, HR (Miss Heidi Pethybridge)
Author:Nichols, PD (Dr Peter Nichols)
ID Code:118610
Year Published:2014
Web of Science® Times Cited:6
Deposited By:IMAS - Directorate
Deposited On:2017-07-14
Last Modified:2017-08-16
Downloads:12 View Download Statistics

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