| Full text | |
| Author(s): |
Rangel, Bianca de Sousa
[1]
;
Hammerschlag, Neil
[2, 3]
;
Sulikowski, James A.
[4]
;
Moreira, Renata Guimaraes
[1]
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Inst Biociencias, Dept Fisiol, Lab Metab & Reprod Organismos Aquat, Rua Matao, Travessa 14, 321, Cidade Univ, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 - USA
[3] Univ Miami, Leonard & Jayne Abess Ctr Ecosyst Sci & Policy, Coral Gables, FL 33146 - USA
[4] Arizona State Univ, Sch Math & Nat Sci, Glendale, AZ 85306 - USA
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | MARINE ECOLOGY-PROGRESS SERIES; v. 664, p. 149-163, APR 15 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Knowledge of the nutritional requirements of apex predators is key for determining ecological interactions. However, an understanding of how diet is influenced by reproduction, and the consequences of foraging variation on the nutritional status of a predator, is limited. Here, we used short-term dietary markers (plasma and whole-blood fatty acids) integrated with reproductive hormones (17 beta-estradiol and testosterone) and ultrasonography as a non-lethal approach to investigate the effect of life stage on nutritional status and trophic dynamics of female tiger sharks Galeocerdo cuvier. Despite their generalist feeding behavior, female tiger sharks fed on different food sources and/or modulated their fatty acid metabolism depending on the reproductive context. This suggests some adjustment in their nutritional requirements associated with changes in their reproductive state. Plasma and whole-blood fatty acids indicated distinct dietary sources across life stages, with a high dependence on coastal/benthic food resources during juvenile life stages, and on pelagic/oceanic and reef-associated food resources during adult life stages. Higher percentages of highly unsaturated omega-3 fatty acids found in females during their reproductive cycles suggest the dependency on these fatty acids as a source of metabolic energy during reproduction. A high percentage of arachidonic acid (ARA) found in plasma of gravid females suggests the possibility of a selective diet of ARA-rich prey species and/or selective mobilization of ARA from stored energy during gestation. Based on our findings, we propose a conceptual model of expected changes in nutritional and trophic markers across life stages of female tiger sharks. (AU) | |
| FAPESP's process: | 17/25273-0 - Ecophysiology and trophic relationships of elasmobranchs: biomarkers as tools for conservation |
| Grantee: | Bianca de Sousa Rangel |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach |
| Grantee: | Carlos Arturo Navas Iannini |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |